Many people work from home at least one day per week. Working from home saves energy and time by cutting out the commute, but it may increase your home energy bills unless you use energy-saving office equipment.

ENERGY STAR-labeled office equipment is widely available. It can provide dramatic energy savings—as much as 90% savings for some products. Overall, ENERGY STAR-labeled office products use about half the electricity of standard equipment. Find ENERGY STAR products and standards.

HOME OFFICE TIPS Selecting energy-efficient office equipment and turning off machines when they are not in

use can result in significant energy savings.

Using an ENERGY STAR-labeled computer can save 30%-65% energy than computers

without this designation, depending on usage.

Spending a large portion of time in low-power mode not only saves energy but helps equip-

ment run cooler and last longer.

Putting your laptop AC adapter on a power strip that can be turned off (or will turn off

automatically) can maximize savings; the transformer in the AC adapter draws power con-

tinuously, even when the laptop is not plugged into the adapter.

Using the power management settings on computers and monitors can cause significant

savings.

It is a common misperception that screen savers reduce a monitor's energy use. Use

automatic switching to sleep mode or simply turn it off.

Another misperception, carried over from the days of older mainframe computers, is that

equipment lasts longer if it is never turned off.

LONG-TERM SAVINGS TIPConsider buying a laptop for your next computer upgrade; laptops use much less energy than desktop computers.

HOME ELECTRONICS TIPS Look for energy-saving ENERGY STAR home electronics.

Unplug appliances, or use a power strip and use the switch on the power strip to cut all power to the appliance, to avoid "vampire" loads. Many appliances continue to draw a small amount of power when they are switched off. These vampire loads occur in most appliances that use electricity, such as DVD players, TVs, stereos, computers, and kitchen appliances. Unplug battery chargers when the batteries are fully charged or the chargers are not in use.

Use rechargeable batteries for products like cordless phones and digital cameras. Studies have shown they are more cost effective than disposable batteries. If you must use disposables, check with your trash removal company about safe disposal options.

Estimate the energy consumption and cost to operate an appliance when making a purchase. Investing in an energy-efficient product may save you money in the long run. | Photo courtesy of iStockphoto.com/wh1600.

If you're trying to decide whether to invest in a more energy-efficient appliance or you'd like to determine your electricity loads, you may want to estimate appliance energy consumption.

FORMULA FOR ESTIMATING ENERGY CONSUMPTIONUse this formula to estimate an appliance's energy use:

(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption

1 kilowatt (kW) = 1,000 Watts

Multiply this by the number of days you use the appliance during the year for the annual consumption in kWh per year.

ESTIMATING ANNUAL COST TO RUN AN APPLIANCE

Multiply the annual consumption in kWh per year (that you calculated above) by your local

utility's rate per kWh consumed to calculate the annual cost to run an appliance.

 

Note: To estimate the number of hours that a refrigerator actually operates at its maximum

wattage, divide the total time the refrigerator is plugged in by three. Refrigerators, although

turned "on" all the time, actually cycle on and off as needed to maintain interior temperatures.

EXAMPLES:Window fan:(200 Watts × 4 hours/day × 120 days/year)  ÷  1000= 96 kWh × 11 cents/kWh= $10.56/yearPersonal Computer and Monitor:[(120 Watts + 150 Watts) × 4 hours/day × 365 days/year] ÷ 1000= 394 kWh × 11 cents/kWh= $43.34/yearWATTAGEYou can usually find the wattage of most appliances stamped on the bottom or back of the appliance, or on its nameplate. The wattage listed is the maximum power drawn by the appliance. Since many appliances have a range of settings (for example, the volume on a radio), the actual amount of power consumed depends on the setting used at any one time.

If the wattage is not listed on the appliance, you can still estimate it by finding the current draw (in amperes) and multiplying that by the voltage used by the appliance. Most appliances in the United States use 120 volts. Larger appliances, such as clothes dryers and electric cooktops, use 240 volts. The amperes might be stamped on the unit in place of the wattage. If not, find a clamp-on ammeter -- an electrician's tool that clamps around one of the two wires on the appliance -- to measure the current flowing through it. You can obtain this type of ammeter in stores that sell electrical and electronic equipment. Take a reading while the device is running; this is the actual amount of current being used at that instant.

When measuring the current drawn by a motor, note that the meter will show about three times more current in the first second that the motor starts than when it is running smoothly.

Many appliances continue to draw a small amount of stand-by power when they are switched "off." These "phantom loads" occur in most appliances that use electricity, such as VCRs, televisions, stereos, computers, and kitchen appliances. Most phantom loads will increase the appliance's energy consumption a few watt-hours. These loads can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance.

TYPICAL WATTAGES OF VARIOUS APPLIANCESHere are some examples of the range of nameplate wattages for various household appliances:

Aquarium = 50–1210 Watts

Clock radio = 10

Coffee maker = 900–1200

Clothes washer = 350–500

Clothes dryer = 1800–5000

Dishwasher = 1200–2400 (using the drying feature greatly increases energy consumption)

Dehumidifier = 785

Electric blanket (Single/Double) = 60 / 100

Fans

Ceiling = 65–175

Window = 55–250

Furnace = 750

Whole house = 240–750

Hair dryer = 1200–1875

Heater (portable) = 750–1500

Clothes iron = 1000–1800

Microwave oven = 750–1100

Personal computer

CPU - awake / asleep = 120 / 30 or less

Monitor - awake / asleep = 150 / 30 or less

Laptop = 50

Radio (stereo) = 70–400

Refrigerator (frost-free, 16 cubic feet) = 725

Televisions (color)

19" = 65–110

27" = 113

36" = 133

53" - 61" Projection = 170

Flat screen = 120

Toaster = 800–1400

Toaster oven = 1225

VCR/DVD = 17–21 / 20–25

Vacuum cleaner = 1000–1440

Water heater (40 gallon) = 4500–5500

Water pump (deep well) = 250–1100

Water bed (with heater, no cover) = 120–380

Home appliance energy ratings explainedThe running costs of household appliance can vary a lot. It is important to look for efficient products with low running costs. Understanding home appliance energy ratings can help you save energy and reduce your energy costs.

Choosing energy efficient appliancesHousehold appliances account for up to 30% of your home energy, so selecting the most energy efficient appliances can save you money.

The Australian Government has an Energy Rating Labelling scheme to help customers choose energy efficient appliances. The labels apply to both electric and gas appliances.

Electric appliances      Energy Rating Labels are on televisions, air conditioners, clothes dryers, dishwashers, washing machines, and most fridges and freezers.

There are two labels: the standard 6-star and the 10-star for more efficient appliances, which are rated 7 stars and higher.

The label displays the appliance's energy efficiency and how much energy it uses in a year. The more stars, the more efficient the appliance is compared to other models, which can mean lower energy usage and potential energy savings. As the consumption figure on the label is an average level of usage, you should consider whether your usage is likely to differ from the average.  

You can use the Australian Government’s Energy Rating website  to compare the energy efficiency of electrical appliances. When comparing appliances, make sure you compare models of a similar size, volume and capacity.

Gas appliancesGas Energy Rating Labels can be found on gas space heaters, ducted heating and gas water heaters (storage and instantaneous). As the scheme is voluntary, not all manufacturers will have Gas Energy Rating Labels.

The labels display a star rating for energy efficiency and annual energy consumption in MJ (megajoules) per year—the lower this figure (MJ), and the higher the number of stars, the more efficient the appliance.

Energy StarENERGY STAR®  from the US Environmental Protection Agency is used by several countries, including Australia. Products earn the Energy Star label by

meeting energy efficiency requirements contained in Energy Star product specifications. In Australia, items such as computers, televisions, printers, photocopiers and DVD players can carry the Energy Star label.

Tips: Smart Appliances

Some manufacturers are now offering "smart" appliances -- appliances that can be connected to smart electric meters or home energy management systems to help you shift your electricity use to off-peak hours. Air conditioners, refrigerators, dishwashers, and other appliances may be available as smart appliances.

Smart appliances don't just turn off during times of peak electricity demand -- instead, they use subtle ways to shift energy use. You might not even be aware of it. For example, your air conditioner may run slightly less often. Or your refrigerator might delay it's defrost cycle until the middle of the night. If your utility charges lower rates for electricity at night, also called time-based rates, you could save on your utility bill.

Such changes may be unnoticeable to you, but could add up to significant savings for your utility -- savings that can be shared with you. Your utility provider can tell you more about the availability of smart grid technologies and time-based electricity rates in your area and how they can benefit you.

10 most costly appliancesAaron Crowe

Jun 10th 2010 11:00AM

The average U.S. household will spend about $2,160 this year on home energy, which is $60 less than in 2009, according to the Alliance to Save Energy . 

While the drop is good news, $2,160 is still a lot of money to spend on gas and electricity, and it can be cut by up to 30% by using efficient Energy Star products built to save energy, according to Ronnie Kweller, director of media relations at the

Alliance to Save Energy. Since major appliances use the most energy in a home , they're the best place to look to save money.

Start with how you heat and cool your home. Almost half, 47%, of the $2,200 it took to power a typical American home in 2009 is from heating and cooling. According to a 2009 study by Lawrence Berkeley National Laboratory, here's how the average annual utility bill is broken down by appliance, along with some tips I've collected on how to lower costs:

1. Heating: $662A home's heating, ventilation and air conditioning (HVAC) system is the worst offender, especially during the winter. The best way to save money here is to insulate and seal all ducts and air leaks so your money isn't flying out the window, or a crack in the window. A home can save 20% on its heating and cooling bills by sealing holes, Kweller said. Other things to do include having the equipment serviced

each year, replacing air filters every three to five months, and installing a programmable thermostat to turn down the heat while you're asleep or at work.

2. Cooling: $394The same rules apply here as for heating, so insulate, seal ducts and cracks, and use a programmable thermostat. If you have a central air system, clean the ducts periodically. For a room air conditioner, be sure the window unit fits tightly so outside air isn't getting in. If replacing windows, choose Energy Star qualified models designed for your area, and save $20-$95 each

year in energy costs, according to EnergyStar.gov, a U.S. Department of Energy website.

Federal tax credits  that are worth 30% of the cost of each improvement, up to a cumulative total of $1,500, are available through the end of 2010, so now may be a good time to replace an aging HVAC system or do other home improvements to save energy. Eligible products fall into two basic categories: the "building envelope," which includes windows, storm windows, storm doors, certain types of roofs, and insulation and sealing products such as caulking, weather stripping, and foam sealants; and highly efficiency heating and cooling equipment, including furnaces, boilers, heat pumps, water heaters, and central AC system. Installation costs are NOT covered for building envelope products but are covered for heating and cooling equipment.

3. Water heater: $317A water heater uses 14% of an average home's energy costs, working around the clock to heat water for clothes, dishes and showers. A new, energy efficient water heater can cut the water heating bill in half. When replacing water heaters, consider a tankless model that only heats water on demand – particularly if you have natural gas available.

Setting the water heater thermostat to 120 Fahrenheit or lower will save money by reducing standby losses (heat lost from water heater into surrounding basement area). Using less hot water will also save money. If set too high, or at 140 degrees Fahrenheit, your water heater can waste anywhere from $36 to $61 annually in standby heat losses and more than $400 in demand losses, according to the DOE. If you have an older water heater, you can improve its insulation by wrapping it with an insulating jacket and save more than $30 per year in excess heat loss.

4. Lighting: $269This makes up 12% of an energy bill. The Environmental Protection Agency estimates that if every U.S. household replaced just one traditional light with an Energy Star-qualified bulb, America would save enough energy to light 6 million homes, save $600 million in utility bills, and reduce enough greenhouse gas emissions to equal the removal of 1

million cars from the road. Compact fluorescent light bulbs use less energy and last up to 10 times longer than standard incandescent light bulbs, saving money on energy bills and replacement costs.

5. Clothes dryer, washer: $143Major appliances account for about 13% of a home's energy use, with a clothes washer and dryer the largest consumer at 6%. Many states have sales tax holidays   this summer, making it a good time to buy energy efficient appliances such as washers. Washing full loads of laundry in cold water is a good start to saving money, saving more than $40 annually from an

electric water heater and $30 from a gas water heater. An energy efficient washer will wring more water out of clothes, cutting drying time in half.

The dryer uses more energy, so using it less will save more. Moisture sensors

will turn off a dryer as soon as the clothes are dry, preventing the common problem of over-drying clothes. As your mom probably told you, clean the lint trap before every load, which will increase drying efficiency.

6. Refrigerator: $95Using 4% of a home's annual energy doesn't sound like much, but it's still money out of your pocket that can easily be reduced. New energy efficient models are so much better than old ones. Even though new ones are bigger and have more features, they still use much less energy than older models. "If it's 10 to 15 years old you are losing money all the time you are running

it," Kweller said. And buying a new one, but putting the old one in the garage and plugging it in, negates the savings. A refrigerator retirement savings calculator  can help determine how much yours costs to run.

Keep it at 35 to 38 degrees Farenheit, allow air circulation behind it, minimize the amount of time the door is open, keep the fridge full so it won't lose as much coolness when the door is opened, and check the gaskets around the door. If a piece of paper can easily be pulled out with the door closed on it, the

gaskets may be worn and need to be replaced.

7. Electric oven: $90 per year, although this figure isn't from the Berkeley study but from an energy use website . Annual cost is based on using a 350-degree oven for one hour per day. This is a rough estimate and may be much lower if you don't use the oven as much.

All else being equal, an oven with a self-cleaning feature will tend to be better insulated and thus more efficient than one which does not, according to the Alliance to Save Energy. Also avoid excessive use of the self-cleaning option, put lids on pans, and use range burners that are the same size or slightly

smaller than the pan being used. Also, replace electric ranges and ovens with gas ones if possible, and avoid gas ovens and ranges with continually burning pilot lights.

8. TV, DVD, VCR: $57These add up to 3% of a home's energy use. One easy way to save electricity is to plug them all into a power

strip and then turn the strip off when they're not being used, since standby mode can still use several watts of power. There are devices that will tell you how much energy is being sucked by things you thought were "off."

9. Dishwasher: $49Dishwashers are 2% of a typical utility bill and are another easy area to cut. Rinsing dishes can use up to

20 gallons of water before the dishes are even loaded, according to the DOE. Just scrape food off dishes, since Energy Star qualified dishwashers and today's detergents are designed to do the cleaning so you don't have to. Dishwashers use about the same amount of energy and water regardless of the

number of dishes inside, so run full loads whenever possible. And turn off the heat drying.

10. Computer: $28Using a computer and monitor make up 1% of a utility

bill. Simple tips include using a power strip that is turned off when not in use, and turning off the computer when it won't be used for more than 30 minutes. When looking to buy a new computer, remember that laptops use significantly less energy than desktop models, and LCD flat panel screens use less energy than the bigger CRT displays.

The energy crisis has given rise to a growing set of energy myths. In this article, researcher Evan Mills of Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division reviews the myths and then lay out the facts.

Myth: When my appliance is turned off, it�s off.

Fact: We�ve found that most devices continue to consume power when they�re switched off, sometimes as much power as when they�re on! A surprisingly large number of electrical products -- from air conditioners to VCRs -- cannot be switched completely off without unplugging the device. These products draw power 24 hours a day, often without the knowledge of the consumer. We call this power consumption "standby power."

Myth: Fluorescent lighting is unhealthy.

Fact: Fluorescent lighting has changed dramatically in the last few years. Today�s fluorescents have greatly improved color quality. And the annoying  flicker and hum has been eliminated from fluorescents that use electronic ballasts. Of course, fluorescents are more efficient than standard incandescent lighting. Because they require less electricity, fluorescents generate less power plant pollution, emissions which have many known health effects. Flourescent lights also contain small amounts of mercury, and should be disposed of properly. However, even more mercury releases are avoided thanks to reduced use of the mercury-containing fossil fuels used to generate electricity. If it�s been awhile since you tried fluorescent lights, you might give them another chance.

Myth: Halogen lighting is super-efficient.

Fact: It�s true that halogen lights use less energy than standard incandescent bulbs. However, compact fluorescent lights are nearly three-times as efficient as halogen and don�t have the energy-hogging transformers. Also, halogens require transformers that can use extra energy, even when the light is off.

Myth: Cleaning refrigerator coils improves efficiency.

Fact: While this seems intuitively logical, and very small savings may indeed arise, efforts to actually measure this effect on residential refrigerators have typically come up empty-handed.

Myth: Leaving lights, computers, and other appliances on uses less energy than turning them off and also makes them last longer.

Fact: The small surge of power created when some devices are turned on is vastly smaller than the energy used by running the device when it is not needed. While it used to be the case that cycling appliances and lighting on and off drastically reduced their useful lifetimes, these problems have been largely overcome through better design.

Myth: Energy efficiency products increase the initial cost of houses.

Fact: While efficient products usually cost more, in some cases there is no, or even less initial cost. Most efficient products are also premium products (in terms of features, warranty, etc.), so it's difficult to say what you are paying for the efficiency. In some instances, efficiency can even reduce first cost as in the case where smaller "down-sized" heating and cooling systems can be installed if they�re highly

efficient. Smaller units with high efficiency generate as much heating or cooling benefit as large, inefficient ones.

Myth: Insulating the ceiling will just cause more heat to leak out of the windows.

Fact: Adding insulation to one part of a home won�t increase the "pressure" on heat losses through other parts. However, it is certainly true that poorly insulated areas will be the major loser of heat and they often merit attention before improving already well-insulated parts of the home.

Myth: Switching to electric room heaters will reduce your energy bill.

Fact: This is true only under some circumstances. If you have central electric heating, then using room heaters will most likely save you money. But, if you have central gas heating (which is far cheaper per unit of useful heat), you can easily match or even exceed your heating bill by switching to electrical units. Further details online.

Myth: Electric heating is more efficient than fuel-based heating.

Fact: It�s true that all, or almost all, of the electricity that goes into an electric heater is transformed to useful heat in your home. However, making electricity is an inefficient process, with as much as two-thirds of the input energy (coal, natural gas, etc.) being lost in the process. This is why electricity is so much more expensive for the consumer than direct fuels.

Myth: Buying an efficient air conditioner or furnace will automatically reduce my utility bill.

Fact: This is true to some extent, but you won't realize all the possible savings if the equipment is not sized or installed properly. Studies have shown that typical air conditioner and duct systems are improperly installed, wasting one third or more of the energy used by the air conditioner. New and replacement equipment (and ducts) need to be properly designed and installed to realize all the possible savings. The same caveats about proper installation hold true for insulation, windows and many other energy-efficiency upgrades.

Myth: Installing foam gaskets in electrical outlets will significantly reduce air leakage.

Fact: Measurements have shown that less than one percent of a home�s air leakage is due to electrical outlets.

The energy we use is usually measured in kilowatt-hours (kWh); 1 kWh is equal to 1,000 watts working for one hour. In 2001, the entire world consumed 13.9 trillion kilowatt-hours (kWh) of electricity [source: Clean-Energy]. Of that global 13.9 trillion kWh, 25 percent (3.45 trillion kWh) powered electrical devices in the United States [source: IndexMundi]. And of that 3.45 trillion kWh, 1.14 trillion were used in households [source: EIA]. That's more than 30 percent of U.S. electricity going to power homes, which is more than either the commercial or the industrial sector uses [source: EIA].

Why the huge glut of energy consumption in the residential sector? Simple: Home appliances draw extreme amounts of energy. An appliance rated at 1,000 watts, left on for one hour, will use 1 kWh of electricity. Now think about all the appliances -- large and small -- you have in your home.

Over the last 30 years, the efficiency of many appliances has increased dramatically. A refrigerator manufactured in 1979 consumed between 120 and 300 kWh per month; in a post-2001 unit, that monthly range is down to 31 to 64 kWh [source: Hawaiian Electric]. But still, refrigerators are a big draw on the energy supply. And they're not alone.

Small appliances like toasters, hair dryers, coffee makers, vacuum cleaners and curling irons all use more watts than refrigerators do. Ranges and dishwashers do, too (you've probably noticed a trend -- producing heat takes lots of watts). But these big-watt items are only on for short periods of time, so they don't use as much power as an appliance that draws fewer watts but works indefinitely -- like a fridge/freezer or a water heater.

So for the biggest energy hogs in the home, we're left with the household appliances that we leave running for hours -- or days -- at a time. In this article, we'll take a look at five of the most energy-hungry appliances in our homes.

No. 5 on the list is refrigerator/freezers. Despite their huge efficiency jump in the last few decades, they still rank high in energy use.

ThermostatFrom Wikipedia, the free encyclopedia

This article is about the temperature regulating device. For the French cooking oven temperature scale, see Gas Mark#Other cooking temperature scales.

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2009)

Honeywell's iconic "The Round" model T87 thermostat, one of which is in the Smithsonian.

A Honeywell electronic thermostat in a retail store

A thermostat is a component of a control system which senses the temperature of a system so that the system's temperature is maintained near a desired setpoint. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. The name is derived from the Greek words thermos "hot" and statos "a standing".

A thermostat may be a control unit for a heating or cooling system or a component part of a heater or air conditioner. Thermostats can be constructed in many ways and may use a variety of sensors to measure the temperature. The output of the sensor then controls the heating or cooling apparatus. A thermostat may switch on and off at temperatures either side of the setpoint the extent

of the difference is known as hysteresis and prevents too frequent switching of the controlled equipment.

Early technologies included mercury thermometers with electrodes inserted directly through the glass, so that when a certain (fixed) temperature was reached the contacts would be closed by the mercury. These were accurate to within a degree of temperature.

Common sensor technologies in use today include:

Bimetallic  mechanical or electrical sensors Expanding wax pellets Electronic thermistors and semiconductor devices Electrical thermocouples

These may then control the heating or cooling apparatus using:

Direct mechanical control Electrical signals Pneumatic signals

Contents  [hide] 

1   History 2   Mechanical thermostats

o 2.1   Bimetal o 2.2   Wax pellet

2.2.1   Automotive 2.2.2   Shower and other hot water controls

o 2.3   Gas expansion o 2.4   Pneumatic thermostats

3   Electrical and analog electronic thermostats o 3.1   Bimetallic switching thermostats o 3.2   Simple two wire thermostats

3.2.1   Millivolt thermostats 3.2.2   24 volt thermostats 3.2.3   Line voltage thermostats

4   Digital electronic thermostats 5   Thermostats and HVAC operation

o 5.1   Ignition sequences in modern conventional systems o 5.2   Combination heating/cooling regulation o 5.3   Heat pump regulation o 5.4   Thermostat location o 5.5   Dummy thermostats

6   See also 7   References 8   External links

History[edit]

Possibly the earliest recorded examples of thermostat control were built by Cornelius Drebbel around 1620 in England. He invented a mercury thermostat to regulate the temperature of a chicken incubator.[1] This is one of the first recordedfeedback-controlled devices.

Modern thermostat control was developed in the 1830s by Andrew Ure, a Scottish chemist, who invented the bi-metallic thermostat. The textile mills of the time needed a constant and steady temperature to operate optimally, so to achieve this, Ure designed the bimetallic thermostat, which would bend as one of the metals expanded in response to the increased temperature and cut off the energy supply.[2]

The first electric room thermostat was invented in 1883 by Warren S. Johnson of Wisconsin.[3]

[4] Albert Butz invented the electric thermostat and patented it in 1886.

One of the first industrial uses of the thermostat was in the regulation of the temperature in poultry incubators. Charles Hearson, a British engineer, designed the first modern incubator for eggs that was taken up for use on poultry farms in 1879. The incubators incorporated an accurate thermostat to regulate the temperature so as to precisely simulate the experience of an egg being hatched naturally.[5]

Mechanical thermostats[edit]

This covers only devices which both sense and control using purely mechanical means.

Bimetal[edit]

Domestic water and steam based central heating systems have traditionally been controlled by bi-metallic strip thermostats, and this is dealt with later in this article. Purely mechanical control has been localised steam or hot-water radiator bi-metallic thermostats which regulated the individual flow. However, Thermostatic Radiator Valves (TRV) are now being widely used.

Purely mechanical thermostats are used to regulate dampers in some rooftop turbine vents, reducing building heat loss in cool or cold periods.

Some automobile passenger heating systems have a thermostatically controlled valve to regulate the water flow and temperature to an adjustable level. In older vehicles the thermostat controls the application of engine vacuum to actuators that control water valves and flappers to direct the flow of air. In modern vehicles, the vacuum actuators may be operated by small solenoids under the control of a central computer.

Wax pellet[edit]

Automotive[edit]Main article: Wax thermostatic element

Car engine thermostat

Perhaps the most common example of purely mechanical thermostat technology in use today is the internal combustion engine cooling system thermostat, used to maintain the engine near its optimum operating temperature by regulating the flow ofcoolant to an air-cooled radiator. This type of thermostat operates using a sealed chamber containing a wax pellet that melts and expands at a set temperature. The expansion of the chamber operates a rod which opens a valve when the operating temperature is exceeded. The operating temperature is determined by the composition of the wax. Once the operating temperature is reached, the thermostat progressively increases or decreases its opening in response to temperature changes, dynamically balancing the coolant recirculation flow and coolant flow to the radiator to maintain the engine temperature in the optimum range.

On many automobile engines, including all Chrysler Group and General Motors products, the thermostat does not restrict flow to the heater core. The passenger side tank of the radiator is used as a bypass to the thermostat, flowing through the heater core. This prevents formation of steam pockets before the thermostat opens, and allows the heater to function before the thermostat opens. Another benefit is that there is still some flow through the radiator if the thermostat fails.

Shower and other hot water controls[edit]A thermostatic mixing valve uses a wax pellet to control the mixing of hot and cold water. A common application is to permit operation of an electric water heater at a temperature hot enough to kill Legionella bacteria (above 60C/140F), while the output of the valve produces water that is cool enough to not immediately scald (49C/120F).

Gas expansion[edit]

Thermostats are sometimes used to regulate gas ovens. It consists of a gas-filled bulb connected to the control unit by a slender copper tube. The bulb is normally located at the top of the oven. The tube ends in a chamber sealed by a diaphragm. As the thermostat heats up, the gas expands applying pressure to the diaphragm which reduces the flow of gas to the burner.

Pneumatic thermostats[edit]

A pneumatic thermostat is a thermostat that controls a heating or cooling system via a series of air-filled control tubes. This "control air" system responds to the pressure changes (due to temperature) in the control tube to activate heating or cooling when required. The control air typically is maintained on "mains" at 15-18psi (although usually operable up to 20 psi). Pneumatic thermostats typically provide output/ branch/ post-restrictor(for single-pipe operation) pressures of 3-15psi which is piped to the end device (valve/ damper actuator/ Pneumatic-Electric switch, etc.).[6]

The pneumatic thermostat was invented by Warren Johnson in 1895[7] soon after he invented the electric thermostat. In 2009, Harry Sim was awarded a patent for a pneumatic-to-digital interface[8] that allows pneumatically controlled buildings to be integrated with building automation systems to provide similar benefits as DDC.

Electrical and analog electronic thermostats[edit]

Bimetallic switching thermostats[edit]

Bimetallic thermostat for buildings.

Water and steam based central heating systems have traditionally had overall control by wall-mounted bi-metallic strip thermostats. These sense the air temperature using the differential expansion of two metals to actuate an on/off switch. Typically the central system would be switched on when the temperature drops below the set point on the thermostat, and switched off when it rises above, with a few degrees of hysteresis to prevent excessive switching. Bi-metallic sensing is now being superseded by electronic sensors. A principal use of the bi-metallic thermostat today is in individual electric convection heaters, where control is on/off, based on the local air temperature and the set point desired by the user. These are also used on air-conditioners, where local control is required.

Simple two wire thermostats[edit]

Milivolt thermostat mechanism

The illustration is the interior of a common two wire heat-only household thermostat, used to regulate a gas-fired heater via an electric gas valve. Similar mechanisms may also be used to control oil furnaces, boilers, boiler zone valves, electric attic fans, electric furnaces, electric baseboard heaters, and household appliances such as refrigerators, coffee pots, and hair dryers. The power through the thermostat is provided by the heating device and may range from millivolts to 240 volts in common North American construction, and is used to control the heating system either directly (electric baseboard heaters and some electric furnaces) or indirectly (all gas, oil and forced hot water systems). Due to the variety of possible voltages andcurrents available at the thermostat, caution must be taken when selecting a replacement device.

1. Set point control lever. This is moved to the right for a higher temperature. The round indicator pin in the center of the second slot shows through a numbered slot in the outer case.

2. Bimetallic strip  wound into a coil. The center of the coil is attached to a rotating post attached to lever (1). As the coil gets colder the moving end — carrying (4) — moves clockwise.

3. Flexible wire. The left side is connected via one wire of a pair to the heater control valve.4. Moving contact attached to the bimetal coil. Thence, to the heater's controller.5. Magnet . This ensures a good contact when the contact closes. It also provides hysteresis to

prevent short heating cycles, as the temperature must be raised several degrees before the contacts will open. As an alternative, some thermostats instead use a mercury switch on the end of the bimetal coil. The weight of the mercury on the end of the coil tends to keep it there, also preventing short heating cycles. However, this type of thermostat is banned in many countries due to its highly and permanently toxic nature if broken. When replacing these thermostats they must be regarded as chemical waste.

6. Fixed contact screw. This is adjusted by the manufacturer. It is connected electrically by a second wire of the pair to the thermocouple and the heater's electrically operated gas valve.

Not shown in the illustration is a separate bimetal thermometer on the outer case to show the actual temperature at the thermostat.

Millivolt thermostats[edit]

As illustrated in the use of the thermostat above, all of the power for the control system is provided by a thermopile which is a combination of many stacked thermocouples, heated by the pilot light. The thermopile produces sufficient electrical power to drive a low-power gas valve, which under control of one or more thermostat switches, in turn controls the input of fuel to the burner.

This type of device is generally considered obsolete as pilot lights can waste a surprising amount of gas (in the same way a dripping faucet can waste a large amount of water over an extended period), and are also no longer used on stoves, but are still to be found in many gas water heaters and gas fireplaces. Their poor efficiency is acceptable in water heaters, since most of the energy "wasted" on the pilot still represents a direct heat gain for the water tank. The Millivolt system also makes it unnecessary for a special electrical circuit to be run to the water heater or furnace; these systems are often completely self-sufficient and can run without any external electrical power supply. For tankless "on demand" water heaters, pilot ignition is preferable because it is faster than hot-surface ignition and more reliable than spark ignition.

Some programmable thermostats - those that offer simple "millivolt" or "two-wire" modes - will control these systems.

24 volt thermostats[edit]The majority of modern heating/cooling/heat pump thermostats operate on low voltage (typically 24 volts AC) control circuits. The source of the 24 volt AC power is a control transformer installed as part of the heating/cooling equipment. The advantage of the low voltage control system is the ability to operate multiple electromechanical switching devices such asrelays, contactors, and sequencers using inherently safe voltage and current levels.[9] Built into the thermostat is a provision for enhanced temperature control using anticipation. A heat anticipator generates a small amount of additional heat to the sensing element while the heating appliance is operating. This opens the heating contacts slightly early to prevent the space temperature from greatly overshooting the thermostat setting. A mechanical heat anticipator is generally adjustable and should be set to the current flowing in the heating control circuit when the system is operating. A cooling anticipator generates a small amount of additional heat to the sensing element while the cooling appliance is not operating. This causes the contacts to energize the cooling equipment slightly early, preventing the space temperature from climbing excessively. Cooling anticipators are generally non-adjustable.

Electromechanical thermostats use resistance elements as anticipators. Most electronic thermostats use either thermistor devices or integrated logic elements for the anticipation function. In some electronic thermostats, the thermistor anticipator may be located outdoors, providing a variable anticipation depending on the outdoor temperature. Thermostat enhancements include outdoor temperature display, programmability, and system fault indication. While such 24 volt thermostats are incapable of operating a furnace when the mains power fails, most such furnaces require mains power for heated air fans (and often also hot-surface or electronic spark ignition) so no functionality is lost. In other circumstances such as piloted wall and "gravity" (fanless) floor and central heaters the low voltage system described previously may be capable of remaining functional when electrical power is unavailable.

Terminal codes and colors:

Terminal Code

Color Description

R Red 24 volt

RH / RC Red 24 volt HEAT / COOL load

C / X Blue 24 volt Common (Ground)

W / W1 White Heat

W2 White Backup Heat

Y / Y1 Yellow Cool

Y2Purple/Yellow/White

Cool Second Stage

G Green Fan

O / OB Orange Reversing valve (Heat Pump)

E Emergency Heat (Heat Pump)

S1/S2 Brown/Black/BlueTemperature Sensor (Usually outdoors on a Heat Pump System)

Line voltage thermostats[edit]Line voltage thermostats are most commonly used for electric space heaters such as a baseboard heater or a direct-wired electric furnace. If a line voltage thermostat is used, system power (in the United States, 120 or 240 volts) is directly switched by the thermostat. With switching current often exceeding 40 amperes, using a low voltage thermostat on a line voltage circuit will result at least in the failure of the thermostat and possibly a fire. Line voltage thermostats are sometimes used in other applications, such as the control of fan-coil (fan powered from line voltage blowing through a coil of tubing which is either heated or cooled by a larger system) units in large systems using centralized boilers and chillers, or to control circulation pumps in hydronic heating applications.

Some programmable thermostats are available to control line-voltage systems. Baseboard heaters will especially benefit from a programmable thermostat which is capable of continuous control (as are at least some Honeywell models), effectively controlling the heater like a lamp dimmer, and gradually increasing and decreasing heating to ensure an extremely constant room temperature (continuous control rather than relying on the averaging effects of hysteresis). Systems which include a fan (electric furnaces, wall heaters, etc.) must typically use simple on/off controls.

Digital electronic thermostats[edit]

See also: Programmable thermostat

Residential digital thermostat

Lux Products' Model TX900TS Touch Screen Thermostat.

Newer digital thermostats have no moving parts to measure temperature and instead rely on thermistors or other semiconductor devices such as a resistance thermometer (resistance temperature detector). Typically one or more regularbatteries must be installed to operate it, although some so-called "power stealing" digital thermostats use the common 24 volt AC circuits as a power source, but will not operate on thermopile powered "millivolt" circuits used in some furnaces. Each has an LCD screen showing the current temperature, and the current setting. Most also have a clock, and time-of-day and even day-of-week settings for the temperature, used

for comfort and energy conservation. Some advanced models have touch screens, or the ability to work with home automation or building automation systems.

Digital thermostats use either a relay or a semiconductor device such as triac to act as switch to control the HVAC unit. Units with relays will operate millivolt systems, but often make an audible "click" noise when switching on or off.

More expensive models have a built-in PID controller, so that the thermostat knows ahead how the system will react to its commands. For instance, setting it up that temperature in the morning at 7 a.m. should be 21°C, makes sure that at that time the temperature will be 21°C, where a conventional thermostat would just start working at that time. The PID controller decides at what time the system should be activated in order to reach the desired temperature at the desired time. It also makes sure that the temperature is very stable (for instance, by reducing overshoots[citation needed]).

Most digital thermostats in common residential use in North America and Europe areprogrammable thermostats, which will typically provide a 30% energy savings if left with their default programs; adjustments to these defaults may increase or reduce energy savings.[citation needed] The programmable thermostat article provides basic information on the operation, selection and installation of such a thermostat.

Thermostats and HVAC operation[edit]

Ignition sequences in modern conventional systems[edit]

Gas

1. Start drafting fan (if the furnace is relatively recent) to create a column of air flowing up the chimney

2. Heat ignitor or start spark-ignition system3. Open gas valve to ignite main burners4. Wait (if furnace is relatively recent) until the heat exchanger is at proper operating

temperature before starting main blower fan or circulator pump

Oil

1. Similar to gas, except rather than opening a valve, the furnace will start an oil pump to inject oil into the burner

Electric

1. The blower fan or circulator pump will be started, and a large electromechanical relay or TRIAC will turn on theheating elements

Coal (including grains such as corn, wheat, and barley, or pellets made of wood, bark, or cardboard)

1. Generally rare today (though grains and pellets are increasing in popularity); similar to gas, except rather than opening a valve, the furnace will start a screw to drive coal/grain/pellets into the firebox

With non-zoned (typical residential, one thermostat for the whole house) systems, when the thermostat's R (or Rh) and W terminals are connected, the furnace will go through its startup rituals and produce heat.

With zoned systems (some residential, many commercial systems — several thermostats controlling different "zones" in the building), the thermostat will cause small electric motors to open valves or dampers and start the furnace or boiler if it's not already running.

Most programmable thermostats will control these systems.

Combination heating/cooling regulation[edit]

Depending on what is being controlled, a forced-air air conditioning thermostat generally has an external switch for heat/off/cool, and another on/auto to turn the blower fan on constantly or only when heating and cooling are running. Fourwires come to the centrally-located thermostat from the main heating/cooling unit (usually located in a closet, basement, or occasionally in the attic): One wire usually red, supplies 24 volts AC power to the thermostat, while the other three supply control signals from the thermostat, usually white for heat, yellow for cooling, and green to turn on the blower fan. The power is supplied by a transformer, and when the thermostat makes contact between the 24 volt power and one or two of the other wires, a relay back at the heating/cooling unit activates the corresponding heat/fan/cool function of the unit(s).

A thermostat, when set to "cool", will only turn on when the ambient temperature of the surrounding room is above the set temperature. Thus, if the controlled space has a temperature normally above the desired setting when the heating/cooling system is off, it would be wise to keep the thermostat set to "cool", despite what the temperature is outside. On the other hand, if the temperature of the controlled area falls below the desired degree, then it is advisable to turn the thermostat to "heat".

Heat pump regulation[edit]

 

Thermostat design

The heat pump is a refrigeration based appliance which reverses refrigerant flow between the indoor and outdoor coils. This is done by energizing a reversing valve(also known as a "4-way" or "change-over" valve). During cooling, the indoor coil is an evaporator removing heat from the indoor air and transferring it to the outdoor coil where it is rejected to the outdoor air. During heating, the outdoor coil becomes the evaporator and heat is removed from the outdoor air and transferred to the indoor air through the indoor coil. The reversing valve, controlled by the thermostat, causes the change-over from heat to cool. Residential heat pump thermostats generally have an "O" terminal to energize the reversing valve in cooling. Some residential and many commercial heat pump thermostats use a "B" terminal to energize the reversing valve in heating. The heating capacity of a heat pump decreases as outdoor temperatures fall. At some outdoor temperature (called the balance point) the ability of the refrigeration system to transfer heat into the

building falls below the heating needs of the building. A typical heat pump is fitted with electric heating elements to supplement the refrigeration heat when the outdoor temperature is below this balance point. Operation of the supplemental heat is controlled by a second stage heating contact in the heat pump thermostat. During heating, the outdoor coil is operating at a temperature below the outdoor temperature and condensation on the coil may take place. This condensation may then freeze onto the coil, reducing its heat transfer capacity. Heat pumps therefore have a provision for occasional defrost of the outdoor coil. This is done by reversing the cycle to the cooling mode, shutting off the outdoor fan, and energizing the electric heating elements. The electric heat in defrost mode is needed to keep the system from blowing cold air inside the building. The elements are then used in the "reheat" function. Although the thermostat may indicate the system is in defrost and electric heat is activated, the defrost function is not controlled by the thermostat. Since the heat pump has electric heat elements for supplemental and reheats, the heat pump thermostat provides for use of the electric heat elements should the refrigeration system fail. This function is normally activated by an "E" terminal on the thermostat. When in emergency heat, the thermostat makes no attempt to operate the compressor or outdoor fan.

Thermostat locationThe thermostat should not be located on an outside wall or where it could be exposed to direct sunlight at any time during the day. It should be located away from the room's cooling or heating vents or device, yet exposed to general airflow from the room(s) to be regulated.[10] An open hallway may be most appropriate for a single zone system, where living rooms and bedrooms are operated as a single zone. If the hallway may be closed by doors from the regulated spaces then these should be left open when the system is in use. If the thermostat is too close to the source controlled then the system will tend to "short cycle", and numerous starts and stops can be annoying and in some cases shorten equipment life. A multiple zoned system can save considerable energy by regulating individual spaces, allowing unused rooms to vary in temperature by turning off the heating and cooling.

Dummy thermostatsIt has been reported that many thermostats in office buildings are non-functional dummy devices, installed to give tenants' employees an illusion of control.[11]

[12] These dummy thermostats are in effect a type of placebo button. However, these thermostats are often fully functional in the sense that they are used to detect the temperature in the zone, even though their controls are disabled and not used in lieu of the environmental controls of the building. This function is often referred to as "lockout".[13]

What uses more energy, heat or AC?

BY JOSHUA KEATING

MAY 10, 2013 - 11:25 AM

   

As the weather starts to heat up here in D.C., local businesses will begin keeping the temperature at refrigerator-like levels of coolness. When it comes to energy use and environmental impact, air conditioning tends to get more heat, so to speak, but as the University of Michigan's Michael Sivak finds, the heating needs of people in the frigid north are actually more of a problem: Energy demand for climate control was analyzed for Miami (the warmest large metropolitan area in the US) and Minneapolis (the coldest large metropolitan area). The following relevant parameters were included in the analysis: (1) climatological deviations from the desired indoor temperature as expressed in heating and cooling

degree days, (2) efficiencies of heating and cooling appliances, and (3) efficiencies of power-generating plants. The results indicate that climate control in Minneapolis is about 3.5 times as energy demanding as in Miami. This finding suggests that, in the US, living in cold climates is more energy demanding than living in hot climates.[...]

To the surprise of many, air conditioners are more energy efficient than furnaces or boilers. Another way of stating this is that it takes less energy to cool down an interior space by one degree than to heat it up by one degree. This is the case, because (in layman's terms) it takes less energy to transfer heat (air conditioners) than to generate heat (furnaces and boilers).[...]

The traditional discussion of climatology and energy demand concentrates on the energy demands for cooling in hot climates. However, the present results indicate that the focus should be paid to the opposite end of the scale as well: In the US, living in cold climates (e.g., in Minneapolis, Milwaukee, Rochester, Buffalo, and Chicago) is more energy demanding than is living in hot climates (e.g., in Miami, Phoenix, Tampa, Orlando, or Las Vegas).On the other hand, world demand for air conditioning is soaring -- potentially growing as much as 40-fold this century -- as temperatures rise and middle classes grow

in formerly poor warm-weather countries, while the demand the global demand for heating is relatively constant. Air conditioners are becoming more efficient but perhaps not fast enough to keep up with this growth.

20 tips to save energyCebu Daily NewsFirst Posted 15:40:00 08/04/2008Filed Under: Consumer Issues,  Energy & Resources

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In light of the surging energy crisis, the Cebu Chamber of Commerce and Industry (CCCI) appeals to the public to observe the energy efficient practices.

CCCI gathered suggestions from its member companies to share fuel and energy saving measures. The results were trimmed to 20 practical methods that could be done easily in the workplace and homes.

1. Always turn off the lights when leaving a room.

2. Use compact fluorescent light bulbs. They use less electricity and last up to 10 times longer than incandescent bulbs.

3. Make sure that bulbs, fixtures, lenses, lamps and reflective surfaces are cleaned regularly. By removing the grease, dust and other dirt, you can increase the output of your lights. 

4. Refrigerator accounts for 11 percent of a household's total energy consumption. Today's energy-efficient refrigerators use 50 percent less energy than old models.

5. Organize food on refrigerator shelves to allow ample airflow and efficient operation.

6. Chest freezers are more energy efficient than upright models. Cold air stays in better when the door is opened.

7. A room air conditioner filter should be cleaned once per quarter. A dirty air filter reduces airflow and may even damage the unit.

8. A poorly performing air conditioner should be serviced without delay. A leaking refrigerant not only reduces the unit's efficiency, it also emits greenhouse gases that contribute to climate change.

9. Using a microwave oven instead of a conventional oven can save 50?percent of cooking energy costs. Microwave ovens cook food faster than conventional ovens.

10. Oven toaster uses much less energy than a conventional oven. It is also faster and more convenient for cooking small quantities of food. 

11. Iron clothes in bulk once a week.

12. Give your car a break. Combine trips whenever possible. Use mass transit, walk or bike whenever possible. Leaving your car at home just two days a week will save 1,590 pounds of greenhouse gas emissions each year. 

13. Always maintain your car to maximize its fuel efficiency, safety and reliability. 

14. Refrain from charging cellular phones when the battery is not yet fully empty. This does not only save energy, it also prevents damage on your cellular phones.

15. Unplug any battery chargers or power adapters when not in use.

16. Activate ?sleep? features on computers, copiers and other machines that power down when the equipment is on but not in use for a while. Turn off equipment during long periods of non-use to cut energy costs.

17. Use lap top computers since they use up to 90 percent less energy than a standard computer. 

18. Consider using ink-jet printers which also use 90 percent less energy than laser printers. 

19. Choose a flat-panel computer monitor rather than a regular cathode ray tube (CRT) monitor. Some flat-panel liquid crystal display monitors use considerably less electricity than comparably-sized CRT models. Prices for LCD monitors have been dropping. Buy the smallest monitor. The bigger the monitor, the more energy it uses. A 17-inch monitor consumes 35 percent more electricity than a 14-inch monitor. 

20. Implement paper-reducing strategies, such as double-sided printing, re-using paper and using e-mail instead of sending memos or faxing documents to save energy and conserve other resources.

Efficiency how to: 12 clever ways to save lots of electricity and money (and by the way: also the planet) 'The clever way: better with less'

Heating and cooling

This web page concentrates on electricity use in households. It should, however, be noted that in moderate and cold climate zones, space heating takes up at least half of the overall energy use.

Therefore, proper insulation and ventilation is the first and most important energy saving measure. It can reduce heating needs to one-third (about 50 kWh heat/m2/y) or even one tenth (less than 15 kWh heat/m2/y) of what an average house would need. Remarkably, a properly insulated house, which only needs a third of the heat to keep you warm, will not be more expensive to build. The extra investments in insulation, ventilation and high-efficiency glazing, can be offset by a smaller and cheaper heating system. An efficient house will also be healthier and more comfortable to live in - it avoids 'cold radiation' (as from windows), the differences of temperature between heated and non-heated rooms is less, and it can be more efficiently ventilated.

In hot regions, energy use for active cooling (air conditioning) can be minimised or even avoided if the construction is well-thought out. In a moderated climate, active cooling can always be avoided.

Electricity

Electricity consumption in households differs immensely throughout the world. Even within the OECD (industrialised countries), an average European household consumes 4,667 kWh, whereas a household in the US consumes 11,209 kWh and in Japan 5,945kWh per year . A US household uses three times more electricity for lighting, and twice as much in refrigerators than in the EU. This does not necessarily reflect a difference in comfort. As we will explain, there are high efficiency appliances that consume two to 10 times less electricity for an equal functionality, and that are most often also of higher quality. Using only highly efficient and money saving appliances can reduce the electricity consumption of an average household to as low as 1,300 kWh/y, without any loss of comfort. This is almost 10 times less than the US average.

Try to minimise electricity use: its generation needs a lot of energy, mostly heat produced in coal, gas or nuclear plants. Using electric hot water heaters or space heating is extremely inefficient. At the power plant, some 60 percent of the energy is lost as waste heat. Another 10 percent is lost in electricity lines and transformers before the electricity even reaches your home.

  1. Use efficient lighting

  Replace incandescent bulbs with compact fluorescents (CFLs). Compact fluorescents use four times less energy, and last eight times longer (8,000h instead of 1,000h) than incandescent light bulbs. For example, a typical 75W incandescent bulb will be replaced by an 18W compact fluorescent. The compact fluorescent will be more expensive to buy, but you will need to replace it eight times less

often and it will use less electricity, which often makes it the biggest electricity saver in your house.  At a minimum, we recommend replacing the bulbs in all lamps that are used for 30min/day or more.

  Fluorescent tubes are even more efficient than compact fluorescent lamps, and last even longer (10,000-20,000h). Only use tubes with a modern ballast starter that avoids flickering and lights immediately - good ones add another 20 percent efficiency. Another option is a CFL with a dedicated fixture. The electronic ballast which is part of the fixture lasts 40,000 hours and bulbs can be replaced separately at lower cost.  Both CFLs and fluorescent tubes are available in a dimmable fixtures. This can increase comfort, save even more energy and extend the lifetime of the bulb.

  Especially avoid halogen floor lamps, which typically have a power of 300W or more, produce lots of heat and are actually so hot (some 500° Celsius) that they can cause serious burns and start fires. Besides, on hot summer days they are very uncomfortable to be around. A CFL floor lamp only uses 50-80W at 40° Celsius. They can save loads of energy and even your life.

  Also pay attention to the light fixtures. Clever use of reflectors, and directional lamps to get the light where you need it can save you another 50 percent energy cost and improve your comfort! Well thought out use of efficient lights can thus reduce electricity needs up to 8 times.

  CFLs at the end of their operating life should be disposed of properly so the mercury inside can be recycled.  To be clear, even if not recycled, CFLs are still the better choice, since the inefficiency of  incandescent and halogen lights causes far greater environmental damage - including mercury emissions from coal fired power plants.  (But  please do recycle the CFLs.)

  Also, conversion to efficient lighting often leads to an increase in the use of light. To some degree, this can be a positive effect, as it can increase comfort and your well-being. But it can also lead to wasting light, such as leaving lamps on when there is no need to (e.g. when you leave the room). This is reinforced by the misconception that turning CLFs  on and off is expensive. As a general rule, always turn off the lights when you leave the room or the house.

  For more information see the Rocky Mountains Institute.

  2. Buy efficient electric appliances.

  They use two to 10 times less electricity for the same functionality, and are mostly higher quality products that last longer than the less efficient ones. In short, efficient appliances save you lots of energy and money.

  In many countries, efficiency rating labels are mandatory on most appliances. In the EU, models are labelled A++ for the most efficient, then A+, A, B, C, D for subsequently less efficient models. Look for the A++ or A+ models. In the US, the Energy Star label is used.

  The label gives you information on the annual electricity consumption. In the paragraphs below, we provide some indication of the consumption of the most efficient appliances to use as a rough guide when shopping. Lists of brands and models and where to find them are country-specific and so cannot be listed here, but check the links on this page for more detailed information.

  Average consumption of electric appliances in different regions in the world, compared with the high efficient models on the market

3. Refrigerators:

Buy a high efficiency refrigerator that consumes around 100 kWh/y. This is 10 times less than the average in the US, and four times less than  the EU average.

Remarkably, energy consumption by the most efficient refrigerator models is largely unrelated to their size. The most efficient 400-litre fridge on the market today only consumes 106kWh/y.

These efficient refrigerators are about 5-15 percent more expensive to buy, but will save you loads of money and energy in use. In general, they are also high quality products that will last longer, will need less repairing and make less noise.

Avoid refrigerators with a built-in frozen food compartment, if you have a separate freezer. These models are less efficient and you loose cooling space.

4. Freezers:

For most home consumers it is better to buy a two door refrigerator/freezer combination with separate compartments, than a separate refrigerator and freezer. Refrigerator/freezer combinations where the freezer is at the top or bottom of the unit  are generally better than ones with side by side doors. Of course, you should always compare energy consumption ratings, pay attention to energy efficiency labels (see above), and look for Greenfreeze technology.

This award-winning two door refrigerator/freezer only consumes 137kWh/year.

Chest type models are more efficient than uprights.

Unlike refrigerators, with freezers size does matter. Larger freezers do need more electricity. So don't buy a freezer that is larger than you need, especially if you live close to the store.

The most efficient models on the market will only use 180 kWh for a 300 litre chest, and 240 kWh/y for a large 450 litre freezer chest.  The best upright models range from 170 kWh for a 190 litre model to 220 kWh for a 310 litre model.

5. Clothes washing machines

Buy a high-efficiency model with a power consumption of less than 0.9 kWh/washing cycle.

Consider a 'hot fill' model which connects directly to your efficient gas-fired water heater. Using gas to heat the water almost halves electricity consumption.. Installing a hot fill appliance needs to be done correctly, so good advice is required.

Check the energy label. The EU A+/A/A label will guarantee you the best energy efficiency and washing and drying result.

If using a clothes dryer,  make sure that your washing machine can spin at 1600 or even 1800 rpm.

The most efficient washing machines save some 1,500 litres of water per year - a double gain!

6. Clothes dryers

Traditional clothes dryers are very energy intensive. So-called 'condensation' models - without an exhaust tube - use even more energy.

Consider drying the natural way (i.e. on a clothes line outdoors) if practical, this will save you 3-4 kWh/washing cycle.

If line drying is not an option, first make sure that your washing machine can spin at 1600 or even 1800 rpm. This will almost halve the energy needed for drying. Drying through spinning is 20 times less energy intensive than with heat.

There are two clothes-drying technologies that use far less energy: the gas-fired clothes dryer and the dryer with an electric heat pump. The gas-fired dryer is the best alternative, especially for more intensive use: it uses 60 percent less energy (including the gas) and dries 40 percent faster. If gas is not available, consider a dryer with a heat pump. A heat pump dryer will use half the electricity of a traditional dryer. However, heat pumps can be rather expensive.

7. Dishwashers

An efficient dishwasher consumes no more than one kWh/washing cycle, compared with 1.4 kWh for an average model.

Consider a 'hot fill' model which connects directly to your efficient gas fired hot water heater. That way, gas is used to heat the water instead of electricity, thereby reducing electricity consumption by 50 percent, or even up to 90 percent for the top models. This is because gas is almost twice as efficient for heating water as electricity. Note that installing a 'hot fill' needs to be done properly so good advice is required.

8. Computers and IT

Buy a laptop instead of a desktop, if practical. It consumes five times less electricity.

If you buy a desktop, get an LCD screen instead of an outdated CRT.

Enable the power management function on your computer, the screensaver does not save energy.

Check if your computer supports the more advanced Speedstep™ power management.

Switching off a computer extends its lifetime, contrary to some misconceptions. Leaving a computer running the whole year will cost you more than 1,000 kWh/y, or almost as much a the total electricity consumption of a high-efficiency household.

Use one large power strip for your computer, broadband modem, scanner, printer, monitor, and speakers. Switch it off when equipment is not in use. This is a practical way to cut 200 kWh/y or more of standby losses (see standby).

Minimise printing. Laser printers use more electricity than inkjet printers.

For more information see Greencampus Harvard and the Rocky Mountains Institute.

9. Cut off standby losses ("The vicious energy-suckers")

Most modern electric appliances consume electricity even when turned off. For TVs, VCRs, faxes, HiFis, computer screens, cable boxes, and broadband modems this is on average some 40 - 120 kWh/y. In total, household losses can reach several hundreds kWhs/y, all for doing nothing useful.

The best solution is to buy appliances that have a very low standby energy consumption. Standby power consumption is mentioned in the product manual and can be checked before buying. Or you can look for it on specialised websites  (see links). For most appliances, it should be around 0.5 - 1 watts/hour or 4-8 kWh/year. Keep in mind that the cost of wasted standby energy over  a model's lifetime can be higher than the cost of buying it!

A power strip is also the most practical way to switch of VCR, TV and DVD-player stand-by losses (you can cut off all three devices at once).

The multi socket power strip: a practical way to combat stand-by losses. This model costs only 1.8 euro and can save you more than 100kWh/y!

In the 15 countries of the EU in 2000, the total energy lost to standby in households was estimated at 94 billion kWh, or the equivalent of 12 large nuclear or coal power plants. The fast growth of inefficient ICT and multimedia applications could nearly double this in 10 years.

10. Do not use an electric boiler (hot water heater) for hot water ("Heat the water, not the sky!")

An electric boiler consumes about 3,200 kWh/y (average OECD). But producing that electricity in highly inefficient gas, coal or nuclear plants, and then transmitting that electricity down the power line to your home costs some 9,600 kWh in electricity wasted as heat - so roughly 2/3rds of the energy is lost before it even reaches  your home. Using gas or oil directly to heat water reduces energy use to 3,800 kWh.

A solar boiler can further halve that figure to 1,900 kWh in a moderate climate zone (and even less in sunny regions) - for a total energy savings of about five times what the electric boiler uses. However, do not use a solar boiler combined with an electric heating, as this will be less efficient than a gas boiler alone - the energy cost of the electric heating usually wipes out the savings gained by the solar boiler. 

11. Use a water-saving shower head

The water-saving shower head delivers high comfort for only half of the water use (5-7 litres/min. Instead of 10-18 litres/min.).

Hot water is the second most important area of energy use in a household, after space heating, and thus needs extra attention. An efficient shower head can save almost 1,500 kWh electricity/y if an electric boiler is used, or 1,900 kWh heat if a gas or oil boiler/geyser is used.  All this for just a few dollars/euros extra when you buy the showerhead. Over its lifetime of 10 years, a showerhead will also save some 70,000 litres of water.

Using a water-saving showerhead, combined with a solar boiler reduces energy needs to some 950 kWh heat (gas or oil), or almost 10 times less than when an electric boiler is used with a traditional shower head!

12. Do not use electric space heating

Same reasons as for the electric boiler. Instead add insulation, and (ideally) heat your house using a renewable energy solution like solar thermal.  However, gas heating is still far better than electric heating.

Interested in doing more? Check out more green living tips from Greenpeace in Canada.

To learn more about energy efficiency you can visit the following links:

  Asia Energy Revolution   Blogging for Greenpeace: Do your part   Check out our animations section for some fun and helpful tips on living green

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5 Surprising Ways to Lower Your MERALCO BillIs your electric bill spiraling out of control?For most households, utility bills make up a huge chunk of their monthly expenses. And it doesn’t matter if it’s summer season or not; Electric bill will always remain as long as our need for comfort and convenience exists.

But you don’t need to keep pulling your hair out over a skyrocketing MERALCO bill. As long as you have the will to change

some habits and learn few money-saving tips from now on, a lower MERALCO bill is just one leap away.Listed below are some of the lesser known tipid tips you can apply on your appliances today. Please take note that refrigerator, lighting fixtures, and air-conditioning units consume the most energy so emphasis have been given to them. 

Keep your refrigerator full (but not TOO full)

Refrigerators eat up 15 to 20 percent of household electricity. For this reason, extra care must be observed both in buying and maintaining one.We all know that frequently opening the refrigerator can cause heat to enter the unit. And the more heat trapped inside, the higher the operating cost will be.

But the effect is doubled once you leave your refrigerator empty. This is because more space in the unit means more cold air will escape once the door is opened.

To keep the coolness intact, it is recommended to fill both the refrigerator and the freezer with necessary items like bottled water. These will displace the empty air and avoid unnecessary energy waste every time the door is opened. Just be extra careful not to overload it, though, because too much stuff in your ref can also take its toll on your electric bill.

Bonus tip: If you’re shopping for new refrigerator, choose a unit with high Energy Efficiency Factor or EEF. This information is usually printed in a yellow label attached in every unit. The higher the EEF, the more cost- and energy-efficient the refrigerator is. [Image source] 

 

Avoid oversized aircons

Especially during summer, air-conditioning units are one of the most indispensable appliances in the house. But the convenience it brings requires a hefty price. In fact, a 1.5 horsepower consumes electricity that costs around 2, 413 pesos per month.Needless to say, choosing the right aircon unit that suits your room is one of the best decisions you can make from the get-go.

As a standard, rooms with a size of 10 sq. meters and below must stick to the conventional window-type aircon. Rooms of up to 18 sq. m, on the other hand, will find  1.0 HP inverter split-type aircon  as a more efficient alternative. This aircon uses an inverter technology that allows the compressor to do automatic adjustment once the desired temperature is achieved. In other words, it will slow down to maintain room temperature without the need for the compressor to switch on and off. As a result, cool temperature is maintained while less power is consumed.Bonus tip: As much as possible, avoid placing heat-generating appliances such as lamps and TV sets near the aircon unit. The heat coming from these items will be recognized by the thermostat and significantly affect how much energy the aircon consumes. [Image source] 

 

Goodbye incandescent bulbs, Hello CFLs

Does changing your light bulbs becoming a pain in the ass?

If you can’t count how many times you have visited the local hardware, chances are you still use those low-cost incandescent bulbs.

Although more costly, compact fluorescent lamps (CFL) are much cheaper if you consider their long-term benefits.  CFLs last eight times longer and use 75% less energy that their cheaper counterparts.  In fact, a 16-watt CFL produces the same light as a  60-watt incandescent bulb at the fraction of the cost. In addition to that, CFLs are covered with warranty so you can easily replace one for free in case it blows up.Bonus tip: You can opt to buy dimmer switches along with your light bulbs if you seriously want to cut down on your utility bills. Dimmers help in lowering down wattage while giving you more control over lighting quality. [Image source] 

 

Switch to induction cooking

Compared to gas stoves, induction cookers are more expensive in terms of initial cost. But just like in the case of CFLs, induction cookers promise a safer and more energy-efficient way of cooking.

Although in runs in electricity, induction cookers prevent excessive heat transfer in the atmosphere. As a result, both refrigerators and aircon units won’t need to work twice harder to eliminate the heat.

Inductive cookers operate under electromagnetic induction, a process wherein  82% of the heat is directly transferred to the cooking vessel . This is in stark contrast with gas stoves which can waste up to 64% of heat during the cooking process.Bonus tip: To avoid overworking your refrigerator, place it away from heat sources such as ovens and gas stoves. [Image source] 

 

Use an electricity cost calculator

Wondering why your MERALCO bill is getting out of control? Perhaps its about time to look closer on your consuming habits and pinpoint where and when the highest energy goes into waste.

And this is when using electricity cost calculator becomes even more essential.In the case of MERALCO, a free computer application is currently available in their website. This MERALCO Appliance Calculator or M.A.C. offers two options: The My Appliance Calculator and My Bill Manager.My Appliance Calculator gives you an idea of how much energy a specific type of appliance unit can consume. This option will help those who are just trying to decide which type of appliance units to buy.My Bill Manager, on the other hand, gives you an estimate of your monthly electricity bill. It lets you know how much energy you consume for every appliance unit and therefore help you do the necessary adjustment to reduce consumption.

What are your energy-saving tips?

WORDS WORTH By Mons Romulo (The Philippine Star) | Updated May 18, 2014 - 12:00am

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In school we are taught how to conserve energy. At home we were constantly reminded by our elders to always turn off the lights, electric fans, aircons and computers when not in use. But as years have gone by, more new electrical devices have been developed and we have started to consume more and more energy than before.

Wasting energy is like wasting money. We need to conserve energy because the energy sources we depend on — like coal and natural gas — can’t be replaced. The electricity that we use comes from nuclear power, coal power plants. When burned they emit carbon dioxide, which is harmful to humans and the environment. Saving energy not only saves us money but the environment as well.

Read on as some personalities share tips on how we can conserve energy.

 

Lila Almario, shoe designer

When cooking Italian, after dropping the pasta in boiling water, shut off the stove and cover the pot with a lid. Time it and stir once in a while then test it for desired doneness. Same thing with boiling eggs.

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At bedtime, you can turn the timer of the air-conditioner on so that it automatically shuts off after several hours. You wake up to a cool room without having to get up, and you saved kilowatt hours, too.

 

Annie Ringor, president, Bridges@com

I changed all my household’s light bulbs to LED and bought all the energy-efficient appliances from Samsung. Our ironing day is reduced to just once a week, and we also unplug all electrical appliances/gadgets whenever we go out of town.

 

Parañaque Mayor Edwin Olivarez

In our “Bagong Parañaque Program,” we encourage people to turn off and unplug electrical appliances rather than putting it on standby mode; use fluorescent light instead of incandescent bulb or LED if possible; unfurl curtains and open windows to let sunlight and fresh air in minimizing the use of electrical lighting; put just the right amount of water to boil when making coffee or if you have a vacuum flask put the excess hot water in it and walk, rather than ride a vehicle.

Loud sounds and high volume also consume a lot of energy and are stressful to our ear. Lower volume to what is enough to hear.

 

Atty. Mela Bengzon

Go green in the kitchen. Renewable energy is currently the latest trend in business, and in the legal profession.  With the recent gas leak in New York that caused a building to

collapse, there now exists an imperative need to have a grasp on how to be energy-efficient and safe, especially in the kitchen.

 Have high-quality pots and pans — copper-bottom or cast-iron are best; while baking, never open the oven door; always check for cracks or tears or, even signs of wear and tear, on your oven or furnace doors. If you smell a foul odor like that of rotten eggs, you may have a gas leak. Leave the area right away, and call proper authorities.

 

Congressman Dato Arroyo

Instead of turning the lights on during the day, you can keep the windows and/or doors clear and uncovered so that the sunlight filters in.

 

Eileen Macapagal De Leon, entreprenuer

The blinking lights on fax machines, phones, printers and other appliances is 15 percent of your electric bill. So, I unplug my appliances, computer (and other gadgets) when not in use instead of standby or sleep mode. Also turning the refrigerator thermostat down by two levels consumes less energy.

 

Yvette Fernandez, editor in chief, Town & Country

I bike to and from my exercise classes since I don’t live too far away. That burns extra calories. I wish I could bike to work and elsewhere but the pollution on EDSA is just too bad. I wish they had bike lanes in Manila. I used to live in New York, and I would bike or walk to places whenever possible.

 

Maxine Eigenman, actress, podcast host

Buy LED lights, take cold showers as to not feel like being in the air-conditioned room all the time. Hit the mall and go for a movie marathon inside the cold cinema. (Laughs)

 

Carol Javier Taffs, housewife

Turn the air-conditioner off in unoccupied rooms. When buying an aircon, check out one with a lower energy-efficient ratio.  Clean the filters of air-conditioners regularly. Keep windows/doors shut when the aircon is in use. Use electric fans instead of aircon whenever possible. Power off all electrical appliances not in use. Only use hot water (water heater) when necessary. Take a shower instead of using the bathtub to save water and heating costs.

 

Nifleda Huab Wessling, mompreneur

Unfortunately, in the many cities we’ve lived in, my home has always been prone to break-in attempts — only one being successful, but enough to jar me for the rest of my life. Thus, I never want to leave the impression that my home is unoccupied especially when we are away on holiday for long periods, particularly during the winters here in London where it can be dark as early as 3 p.m. I have since discovered programmable timers, which are small devices that you install between the plug of your electrical equipment and the main socket (or extension sockets, if you like) and which allow you to control the on-off cycle of your equipment.  Nowadays, I simply position strong enough stand-alone lamps in the rooms I want lit during the dark hours and use these timers to program them to turn on and off at specific times. Most of the light bulbs I use at home are energy-saving LED bulbs.

I don’t know why my friends make fun of me for this but I also still use a traditional whistling (or screaming) kettle to boil me some water for a cup of tea or coffee.

 

Karen Vogelsang Beltran, housewife

If we do turn on the air-conditioning it’s in one room and it should be the smallest room in the house. We also stopped using a big freezer as it consumes a lot of power, too. We just go to the grocery more often. The water dispensers, which automatically cool and heat water, are also big electricity users. Cool your water in the ref and heat your water on the stove.

 

Michelle H. Lao, retailer

Lighting aromatic candles in the evening not only helps me to save on energy, it also allows me to revel in a fancy ambience and to luxuriate in a room that is filled with complexity and depth.

 

Kim Bernardo-Lokin, managing editor Business+Class magazine

We replace most of our lights to energy-saving light bulbs. which use lesser watts but are just as bright. We use curtains that block off sunlight, which is useful especially in the afternoon where it’s hottest. We also ask our kids to sleep in the room with us every time there’s no school, so we’ll use only one aircon. The kids actually find this a fun way to bond, and an added bonus was it makes us closer as a family.

 

Claire Seelin Diokno, makeup artist

Unplug all electric appliances as soon as you’re finished using them. I use a lot of lights when I work but I make sure I use energy-saving light bulbs. Meralco has an app that computes the electric consumption of each appliance so you can be sure to use each one wisely.