building science
TRANSCRIPT
The Science of Buildings:
Energy, Water, Indoor Air Quality, and Materials
Build It Green www.BuildItGreen.org
Presented by:
Kevin Beck, Lead Trainer
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What We Will Cover:
• The physical forces at work in a building• What is important about Energy use?• Why does Water affect everything?• What is healthy Indoor Air Quality?• What are Green Materials?
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Energy = Comfort• People don’t want energy; they want what energy
provides and they don’t want to pay a lot for it:• Hot showers and cold beer• Comfortable interiors (temperature, humidity, radiation, draft-
free, light, no glare)
• It is our job to strike the balance between comfort and energy (form, amount, pattern)
• If you deliver it cheaply, safely, and conveniently, they will use less
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Energy: The Keystone of Green Building
1. Energy Basics
2. Energy Conservation (using less)
3. Energy Efficiency (using it well)
4. Renewable Energy (acquiring new energy)
5. Understand the differences between use (EC), efficiency (EE) and acquisition/creation (RE)
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1. Energy BasicsWhat are the rules?
The laws of thermodynamics:
1st Law—Energy can neither be created nor destroyed (can only be changed from one form to another)
2nd Law—Whenever energy is changed it loses something in the process (called entropy) (i.e. “you can’t get even”)• Heat is the typical result from entropy• Heat is the “waste” or “loss” of the energy exchange process• We measure this as the efficiency of the conversion (e.g.
a 92% AFUE furnace)
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How does it work?• Heat always moves from higher concentration to
lower concentration, from hot to cold (most things work in this same manner) Note: Cold is not cold, it is just the absence of heat.
• This process typically takes place 3 ways in buildings:• Conduction• Convection• Radiation
All three can occur at once or separately
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• Heat transfer and you:• Conduction• Convection• Radiation
• From high to low
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2. Energy Conservation
Using Less:• Decreasing the energy used to operate a residence
(and provide good service)• This is accomplished via conscious design and
construction, efficient equipment, and conscious operations
• Typically, the overall kwh/therm input is the best final evaluation metric of a home or piece of equipment (how much does it ultimately use?)
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3. Energy EfficiencyUsing It Well:• Using technology to decrease energy demand• If a piece of equipment is efficient, it will use less
energy (conservation) compared to a similar inefficient piece of equipment
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4. Renewable Energy Using technology to harness solar
energy• Wind Power• Hydroelectric Systems• Solar Hot Water Systems• Solar Photovoltaic Systems• While all of these systems have value, they
should be used in the right situation; after you’ve done your conservation and efficiency efforts to the maximum
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Average CA Residential Energy Use
(Source: CA Energy Commission)
Electric Gas
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Water and Energy StatisticsWater
• Only 2.5% of the world’s water is fresh water• Only around 0.4% is available for use by people• Avg. water use per person is 70-100 gal/day NOT INCLUDING
LANDSCAPING• 40-60% of potable water is used in landscapes
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Water and Energy StatisticsWater is Inextricably Linked with Energy and Materials
• 19% of CA electricity and 32% of CA natural gas is used for water pumping, cleaning, heating (so by saving water, you are saving energy!)
• 14% of home energy is used for heating water• Water is used in every power plant for boiling to make steam to
run a turbine and for cooling that steam we just made and the machinery we just heated (So by saving energy, we are saving water!)
• Water is used in virtually every industrial process for mixing with and cleaning materials (So by conserving resources you’re saving water!)
• We can go a long time without energy, but very short time without water. We can create usable energy, but not water.
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The avg. U.S. household uses 350 gallons of water per day (inside)
SOURCE: American Water Works Association Research Foundation – percentages are rounded
Clothes Washers
22%
Toilets 27%
Showers 17%
Faucets 16%
Leaks 14%
Other 2%
Baths 2%Dishwashers 1%
Clothes Washers
22%
Toilets 27%
Showers 17%
Faucets 16%
Leaks 14%
Other 2%
Baths 2%Dishwashers 1%
Saving water saves treatment chemicals, pumping, heating energy, and power plant pollution
Where Does Indoor Water Go?
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Where Does Ext. Water Go?• 40-60% of potable water goes into the landscape• How much does it actually need? Imagine a daily water truck.• How much runs into the street?• How much sprays into the air and not on the landscape?• What could you do to change this situation? How much effort would
it take? Is that effort worth it?
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Water Conservation Strategy• Get educated on water use (www.H2ouse.net)• Conduct a Water Audit• Install Water Conserving Appliances
• EnergyStar® & WaterSense® rated
• Install Water Conserving Fixtures & Systems• Toilets, faucets, showerheads, and on-demand hot
water circulation pump
• Optimize Irrigation system• Lower Landscape Water Needs• Rainwater Harvesting• Grey-water Plumbing• Use Water Wisely
WaterSense Certifies:
Toilets (now)
Irrigation Professionals (now)
Bathroom Faucets (now)
Urinals (early 2010)
Homes (2010)
Showerheads (2010)
Irrigation Controllers (2010)
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Water & Building Materials Don’t Mix• Water vapor is everywhere• Plumbing is throughout the
house & irrigation system• It rains from time to time• We like to cook, bathe & wash• Soil is always evapo-transpiring• Too much moisture destroys
buildings and bank accounts.
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Moisture Source Impacts
Moisture Source Potential Cups• Showering 1 /shower• Dishwashing 2-4 /day• Cooking (meals for 4) 4-8 /day• Dryers venting indoors 8-12 /load• Seasonal evaporation from materials 12-28 /day• Ground moisture 0-210 /day
Source: Saturn Energy Auditor Field Guide
The Following activities add unseen moisture to the air:
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Moisture Laws
• Water follows certain rules:• It flows downhill via gravity• It flows up via capillary action• It can push through materials
via diffusion• It can go in and out of buildings
with airflow• It moves from high
concentrations to low concentrations
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Wet Soil
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Leaky Plumbing
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Indoor Air Quality (IAQ & IEQ)
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The Sleeping Giant We don’t know what we don’t know 15% of homeowners may be allergic
to elements in their own homes 40% of children born today will develop some form of
respiratory disease Prevalence of asthma has doubled since 1976 (20
million people, including 6.3 million children) Increased links to ADD and asthma in children Of all the chemicals that the EPA monitors, only 2
(ozone & sulphur dioxide) are more prevalent outdoors than indoors
- Environmental Protection Agency
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What is IAQ and IEQ? Indoor Air Quality
Formaldehyde VOCs CO Particulates
Questions Is the air in your home
(un)healthy for you? Are there dangerous gases
or pollutants in it? If so, what are they; how do
we address them?
Indoor Environmental Quality Formaldehyde VOCs CO Particulates Light Noise Vibration Temperature/Humidity
Questions How are you affected by these
things?
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How To Address IAQ IssuesThree main categories:
Moisture, Gases & Particulates
Things to consider: The chemicals already in the building The chemicals you add to the building The health of workers and occupants Future IAQ problems
Pathway to Solutions: Elimination Ventilation Filtration IAQ during construction
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First Action: Elimination Reduce the type and number of products and
causes that off-gas into the living space Solvent Based Adhesives Paints and Finishes Carpet and Fabrics Engineered Wood Products Combustion Appliances Pesticides Cleaners Hobbies Pets
Most things (except concrete, metals and glass) off-gas some mix of chemicals at some decreasing rate over some period of time. It is different for every material.
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Second Action: Ventilation Ventilation is the second way to reduce the
impact of high concentrations of unhealthy gases Natural Ventilation Mechanical Ventilation
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Third Action: Filtration Filtration takes some micro
particulates out of the air Residential filtration does not
capture gases
Remember to test your system to see if it can handle the air flow restriction of your filter!
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Volatile Organic Compounds
VOCs are typically in solvents in fluid or flexible products Paints, sealers, adhesives, caulks On-site finishes can be absorbed by other porous
materials in a home, such as carpets and furniture. Most of the ‘enes’ are VOCs (avoid them)
Gasoline Kerosene (C14H30)
Benzene (C6H6)
Xylene (C8H10)
Toluene (C7H8)
Off-gassing Carbon based Broken down and reconstructed
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Check: Label, Technical Data Sheet, or Material Safety Data Sheet Product label may show VOC levels (grams per liter)
The Technical Data Sheet is a summary of technical info promoted by the manufacturer and expected by the customer (cut sheet)
The Material Safety Data Sheet is a summary of categorized health hazard information relevant to people handling the material MSDS has nine to sixteen sections, describing 3 hazard types:
• Health Hazards (i.e. acids on skin will cause burns)• Fire Hazards (i.e. propane burns easily & may explode)• Reactivity Hazards (i.e. mixing ammonia & bleach will result in
the release of a harmful gas) None is a complete source of info; tend to be general summaries None describe laws related to the product or allergic effects We tend to follow SCAQMD regulations
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Vinyl Flooring Vinyl chloride and other dangerous emissions Vinyl flooring can trap moisture
Could promote de-lamination and mold growth Vinyl Composition Tile (VCT) is more benign than
sheet vinyl - 75-80% limestone Rule of Thumb: The softer – the more off-gassing
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Carpeting Contains: Toxic chemicals in the fibers, bonding material,
dyes, fire retardants, backing glues (white styrene butadiene latex), fungicides and antistatic and stain-resistant treatments 120 chemicals, some of which are neuro-toxic These chemicals persist for at least 3 years It is neither renewable nor bio-degradable
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Carbon Monoxide“The Silent Killer”
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Gas stove Gas furnace Gas water heater Gas dryer Gas/wood fireplace or stove Gas or charcoal grill Car/Garage It is estimated that each year carbon monoxide poisoning
kills 5,000 persons in the U.S. and injures over 10,000 persons. (Source: Carbon Monoxide Poisoning Injury.com)
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Carbon Monoxide exposure
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Carbon Monoxide Alarms Look for UL 2034 and CSA
6.19 certifications or a unit that measures low level and long term CO
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Questions
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