energy auditing 101
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Morgan KingTRANSCRIPT
Energy Auditing 101
Morgan KingCampus Lead: HSU, Chico, UCSC
Introduction
Who am I?
Training Goal:
Leave today with the motivation and know-how to conduct energy audits on your campus.
What’s on tap for today?
Energy Concepts and the Building as a System
Energy Audit Practice and tool demo
Recommendations
Strategic Planning Session
What are your expectations?
Energy True or False
When my appliance is turned off, it’s off.
Every unit of energy that goes into a power plant
gets converted into electricity.
Buying an efficient air conditioner or furnace will
reduce my energy bill.
Image Credit: Florida Public Service Commission, http://www.psc.state.fl.us/consumers/house/
Energy
Water
Materials
Useful Work
By-
Product/Was
te
Inputs Outputs
Energy Water
FuelsWaste
Environ-
mental Protect
ion
Cost Savings
Health &
Comfort
What is an energy
audit?
•Systems Approach
•Inter-relationships
•Comprehensive or
specific
•Variety of diagnostic tools
Power vs. EnergyPower – Rate of applied
work or energy
• Units: Watt, BTU/hr
Energy – Applied power X
time
• kW X hr = kWh
• BTU/hr X hr = BTU 0
100
200
300
400
500
600
700
800
900
1000
Energy
Refrigerator Example
Wa
tts
Time
BTU –British Thermal Unit - the amount of energy required to raise 1
pound of water by 1 °F ~ 1 wooden kitchen match
Natural Gas – Therm – 100,000 BTU
Electricity – kWh ~ 3414 BTU
What is Energy Efficiency?To provide the desired amount of ‘work’
for as little energy input as possible
η = Energy In – Losses
Energy In
How efficient is a 100W
incandescent light bulb?
QuestionsA 100 watt light bulb has a lifetime of 1,000 hours. How much energy
will it consume in its lifetime?
(100 W) X (1,000 hr) X (1kW/1,000 W) = 100 kWh
A 85,000 BTU/hr furnace is operated for 12 hours per day, for one full
year. How much energy has it used in BTU and in therms?
(85,000 BTU/hr) X (12 hr/day) X (365 day/yr) = 372,300,000 BTU/yr
(372,300,000 BTU/yr) X (1 therm/100,000 BTU) = 3,723 therm/yr
Energy CostsElectricity
$0.12-$0.14 per kWh
0.514 lbs CO2 per kWh
(PG&E)
1.3 lbs CO2 per kWh (US)
Natural Gas
$1.20 per therm
13.4 lbs CO2 per therm
QuestionsHow much money will it cost to operate the 100 watt light bulb
over it’s lifetime of 1,000 hours, assuming energy costs $0.125
per kWh?
(100 kWh) X ($0.125/kWh) = $12.50
How many pounds of CO2 will be emitted from using 3,723 therms/yr
to operate the furnace for a year (assuming 1 therm = 13.4 lbs
CO2)?
(3,723 therms/yr) X (13.4 lbs CO2/therm) = 49,888 lbs CO2
Building Energy ConsumptionResidential
Commercial
Core Areas of Concern:
HVAC/ Building Envelope
Water Heating
Plug Loads
Lighting
Source: EIA, Commercial Buildings Energy Consumption Survey, Table E-5A, 2008
Energy Audit Focus Areas
Focus Area Assessment Tools EE Measures
Heating/Cooling
Inspect heating/cooling equipment, distribution
system, system balance, thermostats, leaks in
envelope, building envelope upgrades
IR thermometer, Thermal Leak
Detector
Air sealing, insulation improvements, thermostat settings, window
treatments,reduce internal heat gains (cooling), smaller/more efficient
equipment
Water Heating and Cooling
Inspect water heating equipment (e.g. boilers),
pipes, fixtures, controls, usage behaviors
ThermometerLower temperature set-point,
insulate, pipe wrap, heat trap, low flow fixtures
Plug LoadsInspect plug-in equipment,
phantom loads, usage behaviors
Watt meterEnergy Star upgrade, remove
redundancy, unplugging, (smart) power strips, plug miser controls
LightingInspect age/type of lighting,
light intensity, lighting controls, usage behavior
Flicker Checker, Ballast Checker,
Light meter
Lighting Retrofit, task Lighting, lighting Controls, de-lamping
Building Shell and its implications on heating and cooling
For maximum efficiency and comfort, the
thermal boundary and air barrier must be
continuous and in contact with each other!
Building Envelope – separates
outside from inside environment
Thermal Boundary – limits heat
flow inside and outside of
conditioned space
Air Barrier – limits air flow
between inside and outside of
structure
Examples of where the thermal boundary and air barrier are not intact
Building Envelope - Insulation
Insulation – slows heat transmission, reduces
temperature fluctuations, reduces size of heating
and cooling systems, and reduces wintertime
condensation by raising surface temperatures and
preventing cool interior temperatures.
R-Value – resistance to heat loss. Higher the R the
better.
R Values are additive!
Example: What is the R-Value of the following wall
system?
Insulation: R-Value = 12 (approx 4 inches)
Exterior Siding: R-Value = 3
Interior Siding: R-Value = 3
For Cal:
Attic: R30 – 50
Wall: R13-15
Floor: R19-25
ConductanceU-Factor – measure of thermal
conductance of a building
material. Small U means poor
conductor.
U = BTU/ft2 x ºF x hour
U = 1/R
What is the R Value of a
double pane window in
a vinyl frame?
R = 1/U = 1/0.46 = 2.17
Quantifying Conductive Heat Loss
• Second Law of Thermodynamics – over time systems move from an ordered state to a disordered state
– hot to cold, moist to dry, high pressure to low pressure
• Conductive Heat loss rate
q (BTU/hr) = U (BTU/ft2 x ºF x hr) x A (ft2) x ΔT (°F)
Image Credit: Preservation Premium Windows and Siding
http://www.preservationcollection.net/i/Windows/
Example:
U = 0.46
A = 4’ X 2’
To = 48º
Ti = 68º
q = 0.46 x 8 x 20 = 73.6 BTU/h
Heating/Cooling Audit
Focus Area Assessment Tools EE Measures
Heating/Cooling
Inspect heating/cooling equipment, distribution
system, system balance, thermostats, leaks in
envelope, building envelope upgrades
IR thermometer, Thermal Leak
Detector
Air sealing, insulation improvements, thermostat
settings, window treatments, reduce internal heat gains
(cooling), smaller/more efficient equipment
Let’s do a heating/cooling audit of this room!
Water Heating/Cooling
Water Heating and Cooling
Inspect water heating/cooling equipment
(e.g. boilers), temp settings, pipes, fixtures,
usage behaviors
ThermometerLower temperature set-point, insulate, pipe wrap, heat trap,
low flow fixtures, controls
• 120º max at the tap farthest from the boiler
• Low flow fixtures• Shower heads ≤ 2.0 gpm
• Faucet aerator ≤ 2.75 gpm
• Refrigerated water fountains
Plug Loads
• Watt meter, Energy Guide, name plate, online search
Plug Load Recommendations
Behaviors
Controls
and Operations
Upgrades and
Retrofits
Eliminate
Redundancies
Plug Load Exercise
Energy Consumption Energy Costs CO2 Emissions
Plug Load
Name
Run
Watts
Phantom
Load
Watts
Operating
Hours/yr
Phantom
Load
hrs/yr
Run Load
kWh/yr
Phantom
Load
kWh/yr
Total
kWh/yr
Run Load
$/yr
Phantom
Load
$/yr
Total
$/yr
Run Load
CO2
lbs/yr
Phantom
Load
CO2
lbs/yr
Total
CO2
lbs/yr
A B C D E F G H I J K L M
#1:
Printer
#2:
Phantom load on this printer is 2.8 watts.
Run load is 250 watts.
Printer is used 500 hrs a year.
1 pound of CO2 per kWh.
$0.13 per kWh.
Recommend 200 watt printer with no
phantom load.
149
100
Lighting
There are several factors to consider when comparing lamps:
– Watt rating and kWh
– Light output, in lumens
– 100W incandescent = 1750 lumens
– 40W fluorescent = 3150 lumens
– How long lamp will last (lifetime)
– Color Rendition (CRI)
– Color Temperature
– Illuminance (foot-candles): 1 footcandle = 1 lumen/square foot
Lighting
T12 Lamps
Lamp Type fixture watts
24" T12 1 lamp 28
24" T12 2 lamp 56
24" T12 3 lamp 62
24" T12 4 lamp 112
36" T12 1 lamp 32
36" T12 2 lamp 65
36" T12 3 lamp 115
36" T12 4 lamp 136
48" T12 1 lamp 40
48" T12 2 lamp 72
48" T12 3 lamp 112
48" T12 4 lamp 142
T12/U-bend1 lamp 34
T12/U-bend2 lamp 66
T8 Lamps
Lamp Type fixture Watts
24" T8 1 lamp 15
24" T8 2 lamp 28
24" T8 3 lamp 41
24" T8 4 lamp 57
36" T8 1 lamp 23
36" T8 2 lamp 42
36" T8 3 lamp 62
36" T8 4 lamp 84
48" T8 1 lamp 25
48" T8 2 lamp 54
48" T8 3 lamp 73
48" T8 4 lamp 94
T8/U-bend 1 lamp 27
T8/U-bend 2 lamp 52
Comparison of T8 and T12 Flu oresce nt Systems
Lamp
Type
# Lamps/Watt/Le ngth Ballast Type Watts/Ft 2 CRI† Annual
Operatin g
Cost ²
T12 3/4 0W/ 48 ” T12
Magnetic 1.5 62 $4, 500
T8 3/3 2W/ 48 ” T8
Electr onic 0.8 86 $2, 400
†CRI = Color Rendering Index. The
higher the CRI, the more natural
objects will appear under a light source
∆Based on $0.12/kWh at 3,000
hrs/year operation
Lighting: De-lamping
Lighting
Illuminating
Engineering Society
(IES)
Guidelines for
Illuminance Levels
Lighting Exercise
Conduct a lighting audit of the room!
What is total energy lighting consumption?
What is total energy cost and pounds of CO2?
Any recommendations to reduce energy consumption?
Assume: $0.13/kWh and 1 lbs CO2/kWh
Economics of Energy Efficiency• The more energy a home uses, the greater the potential for savings!
• Cost variables include purchase price (capital cost), installation, life-span of retrofit, savings, and payback period
• Simple Payback (SP), Life-Cycle Savings (SLC), Savings to Investment Ratio (SIR) preferred SIR is greater than 1.1
SP = Initial Cost($) / Annual Savings($/yr)
SLC = Annual Savings($/yr) X Life expectancy (yr)
SIR = Life-Cycle Savings ($)/Initial Cost ($)
Cost Effectiveness of Retrofits
Homeowner spends $2,000 on new dbl-pane windows and receives $12 per month reduction in energy cost, what are the SP and SIR if there is a 20 year life expectancy?
SP = $2,000 ÷ $144/yr = 13.9 years
SLC = $144/yr x 20yr = $2,880
SIR = $2,880 ÷ $2,000 = 1.44
Thank You! Questions?
Morgan King
Campus Lead: HSU, Chico, UCSC