Heat Loss due to Infiltration & VentilationInfiltration

1.1 x [(ACH x vol.) /60] x (Ti -To)-or-

.018 x ACH x Vol. x (Ti- To)Note: CFM = (ACH x volume) / 60 min per hour

Ventilation 1.1 x [( Ra x SF) + (No. of people x Rp)]

x (Ti –To) Area out Outdoor Rate (based on SF)

People Outdoor Air Rate (based number of people )

Heat Loss Due to InfiltrationInfiltration

Please Note: For tight construction use 0.5 for ACH.For medium construction use .85 for ACH.For loose construction use 1.3 for ACH.For really bad construction use 2.0 for ACH

For the summer months (cooling) use 70% of the winter values.

Heat Gains from Occupant Loads

Sensible per occupant X number of occupants = Btu h

Latent per occupant X number of occupants = Btu h

Heat Gains from Infiltration Loads

SensibleBtu h = 1.1 x CFM x TD

Latent Btu h = 4,500 x CFM x (Wroom – Woa)

Heat Gains from Outside Air for Ventilation Loads Sensible

Btu h = 1.1 x CFM x TD

Latent Btu h = 4,500 x CFM x (Wroom – Woa)

-or-Btu h = .68 x CFM x (W2 – W1)

Degree DaysTemperatures between 600 and 800

Fahrenheit are comfortable. Temperatures between 600 and 800 are

nicknamed the Goldilocks Zone. Degree days HDD heating is based on each

degree below the base of 650 U.S. 60o in Great Britain

Degree days CDD cooling is based on each degree above the base of 800 U.S. 60o in Great Britain

Degree Days for Pullman

HDD = 6655CDD = 1154

Degree Day = 65°F - ((high temp. – low temp])/2)

FormulaOperating Hours = [Degree Days x 24] /

[ Temperature Difference]

Heating Degree Days for Pullman = HDD = 6655 (look up)

Temperature Difference =ΔT (for project)

FormulaOperating Hours = [Degree Days x 24] /

[ Temperature Difference]

Heating Degree DaysExample: The Kirk Building

Operating Hours = (6655 x 24)/87 Operating Hours = 1,836

FormulaOperating Hours = [Degree Days x 24] /

[ Temperature Difference]

Cooling Degree Days for Pullman = CDD = 1154

Temperature Difference =ΔT (for project)

FormulaOperating Hours = [Degree Days x 24] / [ Temperature Difference]

Cooling Degree DaysExample: The Kirk Building

Operating Hours = (1154 x 24)/25 Operating Hours = 1,108

Estimating Annual Energy

Heating $/Yr

Electric (BTU/Hr) * (hours of operation) * $/energy

unit BTU/energy Unit * Efficiency

Electric conversion = 3,400 BTU h/KilowattEfficiency = 1.0Note: Does not include fan energy. Add 10% for

residential and 20% for commercial fan energy

Estimating Annual Energy

Heating $/Yr

Gas (BTU/Hr) * (hours of operation) * $/energy

unit BTU/energy Unit * Efficiency

Electric conversion = 100,000 BTU h/ThermEfficiency = 80% - 96% Note: Does not include fan energy. Add 10% for

residential and 20% for commercial fan energy

Estimating Annual Energy

Cooling $/Yr

(Btu/Hr) * (hours of operation) * $/energy unit

SEER * 1000

Note: Does not include fan energy. Add 10% for residential and 20% for commercial fan energy

Estimating Annual Energy

SEER Seasonal Energy Efficiency Ratio

The U.S. Department of Energy claims energy we use in an average house is responsible for twice as many greenhouse gas emissions as an average car.

Estimating Annual Energy

Estimating Annual Energy

SEER Seasonal Energy Efficiency RatioThe efficiency of central air conditioning regulated

by the U.S. Department of Energy (DOE). The SEER is defined as the total cooling output (in

British thermal units or Btu) provided by the The change from SEER 10 to SEER 13 represented

a 30 percent improvement in energy efficiency.

SEER = (seasonal Btu of cooling) / (seasonal watt-hours of electricity used)

Estimating Annual Energy

SEER Seasonal Energy Efficiency Ratio

Great strides have been made in the last 10 years in efficiency of air conditioners and heat pumps.

SEER ratings for air conditioning and air-source heat pump systems manufactured today range from 13 SEER to 24.

Central air conditioners that are in the top 25 percent of efficient may carry the ENERGY STAR® label. To qualify, they must have a minimum SEER efficiency level of 14

Estimating Annual Energy

Example: The Kirk BuildingHeating $/Yr

(2,324,056) * (hours of operation) * $/energy unit

BTU/energy Unit * Efficiency

Note: Does not include fan energy. Add 10% for residential and 20% for commercial fan energy

Electrical Cost to Heat[(BTU/Hr) * (hours of operation) * $/energy unit]/

BTU/energy Unit * Efficiency

.08 electrical cost per kilowatt hours

[(2,310,240) * (1,836) * .08]/ (3,400 * 1 .00) = $99,802.37