Transcript Formulas - CLASSES

Heat Loss due to Infiltration &
Ventilation
Infiltration
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)
Heat Loss Due to Infiltration
Infiltration
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
Sensible
Btu 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)
-orBtu h = .68 x CFM x (W2 – W1)
Degree Days
for Pullman
 HDD = 6655
 CDD = 1154
Degree Day = 65°F ((high temp. – low
temp])/2)
Formula
Operating Hours = [Degree Days x 24] /
[ Temperature Difference]
Heating Degree Days for Pullman = HDD = 6655
Temperature Difference =ΔT (for project)
Formula
Operating Hours = [Degree Days x 24] /
[ Temperature Difference]
Cooling Degree Days for Pullman = CDD = 1154
Temperature Difference =ΔT (for project)
Estimating Annual Energy
Heating $/Yr
(BTU/Hr) * (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
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
Heating Cost for
Operating Hours = [Degree Days x 24] /
[ Temperature Difference]
[6,655 x 24]/87 = 1836
Operating Hours = 1,836
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