DOE Steep Slope Calculator

Estimates Cooling and Heating Savings for Residential Roofs with Non-Black Surfaces

Enter A State:
Enter A City:
Click to see Data for All 243 Locations
Roof Inputs: 
R-value(Btu-in/(hr ft2 oF):
Solar Reflectance (SR) Percentage: (HIGH=60;AVG=25; LOW=5):
Emittance (E) Percentage: (HIGH=90;AVG=60; LOW=10):
     
Energy Costs And Equipment Efficiencies:  
Summertime cost of electricity (HIGH=0.20; AVG=0.10; LOW=0.05) [$/KWh] : 
Air conditioner efficiency (Coefficient of Performance) (HIGH=2.5; AVG=2.0; LOW=1.5) 
Energy source for heating (choose one) :

Electric 

Non-Electric  

If electricity, wintertime cost (HIGH=0.20; AVG=0.10; LOW=0.05) [$/KWh] : 
If non-electric, cost (Natural gas: HIGH=1.30; AVG=1.00; LOW=0.70) [$/Therm]
(Fuel oil: 2004 East coast=1.40; 2004 Midwest=1.25) [$/Therm]  :
Heating system efficiency (Furnace or boiler: HIGH=0.8; AVG=0.7; LOW=0.5)   (Electric heat pump: HIGH=2.0; AVG=1.5)   (Electric resistance: 1.0) :
 
 
Net Savings [$/ft per year] :
Cooling savings [$/ft per year] 
Heating savings (heating penalty if negative) [$/ft per year] 
   
Insulation in Black Roof to Yield Same Annual Energy Savings:
Upgrade from R- to R-
 
 
Details of Comparison:   
Heating degree days for location chosen [Annual F-day]
Cooling degree days for location chosen [Annual F-day]
Solar load for location chosen [Annual Average Btu/ft per day]
Cooling load for black roof (SR=5%;IE=90%) [Btu/ft per year] 
Heating load for black roof (SR=5%;IE=90%) [Btu/ft per year] 
Cooling load for proposed roof [Btu/ft per year] 
Heating load for proposed roof [Btu/ft per year] 
   

Revised June 2005