Cambridge Space Heaters
Operating Costs
Based on 6,014 Heating Degree Days
$0.15/ft2 Gas cost @ $0.50/therm
$0.05/ft2 Electric cost @ $0.08/Kwh
$0.20/ft2 Total cost
Building Specifications
 - 105,000 ft2 x 24’ high
 
 - R-4 Roof / R-2 Walls
 
Heating System
 - (4) Cambridge Space Heaters
 
 - Roof top mounting
 
 - 6,706 MBH total
 
 - 31,000 CFM total
 
 - 22.5 HP total - intermittent
 
Air Turnover
Operating Costs
Based on 6,014 Heating Degree Days
$0.26/ft2 Gas cost @ $0.50/therm
$0.12/ft2 Electric cost @ $0.08/Kwh
$0.38/ft2 Total cost
Building Specifications
 - 105,000 ft2 x 24’ high
 
 - R-4 Roof / R-2 Walls
 
Heating System
 - (4) Air Turnover Heaters
 
 - Floor mounting
 
 - 10,000 MBH total
 
 - No outside air
 
 - 60 HP total - intermittent
 
Summary
The Cambridge system used over 45% less total energy with less temperature variation.
If the facility with air turnover heaters had installed a Cambridge system they could have saved approximately $19,000/year operating at $0.20/ft2  vs. $0.38/ft2.