Step 1: Operating Costs of the Defrost Heaters
The evaporator coil has 6 face heaters. Each face heater consumes 1,824 watts. There is also one drain pan heater that draws 736 watts.
(6 face heaters x 1,824 watts’/face heater) + (1 drain pan heater x 736 watts/drain pan heater) = 11,680 watts
The defrost clock runs 4 times a day, in 15 minute cycles. That’s a total run-time of 60 minutes a day. We can now use the total watts to calculate the energy consumption in watt-hours.
11,680 watts * (1 hour) = 11.68 kWh per day = 355.3 kWh per month
The cost of electricity is $0.134 per kWh, so the true cost of the electric defrost heaters can be determined in the calculations below:
Heater operating cost:
355.3 kWh per month x ($0.134/kWh) = $47.61 per month
STEP 2: OPERATING COST OF THE (2) FAN MOTORS RUNNING 24/7
Fan motors power:
Volts per motor x Amps per motor x # of motors x Power factor (efficiency) x square root of three (for a 3-phase motor) = 460 Volts * 1 Amps * 2 * 0.83 * square root of 3 = 1,380 kW drawn by the fans
Fan motors consumption:
1,380 kW * 30.42 days/month = 1007 kWh per month = 12,089 kWh per year
The cost of electricity is $0.134 per kWh, so the true cost of the (2) fan motors running 24/7 can be determined below:
Fan motors operating cost = 12,089 kWh per year x ($0.134/kWh) = $134.99 per month
THE COST TO OPERATE THE (2) FAN MOTORS IS ALMOST 3 TIMES MORE THAN THE DEFROST HEATERS!
For more information on Frigitek™ Electronically Commuted (EC) Motors and Controllers and how Carlisle Energy can save you money, please contact us directly at (714) 684-1766.