Cost to operate heat pump


  #1  
Old 01-13-19, 12:33 PM
L
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 251
Received 10 Likes on 10 Posts
Cost to operate heat pump

I have a three ton Goodman heat pump that I would like to estimate the cost of operation for a period of time, say one hour, without activation of the heat strips. The unit is a 16 SEER and was serviced in 2018 so I believe it is operating at its best efficiency. How can I estimate/determine the amps the unit draws so I can calculate the wattage? Is additional information needed to make the estimate? I would expect to disregard any electrical costs of the defroster if it would trigger in this time frame.

If determining the amp draw is difficult, can anyone put a knowledgable ballpark estimate for one hour operation at 15 cents per KWH?

Thanks
 
  #2  
Old 01-14-19, 07:10 AM
Z
Member
Join Date: Jan 2018
Posts: 548
Received 0 Likes on 0 Posts
From what Iíve seen, heat pumps use less than 3kw an hour for just the exterior unit. At 15 cents per kWh, youíre looking st about 45 cents for the hour. Assuming the unit runs for a full hour.

Iím still new at figuring all these costs out, so donít take my word for it.

Contractor said my 20,000 watt furnace would cost $4 an hour to use at 20 cents per kWh.

I assume youíd also need to add in the cost of the air handler fan.
 
  #3  
Old 01-14-19, 10:24 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,916
Received 3,161 Likes on 2,840 Posts
Determining the amp draw isn't difficult. It's stamped on an ID plate on the unit.
 
  #4  
Old 01-14-19, 01:00 PM
L
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 251
Received 10 Likes on 10 Posts
Thanks Pete, but isn't the boilerplate rating the maximum it can draw but not necessarily the actual draw?
 
  #5  
Old 01-14-19, 03:11 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,916
Received 3,161 Likes on 2,840 Posts
There are several ratings.... one is LRA - locked rotor amps - which is maximum and the second amp rating is the actual draw.

A 3 ton heat pump would likely draw around 20A when running. That would be 4800 watts.
The blower runs roughly 4A. That would be 480 watts.
4800 + 480 = 5280 watts = 5.3 kw x .15 = $0.795 hour. Eighty cents an hour.
 

Last edited by PJmax; 01-15-19 at 04:59 PM. Reason: corrected new math to correct math
  #6  
Old 01-15-19, 05:53 AM
L
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 251
Received 10 Likes on 10 Posts
Thanks, Pete: I had wondered what that second amp rating meant.

Your math works out closer to 80 cents/hour. (5.3 x .15 = .795)
 
  #7  
Old 01-15-19, 04:57 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,916
Received 3,161 Likes on 2,840 Posts
Ummmm..... could it be new math.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: