View Full Version : Bryant Evolution Heat pump running - but its 24F!
11-24-2007, 07:39 AM
Hi, I have a Bryant Evolution heat pump system, and it is connected to a backup gas furnace. I don't think the techs ever did a proper calculation for my home.
Anyway, it is 24 degrees this AM, and the heat pump was running on low stage! Shouldn't the furnace have kicked in by now? What is the best way I can get my settings checked on the evolution control? My installer was just that, they only just hooked everything up, but didn't explain anything to me (and I don't think they understood it, either!)
Help! I don't want my electric bill to be 10X higher than it should be when the gas should be running. Or should it be? Is the system on full automatic going to make good decisions about using the heat pump preferentially over the gas system?
11-24-2007, 08:22 AM
Is it maintaining the inside temp?
11-24-2007, 10:00 AM
Call the installers back. Have them review the switchover temperature with you. They should be able to answer your questions. You are the customer.
11-24-2007, 04:22 PM
Yes it is maintaining the temp.
11-24-2007, 05:07 PM
You have two break points to consider on a dual fuel system. One is the point in which the heat pump can no longer maintain the set point temp and the other is the economic break point, which is the point when the heat pump costs more to provide heat than the secondary heat source. You would need to calculate the cost of running the heat pump at various temps and compare that to the calculated cost of running the secondary heat source. Your contractor should be able to help you with those calculations. Call the owner if the service people are not helpful.
In a very general sense, you are probably going to be able to heat your home cheaper with the heat pump, even at 24*, then using most any other source of heat. Even at 24* many heat pumps still produce 2.5 to 3 times the amount of heat than it takes in energy to operate. Unless you have rather high electric rates and low gas rates it could well be cheaper to run the heat pump. This is the beauty of heat pumps.
11-24-2007, 05:40 PM
Call whoever sold you the system, salesman or owner, and ask them to come explain to you how your system is supposed to operate. This is standard procedures included in any new system purchase.
11-24-2007, 05:57 PM
If you've got the Evolution System User Interface, there's an entire set-up procedure that the installing company must follow to properly program the system. It takes time to do it right. With a dual fuel/Hybrid Heat system like you have, it is possible to program the heat pump to 'lock-out' at any desired temperature between 0 and 55*F. If it's not programmed for lock-out, it will run the heat pump until the heat pump is no longer able to keep up with the heating demand. Then it will begin using the gas furnace to 'boost' the heat pump. But each cycle, it will begin with the heat pump until it determines the heat pump can't keep up. Sounds to me like your installers either didn't know what to do or just didn't want to take the time. As others have said, call them back and make them finish the job. That means explaining all the parameters of the system, how it's set up to operate. And they also should have left you with the User Interface Manual, as there's a lot you can do from the users side as well.
11-24-2007, 06:03 PM
If it is 24 and maintaining your temp on low, you should be tickled pink. Sounds a bit oversized to me.
But anyway I was on a call this AM (upper 20s out) where the house wouldn't recover from 65 to 70 degrees after a setback. Gee, it had a Vision Pro IAQ, all the believers in smart thermostats would say you will have no trouble recovering from a setback without backup if you have a good stat. Well, this properly sized system wouldn't recover without backup and the board in the AH wouldn't bring on the strips. So much for that theory.
11-24-2007, 06:15 PM
Was teh IAQ set to lock out the strip heaters?
11-24-2007, 07:31 PM
Nope, IAQ was calling for backup. Board in AH wouldn't bring on backup. Saw evidence of a condensate leak over the summer on the board.
11-25-2007, 06:06 PM
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