Originally Posted by {OF}G_Man
I'm assuming that you have a heat pump that has a fan coil blower that blows air around/into your house??
A "heat pump" actually defines your basic airconditioning unit, except it only works in one direction. An air conditioning unit pumps heat from the inside of your house in warm weather and rejects the heat outside, the effect is "cooling" for your house air conditioning cooling coil (evaporator). It is a compressor that uses refrigerant to pump "transfer" the heat from inside your house to the outside.
A "heat pump" like you have in your house has a device on it called a reversing valve. It reverses the process of a normal air conditioning unit so that it pumps heat from the outside of your house and rejects it inside, again using refrigerant. The net effect is "heating" from the air blowing across the refrigerant coil (condensing coil).
Even at relatively low outdoor air temperatures there is "heat" in the air, so the compressor pumps that heat back into your house. The compressor also uses electricity, and generates its own heat while running, and this is also transferred through the refrigerant to the heating coil in your house making it more efficient. Heat pumps are very efficient at about 50 F outside air temperature.
One of the characteristics of a traditional home heat pump, is that the colder it gets outside, the less heat it can pump into your house, so the heat pump compressor needs to run longer to keep your house warm, and when it is shut off and starts back up, it takes longer for it to recover. If you set the temperture back too far, it takes a long time to recover, and if you have the auxiliary heating strips like you have to help improve recovery time, you burn alot of electricty trying to catch up. Heat pump systems are designed on the heating side to almost run continuously on cold (design) days to maintain comfort in the house, so don't treat it like a gas furnace. It is designed to run. You will also notice that the air temperature from the heating coil is a lot lower than you will get from a gas furnace, even the real high efficiency gas furnaces. Eventually, when it gets very cold outside, below 37F, the heat pump system reaches it's balance point, and that is when it runs continuously to maintain your house temperature. Once it gets below the balance point, the supplemental electrical heating will kick in anyway since the heat pump will not be able to keep up. At this point about the only choice is to lower you house temperature to where you can stand it, to help reduce the use of the expensive supplemental electrical heating. For this reason, the further north you go, the fewer heat pumps you will find, especially the residential type, unless they are the water source type. I've known people here in Michigan that have had the air source heat pumps systems installed, and had such problems in cold weather, that they ripped them out and put in a standard gas furnace.
My advice in the winter is to set your thermostat where you want it, and let it run, but on the coldest days you may still see the booster heater strips come on and lowering your thermostat then would help save some bucks. The programmable thermostat would be great for the air conditioning cycle, but I wouldn't use it much on the heating side, unless you use it for smaller setpoint changes.
And BTW any supplemental electric heating device will be expensive if you use it much.
The unit you are looking at for you basement is 1500W = 1.5KW = 1.5KW hours each hour it runs. How much do you pay per KW hour?
If your system design can support it, many people are now "zoning" their houses both with gas fired furnaces and heat pumps. A motorized damper is put in a couple of branch ducts, like one going upstairs and one going downstairs. Two thermostats are used. One in upstaris and downstairs as an example. If the downstaris thermostat "calls" for heat, and the upstairs thermostat isn't, the upstairs damper is closed, the downstairs damper is opened and all the warm air is directed downstairs where it is needed. A local reputable heating company could evaluate your system and install this type of solution if you are interested. That's where I would spend my money if it can be done.
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