Not that simple.
Your evap will freeze before you drop the RH [when lowering the blower speed on a unit that is over sized]
So I am still confused. HP advantage is the compresser draws less amps for less $$$ than the heat strips. But in really cold areas would it not be cheaper to use LP, oil or whatever else ya"ll use. I am not tring to be critical I have just been told HP are for mild climates and don't work well below freezing. They just cost so much more than a reg unit and I don't see the advatage. some please give me a good argument
Actually, a heat pump puts out 2 or 3 times more heat than it consumes in electricity even well below freezing. This is true because the electricity is used to move heat contained in outdoor air and move it indoor. An electric coil converts electricity into heat directly.
Electricity is MUCH cheaper than gas or fuel oil. Not to mention oil is old fashioned and dirty and rarely seen in new installations.
I disagree I have a gas unit and my bill is like 50 bucks at most. This includes dryer, oven, and stove. Plus it is just a better heat. I understand if you don't have Nat gas as an option, I just fig that far north you guys would have better options
Electricity here is half the price than in, for example, Miami or 3.5 times less than New York.
Back in the 1960's we saw the future and built huge hydro-electric installations way the hell up north - this is infinitely renewable and therefore relatively cheap for us.
That sounds like a lot to me. My electric bill last month, including quite a few nights below freezing, was $75 including Tampa Electric's rate hike. All-electric house. So that's heating & cooling, water heating, washer/dryer/stove/oven and electronics, with electronics consuming most of it.
Originally Posted by crowemagnum
There's a huge difference between using energy to move heat (heat pump) vs. converting the energy to heat (fossil fuel). Heat pumps run 200-300% efficient for heat delivered vs. energy consumed. You'll never be able to do that by burning fossil fuels at home for heat. Maybe some day the manufacturers will come up with a gas/oil-driven heat pump in residential sizes, but I won't hold my breath. US manufacturers are still decades behind the rest of the world.
Heat is heat. 1 BTU = 1 BTU no matter how you slice it. Define "better heat." I personally prefer even, consistent temperatures. I don't want to hear it running nor feel it running. I'd like to be able to set/program it and that be the end of it. Much like the electrical distribution system of my house. Essential, and certainly far more complex than the average house, but totally hidden once it's installed.
Plus it is just a better heat.
Also keep in mind that, for us at least, electricity is provided by hydro electric installations. This means nothing is burned and no greenhouse gas is produced - much better for the environment.
As for the installation at home, I would say it is a bit more robust than elsewhere in North America. For instance, we have a 400 amp service to run two separate heat pumps each with 15,000 watts of auxiliary electric coils.
[QUOTE=KrisAMS;2400072]Actually, a heat pump puts out 2 or 3 times more heat than it consumes in electricity even well below freezing.
Could you give some Data on this or is this a SWAG?
If you help others then you are a Success
If you help others then you are a Success
At 10C, the coefficient of performance (COP) for air-source heat pumps is typically about 3. This means that 3 kWh of heat are transferred for every kWh of electricity supplied to the heat pump. At -8.3C, the COP is typically two.
The COP decreases with temperature because it is more difficult to extract heat from cooler air. Figure 5 shows how the COP is affected by cooler air temperature. Note, however, that the heat pump compares favorably with electric resistance heating (COP of 1.0) even when the temperature falls to -15C.
You may be able to reduce your heating costs up to 50 percent if you convert an electric furnace to an all electric air-source heat pump. Your actual savings will vary, depending on factors such as local climate, the efficiency of your current heating system, the cost of fuel and electricity, and the size and HSPF of the heat pump installed.
More advanced designs of air-source heat pumps are able to provide domestic water heating. Such systems are called "integrated" units because heating of domestic water has been integrated with a house space-conditioning system. Hot-water heating can be provided with high-efficiency in this way. Water heating bills can be reduced by 25 to 50 percent.
OK I asked around today. I am being told that a heat pump is most eff at 40-45 degree's and your chart seems to suport this with the balance point being at 30. So to me this means that if you live in a climate that has an avg below that during the winter you should not have a HP. Even if it is still more eff than just heat strips the major extra cost of the units would take years to recover. We should probaly start a new thread somewere else seeing how we have hijacked this thread. might put it up later with one to argue better heat Gas vs eletric
I don't think this is correct. At -8.3C, the COP is typically two. In other words, even at -8c the HP is 200% efficient. The Government goes on further to state that heat pumps are still better than electric until -15c.
This is only half the story because it is not the same temperature every day! In the Autume the temperature gradually falls and in the Spring it gradually rises. The temperature in Winter can change drastically from day to day as well.
Considering you tend not to move every year or two, the extra cost will be minuscule compared to the savings. This is clearly stated in the Government document I posted below.
that's a light dusting compared to some of the systems that freeze up round' here
least your OD fan motor was still turning