| Sounds like you gave it an honest try and it wasn't good for your setup - won't argue that. I do think it's something that depends very greatly on your climate, local costs/subsidies, and your house. I also want to shed some light on why heatpumps can be great - by disagreeing with this statement: > you lose ~50% in transmission, and usually it's coming from a coal or natural gas plant Heat pump performance is often rated in terms of COP - a number that indicates how much more heat it generates than the energy it consumes. A COP of 4.0 means that for every Watt of energy, it produces 4 times that much heat. This is thermodynamically possible because a heat pump removes energy (makes cool) the other end. It depends largely on the temperature outside, and the individual device. Follow along with me for some cool results of this: - Natural gas to electricity is about 85% efficient. - Transmission losses are close to 10% - So your house gets (roughly) 75% power efficiency. - Natural gas furnaces are basically 100% efficient (almost all heat from burning goes into your house) - A medium-good heat pump can expect to get a COP of 3.5 on a 30F day With all these assumptions, let's do a little test: - Let's burn a gallon of natural gas in your basement, using 100% of the energy it has. - We get... about 64 BTUs
- Now let's have a power plant burn that gallon and send the electricity to your house at 75% efficiency. - We get 14 Watt hours...
- Now let's put those 14Wh into a heatpump with a COP of 3.5... - We get 167 BTUs!!
That's right - the same gallon of gas burned in a power plant will produce more heat in your house than if you burned it right there. Which sounds basically like magic, but it's of course because a heat pump doesn't create heat, it moves it.Now, whether it makes sense for a given customer has a lot to do with the price of gas, the price of electricity, the price of furnaces vs heat pumps, and the temperature outside (COP can drop down significantly if you live in an extremely cold place). However, if you need an AC, it makes sense to at least get one that can dual function as a heat pump, this way it can be your source of heat in the spring/fall, without having to use the more powerful burner. |