View Full Version : Heat pump power

03-04-2009, 04:20 PM

I was recently thinking about replacing my standard central heating with something less conventional like heat pump. My house is about 200m2 and I don't know how much power I would need to heat it in the winter. As far as I know, there are heat pumps from 10kW to 35kW ( solarusmax.com/pompyciepla.php ). Thank you in advance for any answer.

03-04-2009, 06:44 PM
You need someone to do house heat loss calculation.

14-04-2009, 08:58 PM
Before you retrofit to a heat pump, there are a few things to consider, especially if you have long cold winters. First, heat pumps are not as efficient as a condensing gas furnace, which has a COP of nearly 1, even when the outdoor temperature is well below freezing. Electric heat pumps have a COP of 3 or more, but that is at 47 F, and is the ratio of btuh out to site btuh (site electric power) in. The actual efficiency is about 3.5 times less than 3, or less than 1, especially if the temperature is only 17 F. At 17F most heat pumps have a COP of about 2, or a fuel efficiency of .57. This is because the power plant supplying the electric power is much less efficient than a local furnace – usually only 30% or so. That’s why the cost of electricity per million Btu is generally about 3 times the cost of fossil fuel.

Second, heat pumps don’t generate much hot air. Since they are usually also summer cooling machines, the airflow across the coil is high relative to a furnace, so for a given capacity, heat pumps circulate colder air – on the order of 80 – 85 F – than furnaces which deliver nice warm air at 95 – 120 F. Also, the colder it gets, the more dependent on the “auxiliary” electric heat. That can warm the air, but at the expense of COP.

I live in Florida, and mostly specifiy heat pumps for my clients. If I practiced in Austria, I don’t think I would recommend heat pumps.

26-04-2009, 10:07 PM
It depends on the region you live in. Heat pumps will give good heat until the osa drops below 35F to 33F anything below this will cost you electricity for strip heating. It does have it's advantages in tropic areas or in areas (rural) where no NG gas is available.