3 ms·
Talking about capacity for heat pumps is tricky, their available heating power changes continuously as a function of outdoor temperature. The convention is to r
by cmui 4y ago
Talking about capacity for heat pumps is tricky, their available heating power changes continuously as a function of outdoor temperature. The convention is to refer to the available capacity at 47F for 'normal' heat pump and the capacity at 5F for a cold climate heat pump.
- sosodev 4y agoMakes sense. How much does their capacity typically change over their operating temperature range?
- malfist 4y agoHeat pumps extract heat, either from the house, or from the outside air. When heating, it pulls it from the outside air. As it gets colder, there is less heat to pull out. Typically heat pumps will still keep pulling heat at >100% efficiency nearly into the negatives, but the amount they're extracting isn't enough to keep up with the heat loss of the house. Heat lost of the house is a factor of insulation, surface area and heat gradient. It's a lot harder to keep a house at 68F when it's 5F outside than it is when it is 50F. So when it's cold out, you need more heat generation, and there's less heat to pull from the air. That's why heat pumps have backup auxiliary heat.