I just signed up for an air source heat pump to replace my Boilermate hot water heater. I understand the basics of how it works, but I'm concerned at how much cooler my basement will be when the heat pump is running in the winter. It's a 50 gallon heat pump. The basement volume is 5000 cubic feet. I live in Massachusetts. Can anyone give me some guidance? I tried to do some basic heat transfer calculations (I'm a retired mechanical engineer), and the calculated drop in air temperature is kind of scary.