Heat pump water heater—in Maine?
We are nearing the end of construction on our house. We’re on an island in Maine.
The house is 2,400 sq ft., including about 600 s.f. of walk-in basement in one half of the downstairs. (The downstairs walls are ICFs with additional blueboard insulation, 2″ in the basment and 4″ in the finished space. There are 4″ of blueboard under the slab. Upstairs walls are double studs with 11 1/2″ of dense-packed cellulose.)
Our only heat sources are two mini-split heat pumps: one upstairs, one at the opposite end of the downstairs from the basement. We have a 9kW solar array on the roof.
Here’s the conundrum. I had been planning to get a regular electric water heater, installed in the basement because it would be most centrally located to the bathrooms and kitchen. (We have no gas or oil appliances, and propane on an island is crazy expensive.)
I like the idea of a HPWH like the Rheem models, but I didn’t want our water heater and existing heat pumps to be fighting each other in the winter months, when the basement will likely be in the 50s and the heat pump will be working hardest.
However, I do like the idea of a drastically more efficient unit. There is a state rebate of $750 right now on the purchase of any heat pump water heater, which basically makes it the same price as a standard electric model.
So now I’m wondering if I should get the heat pump model, run it in heat pump mode for most of the year, but then switch it to “electric” mode—in which it uses only the electric heating elements—during colder months or if it seems to be cooling the basement too much.
The model I’m most interested in is the Rheem: https://goo.gl/Svos3Z
Am I nuts?