Retrofitting an old house with heat pumps can be an excellent solution when you consider it as an integrated, whole house project.
Our guest blogger Laurie Fielder and her husband Shaun set the stage for their heat pumps in cold climates to be successful by by considering the entire building as an integrated system. Our conversation began at a professional workshop on solar panels which is the most environmentally-responsible way to power electric heat pumps. I’ve heard mixed reviews about heat pump performance in our very cold Vermont winters so I was intrigued to learn more about my colleague’s very positive experience and if they use any auxiliary heat.
It was great to be at the (solar) workshop last week, and I’m happy to tell you a bit about my heat pump experience. We do have a wood stove to supplement/back-up on the very coldest days of the winter, but we are overall very happy with our (heat pump as primary heating) decision. We also did do an extensive energy renovation on our 1962 brick/stud-framed home, which was initially a camp built by a mason on Nelson Pond in Central Vermont, but winterized in the late-1980’s (poorly, though). We bought the home in 2016… needed a ton of work, including a new heating system (was a oil-fired boiler/baseboard system, completely dead).
We did much of the work ourselves–we’ve built and renovated several homes and spaces. We exposed the concrete block foundation, waterproofing and foaming the inside and outside, did lots of fussy airsealing, and replaced every window with Marvin double-pane option (the original camp windows weren’t salvageable or practical for VT winters). Then we hired EnergySmart of Vermont to airseal and insulate the attic and around the massive chimney, and add a high-efficiency bathroom fan in the upstairs bathroom. This was an extensive two-day job for them. Additionally, due to an extreme heat loss from the gable ends (1″ by 10″ rough cut boards with huge gaps so you could see the fiberglass insulation) we removed all the siding from the gable ends, added 2-inch rigid foam, taped the seams, and installed hardiboard siding. We also installed a new woodstove and lined the chimney, and installed a heat pump water heater.
The home is fairly open, and we have two heat separate Fuji CC heat pumps (not a multi-head), one in the basement and one on the main level. We have no heating to speak of on the third floor (two tiny bedrooms and a new bathroom with a dormer and an Envi electric heater that we seldom use), but in the winter, if we turn on the upstairs bathroom fan for about 45 minutes when we get home, the warm air from the main floor makes its way up. We may add a HRV system down the road, but for now, this works. We were motivated to go electric since delivered fuel is a challenge for us on our rural private road. We also wanted to reclaim the floor space that the baseboards took up (they pretty much lined the whole exterior of each room). We find the home to be comfortable in all seasons, and a huge improvement over what we purchased!
Anyway, happy to speak with you more about the project, but you’re right…. heating with heat pumps alone is not for the inexperienced. Both my husband and I are handy and knowledgeable about how homes work in terms of heating, airsealing and insulation. We are also willing to put in the time and labor, and call someone when we need help.
Editor’s note: I took away a couple of lessons from this about heat pumps in cold climates. First, don’t underestimate the value of installing two individual heat pumps rather than a single outdoor condenser with two heads. Secondly, I had never heard of an Envi electric heater— still learning. That led me to this article which does a good job of explaining electric heating.