Things I learned about heat pumps: a homeowner's perspective

We built our house in 2020-21, right in the middle of the pandemic. We were downsizing as our son prepared to graduate from high school, and we were anxious to keep expenses low over the long term as we age. As a CERTs team member, I wanted to share some of what we learned from making heat pumps our primary heat source in a new build. 

The house is a little over 900 square feet, slab on grade, 2x6 stick-built construction, one main floor with a small loft. It has southeast-facing windows for passive heat in the winter, and blown-in cellulose insulation. (Yes, we know spray-foam is better, but in that particular moment, in our geographic area, the cost difference was just too big for our budget.)

Our home is located in north-central Minnesota.

However, since I’m kind of an energy nerd (and since we wanted to keep our heating and cooling costs low), I was keen on the idea of doing most of our heating with a cold climate air source heat pump.

Because we were not planning on ductwork, we opted for a mini-split configuration. Our general contractor had worked on several projects involving mini-splits before, so he had an HVAC contractor in mind. We deferred to his judgment on that, just specifying that we were specifically looking for an “EnergyStar-certified cold-climate air source heat pump.”

Fortunately, that is what they installed.

It turned out to be a Bryant system with a heating season performance factor (HSPF) of 10.3. For cold-climate models, the HSPF should be greater than 10 (for ductless systems like ours) or 9 (for ducted systems).

There is one outdoor unit that is connected to three indoor heads: a small head in each bedroom and a larger head in the loft to heat and cool the rest of the house. With this being new construction, the line sets connecting the outdoor unit with each indoor head are located inside the walls, not on the exterior of the house (as you would see when adding mini-splits to an existing house).

One nice aspect of ductless heat pump systems: zoned heating and cooling! In other words, I can keep my office space a little warmer than my spouse keeps his, which makes both of us happy.

You know how with a forced air furnace system, you are supposed to change your furnace filter monthly, and get a tune-up each year? It turns out that our mini-split heat pump has similar requirements. 

The indoor air filter should be cleaned monthly (it’s not hard to do - just remove the filter, rinse the dust off at the sink, and dry it before putting it back). The outdoor coil should be cleaned from the outside every six months (also not difficult - just a quick spray with a garden hose) and cleaned by an HVAC tech annually.

So the amount of maintenance is comparable to that recommended for any other heating system.

If you get a heat pump installed, ask your contractor to walk through recommended maintenance with you. We didn’t think to do that, but it would have been nice.

The outdoor unit is mounted on a platform a bit off the ground.

If it’s a really snowy winter, like we had last year, snow can still pile up around it.

When you go out to shovel your walk after it snows, make a practice of checking to be sure your heat pump is clear.