Home Electrification Part Two - Upstairs Heat Pumps

Upstairs Heat Pumps

My wife loves open floor plans. She had her sights set on removing the wall between the kitchen and living room ever since we moved into our house last fall. The wall is load bearing and so we hired a structural engineer to help us determine the best beam and column combination. The wall also contains the supply and return ductwork to three of the upstairs bedrooms. Alternative duct routes would have required bulky bump-outs in the walls. We could have put a second furnace/heat pump in the attic, but it is a low attic and I did not want to climb up there to change filters.

Thermal image shows heating ducts in living room wall.

We decided on mini-split heat pumps. Each of the four upstairs bedrooms would have its own 1/2 ton head, all connected to a 2 ton outdoor heat pump. A benefit of this system is that each bedroom would have its own controls. Typical of two-story colonials, the upstairs bedrooms were uncomfortably warm this summer. The upstairs temperature was consistently 4° to 5° F warmer than the first floor. In the new system, each room can be set to its own cooling set point.

The aesthetics of wall mounted mini-splits are not popular in the US. I selected a ceiling recessed indoor model. As you can see in the photo below, the unit is mostly in the attic with a face plate and grille on the ceiling. Filter cleaning is performed by taking off the face plate. No need to go in the attic.

One-way cassette indoor unit in my daughter's bedroom

I coordinate the installation with an attic insulating and air sealing project so there was no insulation in the attic when the contractors installed the units. They built housings out of rigid insulation boards to go around the units in attic and caulked them air tight. This keeps the cellulose insulation from falling out when the face plate is removed and helps air seal the attic.

New 2-ton heat pump outdoor unit.

I am excited to finally have a heat pump system at my house. Despite some sub-zero nights in December, the upstairs has stayed comfortable and warm. I am excited for how much cooler the bedrooms will be in summer. Next up is the kitchen remodel.

The heat pumps was working away in freezing temperatures.