Heat pumps and mini splits in Birchwood

The houses in Birchwood

Birchwood is Bellingham’s postwar rambler belt — single-storey three-bedroom houses, hip roofs, attached single-car garages, laid out on a regular grid north of Squalicum Creek. Almost all of them sit over a low crawlspace rather than a basement, with the furnace either in a hall closet or out in the garage. Along Northwest Avenue and Birchwood Avenue there is a second layer of 1970s walk-up apartments and duplexes.

What is probably heating yours right now

The owner-occupied ramblers are mostly on gas furnaces, and a good share of those are second- or third-generation replacements sitting on top of the original crawlspace duct runs. The rentals and the walk-ups are typically electric: baseboard in the bedrooms, a wall heater in the hall. Where a Birchwood house never got gas service, an electric furnace or full baseboard is common, and that is the case PSE’s $1,500 conversion rebate was written for.

What makes a Birchwood install different

The crawlspaces are the whole story in Birchwood. They are shallow — often under two feet of working height — with the original sheet-metal trunk hung tight to the joists and flex runs that were never sealed, so a heat pump moving more air than the old furnace will find every leak. We measure static pressure before we quote, and we would rather seal and resize the trunk than sell you a unit that can never reach its rated capacity. Outdoor unit placement is easy: side yards are wide enough for a proper pad and a short lineset to the garage or hall closet.

Sizing for 19°F

Every Bellingham address shares the same code design temperature — 19°F at station Bellingham 2 N, colder than Sea-Tac's 24°F. What differs street to street is the envelope. A 1910s one-and-a-half storey with knee walls and original single glazing carries a very different load from a mid-2000s two-storey built to a modern code, even at identical square footage. That is why we run the load rather than multiplying square feet by a constant.

We know the streets

If you are near Birchwood Park, Squalicum Creek Park, the Northwest Avenue corridor, we have worked nearby. Ask and we will tell you honestly what we have run into on that side of town.