Heat pumps and mini splits in Lettered Streets

The houses in Lettered Streets

The Lettered Streets are Bellingham at its oldest: one-and-a-half-storey cottages and modest Victorians on the grid of A through I streets north of downtown, most of them built for people working the waterfront. Upstairs rooms sit under the roof slope with knee walls and dormers, so there is very little chase space and no attic worth the name. Basements are shallow and often only partly excavated, lots are small, and nearly every block has a working alley behind it.

What is probably heating yours right now

You find everything from a 1950s gas conversion still breathing through the original oversized gravity trunk, to baseboard added room by room as owners gave up on the ducts, to a wall heater doing the whole ground floor of a small cottage. A large share of these houses are rentals with electric resistance heat throughout, which is precisely the existing system PSE’s $1,500 conversion rebate is written for. Insulation is typically original, so a load calculation here needs to reflect the envelope you actually have.

What makes a Lettered Streets install different

Electrical capacity is the first question in the Lettered Streets. Plenty of these houses still have a 100-amp service — some less — and a ducted heat pump with any resistance backup will not fit on it, so a service upgrade by a licensed electrical contractor has to be priced as part of the project rather than discovered on install day. The upside is alley access: we can bring equipment in from the back and set the condenser away from the street elevation, which matters on blocks where the streetscape is the neighborhood’s whole appeal. For the half-storey upstairs, a ductless head is nearly always the right answer over trying to force a duct through a knee wall.

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 Broadway Park, the Old Town brick storefronts on West Holly, Squalicum Harbour, we have worked nearby. Ask and we will tell you honestly what we have run into on that side of town.