Heat Pump Installation in Seattle, WA
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Ten months of heat, mild summers, King County asks something specific of a heat pump
Winter nights here average 32°F from December through February. Summer afternoons average 70°F. That is not a hot climate. A heat pump installed here spends almost all its time heating, not cooling, and it needs to keep working on those 32°F nights without leaning on backup heat too often.
Homes in King County need heat or cooling ten months of the year, September through June, and none of those months call for cooling alone. Any split-system heat pump installed new has to meet the federal minimum of 14.3 SEER2 for cooling and 7.5 HSPF2 for heating, but in a climate like this, the heating side of that rating matters more than the cooling side ever will.
- 10 months
- September through June, your system heats
- 32°F
- the average winter night it heats against
- 70°F
- the average summer afternoon it cools against
Washington requires contractors to register with the state.
Registration means the contractor's business is on file with the Department of Labor and Industries. There is no trade exam attached to it. It tells you the business is real and on record, not that anyone checked their skill at installing a heat pump.
For this job, the check that matters most happens locally. In most cities and counties, replacing a heat pump needs a permit from the building office and an inspection once the work is done. That inspection is what confirms the unit was installed correctly. The state registration does not cover that.
Source: Washington State Legislature
- Is a heat pump better than a furnace?
- For Seattle, most homeowners come out ahead with a heat pump. It heats and cools from one system, and it moves heat instead of burning fuel to make it, so it uses less energy to produce the same warmth. Winters here average a low of 32°F, which a heat pump can handle without leaning hard on backup heat. A furnace only heats, so you would still need a separate system for summer, even with afternoons here averaging just 70°F.
- What's the difference between a heat pump and an air conditioner?
- An air conditioner only cools. A heat pump cools the same way in summer, but it can also run in reverse and pull heat from the outside air into your home in winter. Mechanically they share the same compressor and coils, the difference is the reversing valve that lets a heat pump switch direction. Homes in Seattle need heat from September through June, so that reversing valve gets used most of the year here.
- Does a heat pump work in cold weather?
- Yes, a heat pump keeps working in cold weather, though it pulls less heat from the air as the temperature drops. Seattle's winter nights average around 32°F, which is well within the range a properly sized heat pump handles on its own. Below a certain outdoor temperature, output drops enough that some systems add electric resistance heat or another backup source to keep up. A contractor sizing the system for your house will know at what temperature that backup should kick in.