HVAC Installation in Seattle, WA
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Ten months of heat a year in King County
Winter nights here average 32°F from December through February, mild as far as furnaces go. What matters more is how long the season runs. Homes in King County need heat from September through June, ten months out of the year. A new system spends most of its life working, not sitting idle, so it has to be sized and installed for that kind of run time.
Cooling barely enters into it. Summer afternoons average around 70°F, too mild for most homes to need air conditioning at all. If you are adding cooling, it is for the occasional warm day rather than a real summer. More than half the homes here heat with electricity, and with 23% of Washington households losing power for at least a day in 2024, how a new system handles an outage is worth asking about before it goes in.
- 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.
That registration puts the business on file with the Department of Labor and Industries. It does not mean anyone tested the contractor's work. There is no trade exam behind it, so it is a record, not a credential.
For an install like this, the protection comes from elsewhere. In most cities and counties, replacing a furnace, air conditioner or heat pump needs a permit from the local building office, with an inspection when the work is done. That inspection is what checks the gas and electrical connections and confirms the system was put in correctly.
Source: Washington State Legislature
- When should I replace my HVAC system?
- Replace it when repairs start costing more than they save you, or when the equipment keeps failing in the same spots. A furnace that's short cycling, an air conditioner low on refrigerant, or a system that can't keep the house warm on the coldest nights are signs the equipment is done, not just due for a repair. Homes here need heat from September through June, so a furnace running that many months a year sees more wear than one running just a few. If a contractor is out at your place more than once a season, that's usually the point to start pricing a replacement instead of another fix.
- Should I replace my furnace and air conditioner at the same time?
- If they were installed together and one is failing from age, it often makes sense to do both, since the other is usually close behind. A furnace and air conditioner installed at the same time tend to wear out around the same time too. Homes here need heat most of the year, so the furnace carries the heavier load between the two. A contractor can look at the age and condition of each unit and tell you honestly whether replacing both now makes sense or whether the second one has years left.
- What happens during an HVAC installation?
- A contractor removes the old equipment, sets the new furnace, air conditioner or heat pump in place, and connects it to your ducts, gas line or refrigerant lines and electrical circuits. Once it's hooked up, they test it, checking airflow, gas pressure or refrigerant charge depending on what was installed. This job needs a permit from the local building office, and an inspector checks the work once it's finished. That inspection confirms the installation was done to code, which matters for safety and for anything under warranty later.