Winter
What the coldest night asks of a heat pump.
Heat pumps do not stop working at freezing. They deliver less as the air gets colder, and that is a sizing question we answer on paper before you buy.
The outdoor unit pulls heat from air that still holds some, even well below zero. A cold-climate model keeps doing that at temperatures that stall an ordinary one. Efficiency Maine says many cold-climate units perform down to -22 degrees F.
The manufacturer publishes how much heat each model delivers at several outdoor temperatures. We compare that table with your house's heat loss on a design day, which is the cold night the equipment must cover. If it falls short, we choose a bigger model, add a unit, or plan the backup. You see the comparison on the quote.
The calendar
A year with a heat pump in Maine.
What we do, and what you do, through the seasons. Dates shift with the weather.
- Sept–Oct
Early fall
We book installs and commissioning. You choose whether the boiler stays for the first winter.
- Nov
First hard freeze
We check that your backup thermostat settings are doing what we set them to do. You note which rooms run cold.
- Dec–Mar
Deep winter
You keep a path clear around the outdoor unit after storms. Call us if it ices over and does not clear.
- Apr–May
Spring
Yearly service: filters, coils, condensate drain and outdoor unit clearance.
Reading the numbers
What the quote shows about winter.
What it means
The system covers the house on that night
Compared with your house's heat loss
Set on the thermostats at commissioning
Above where drifts and roof runoff land
On your quote
The cold night we size for
Heat the model delivers at that temperature
Which system runs if the heat pump falls behind
Wall bracket or raised stand
Winter questions.
Do heat pumps work through a Maine winter?
Cold-climate models do. They are built to keep heating well below freezing, and Efficiency Maine says many perform down to -22 degrees F. What matters for your house is the equipment's published output at your coldest design temperature, so we size from that number and not from the model's name.
What happens on the coldest nights?
The outdoor unit delivers less heat as the air gets colder. A system sized from a load calculation covers the house on the design day. If you keep your boiler or furnace as backup, it takes over only if the heat pump falls behind, and we set the thermostats so you can see which one is running.
Does snow bury the outdoor unit?
We mount outdoor units on a wall bracket or a raised stand, above where drifts and roof runoff land. Keep a path clear around it after a storm. A little steam or frost on the unit in winter is normal; it is the unit clearing its own coil.
What if the power goes out?
A heat pump needs power to run, and so does an oil or propane burner. If outages worry you, ask us about a generator or battery connection when we plan the electrical work.
See what your house needs.
Book a home visit and we will bring the numbers for your house.