How fast a house loses heat in a winter outage depends on insulation, wind and outdoor cold. Here is what to expect and how to slow it down.
- There is no single number: a tight, insulated house cools far slower than a drafty one.
- The coldest rooms and exterior walls drop first, and wind makes it worse.
- Close off one room, seal drafts and add layers to slow the loss.
People often ask how many hours until the house is too cold. The honest answer is that it depends, so here is what drives it and what you can do.
What sets the speed
- Outdoor temperature and wind: colder and windier means faster loss.
- Insulation and air sealing: newer, tighter homes hold heat longer.
- Size and windows: big rooms and old windows lose more.
- Sun and thermal mass: sunny days and masonry help.
What to expect
The coldest spots are corners, exterior walls and windows, and the basement can stay steadier than upper floors. Check the thermometer, not a guess, and watch for rooms near freezing.
Slow the loss
- Close doors and live in one small room.
- Cover windows with blankets or heavy curtains, seal gaps with towels.
- Use sleeping bags and layers. See heating one room safely.
- Do not burn fuel indoors: carbon monoxide.
Watch the pipes
When rooms near freezing, protect plumbing: guide. If it becomes dangerously cold, go to a warming centre or a friend's home.
Powering heat
A power station can run a furnace fan but not most electric heaters for long: see furnace blower runtime and space heaters.
Backup power picks (Canada)
Size the unit to your own load first: see the sizing guide.
Quick comparison
| Brand | Best for |
|---|---|
| BBLUETTI | Large lineup, expandable home systems |
| JJackery | Wide range, compact to home backup sizes |
Power stations and solar generators with fast charging. Compare capacity and warranty.
Larger capacity power stations that can run a fridge, with expandable batteries.
- Broad capacity range
- Expandable home-backup options
- Compare battery chemistry and stated cycle life
Popular portable power stations and solar kits for short outages.
- Has a Canadian storeHas a US store
- Small, mid and large models
- Compare capacity, output and warranty on the maker page
Quick answers
How long until my house is too cold?
It varies with insulation, wind and outdoor temperature. Use a thermometer.
Which rooms get cold first?
Corners, exterior walls and rooms with big windows.
What helps most?
Living in one small closed room, layers and sealing drafts.