Heat waves
Keeping one room cool through a run of very hot days.
Keeping one room cool
An air conditioner sized for one room is the main defence: Health Canada suggests turning it on before it gets hot and keeping one cool room you can go to for relief. In extreme heat a fan isn’t enough.
An air conditioner for one room
If your window takes one, a window unit sits half outside, so less heat comes back in. Where one won’t fit, a portable cools the room; a dual-hose or hose-in-hose model pulls less warm air in than a single-hose one.
You can do this yourself
Our pick
Midea Duo 12,000 BTU DOE Smart Inverter Portable Air Conditioner
Inverter portable with a hose-in-hose duct; kit fits 19 to 64 in windows
Central air or heat pump service
Have air conditioning repaired or installed before a heat wave.
Needs a heating and cooling contractor
Heating and cooling emergencies
Furnace and boiler repairs · Heat pump and AC service · Frozen pipes
The plan
Cool one room before the heat arrives
Turn the air conditioner on before it gets hot, and keep one cool room you can go to for relief.
Know where you’ll go if it gets too hot
With no air conditioning, spend a few hours somewhere that has it, such as a library or mall.
Check on others
Older neighbours and anyone living alone are most at risk.
Safety: Fans don’t cool the body above 35 °C, Health Canada says. Call 911 for signs of heat stroke.
Find a heating and cooling contractor
Pick the job, then your city.
We don’t store what you type.
Questions about heat waves
Window unit or portable air conditioner?
A window unit if your window takes one: it sits half outside, so less heat comes back in. A portable suits sliding or casement windows and renters. If you choose a portable, a dual-hose or hose-in-hose model pulls less warm air into the room than a single-hose one.
How should I use an air conditioner in a heat wave?
Health Canada suggests turning it on before it gets hot, and with a window unit cooling one room you can go to for relief. If you have no air conditioning, spend a few hours somewhere that does, such as a library or mall.
Is a fan a substitute for air conditioning?
Not in extreme heat. Health Canada says fans don’t cool the body at temperatures above 35 °C, though they can make you feel more comfortable below that. Check on older neighbours and anyone living alone.
How big an air conditioner do I need?
Compare the DOE figure: the cooling capacity (SACC) on the EnergyGuide label, not the bigger ASHRAE BTU number on the box, which is measured differently. Our pick, the Midea Duo, is 12,000 BTU on its EnergyGuide label and Midea rates it for rooms up to 550 sq ft.
Will a portable air conditioner fit my window?
Measure the window’s width and height first, and note whether it slides up or sideways. The Midea Duo’s kit covers openings from 19.1 to 63.8 in, with adapters for sliding windows, Midea’s manual says; a narrow window may need one adapter shortened.
Can I run an air conditioner on an extension cord?
Plug it into a wall outlet on a circuit without other big loads. Midea’s manual for the Duo says not to lengthen the cord or use an extension cord, and not to share the outlet with other appliances.
Who is most at risk in a heat wave?
Older neighbours and anyone living alone. Health Canada asks people to check on them, and to call 911 for signs of heat stroke.
