How to run a generator without carbon monoxide risk
Carbon monoxide has no smell, no colour and kills in minutes. Where a generator can go, where it never can, and why an open garage does not count.
Every storm season brings deaths from generator poisoning, and almost always in the same situation: inside a garage with the door open, because it seemed ventilated enough.
Where it can go and where it cannot
| Location | Acceptable? |
|---|---|
| Outdoors, 20 ft from openings, exhaust pointing away | Yes |
| Garage with the door open | No |
| Basement, shed or utility room | No |
| Under a covered porch or eave | No |
| Next to an open window | No |
| Covered balcony or terrace | No |
Why you need a detector
Carbon monoxide has no colour and no smell. There is no way to notice it until symptoms appear, and those symptoms — headache, dizziness, nausea, weakness, confusion — look a great deal like what you would expect after two days without power and poor sleep.
A battery detector inside the house, near sleeping areas, is what turns a silent poisoning into an alarm. Plug-in units are useless during an outage.
If the alarm sounds: everyone outside immediately and call emergency services from outdoors. Do not go back in to ventilate.
The generator’s other two risks
Backfeeding the grid. Plugging a generator into a house outlet sends current out to the utility lines and can electrocute the crews repairing them. Connecting to house circuits is done with a transfer switch installed by a professional.
Fuel. Store it in approved containers, outside the house, and never refuel with the engine hot or running.
Overload and cords
- Calculate the load first: stacking appliances until the generator bogs down is how equipment gets damaged and cords overheat.
- Use heavy-gauge outdoor extension cords in good condition.
- Do not run cords under rugs or through doorways that crush them.
- Plug appliances directly into the generator, not through daisy-chained strips.
- How long food lasts in the fridge without power Four hours with the door closed and up to 48 in a full freezer. What survives, what gets thrown out, and why smell is not how you decide.
- What to do if you depend on electrically powered medical equipment CPAP, oxygen concentrators, pumps and refrigerated medication. How to size the backup you need and which registrations to set up in advance.
Gear that covers this
Products that match what the guide above recommends.
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Battery carbon monoxide detector
The only way to know there is carbon monoxide before symptoms appear. Battery powered, because plug-in units do not work during an outage.
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Portable power station
No exhaust, so it runs indoors. For moderate loads it removes the risk entirely.
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Heavy-gauge outdoor extension cords
Let you keep the generator far away and bring the power in. A thin cord heats up and becomes a fire risk.
Frequently asked questions
How far from the house does a generator need to be?
At least 20 feet from doors, windows and vents, outdoors, with the exhaust pointing away from the building.
Can I put the generator in the garage with the door open?
No. A garage with the door open still accumulates carbon monoxide to lethal levels. It is one of the situations that causes the most deaths every storm season.
How do you detect carbon monoxide?
Only with a detector. It is a colourless, odourless gas, and the first symptoms — headache, dizziness, nausea, confusion — are easily mistaken for the exhaustion of the emergency itself.
Can I plug a generator into a wall outlet?
No. Backfeeding a generator into house wiring can electrocute the crews repairing the grid. Connecting to house circuits requires a transfer switch installed by a professional.