Generators, Dehumidifiers and Carbon Monoxide Safety During Cleanup

Why Carbon Monoxide Kills During Cleanup

Carbon monoxide, or CO, is a gas you cannot see, smell or taste. Every gasoline engine makes a lot of it. A small portable generator can put out as much CO as many running cars. Indoors, CO can build to deadly levels within minutes, and it can seep into a home from a generator running just outside an open window or door.

CO poisoning is a well known cause of death after storms and power outages, and it often happens to people who thought they had enough air flow. Opening a garage door, a window or running a fan does not make it safe.

Early symptoms feel like the flu without a fever.

• Headache
• Dizziness or weakness
• Nausea or vomiting
• Chest pain
• Confusion

People who are asleep or drinking can die before they notice anything. Pets often get sick first. If anyone has these symptoms or a CO alarm sounds, get everyone outside into fresh air right away and call 911. Do not go back in until the fire department says the air is safe.

Where to Put the Generator

The single most important choice is where the generator sits.

• Outdoors only. Never inside a home, garage, basement, crawlspace, shed, carport or on a covered porch, even with doors and windows open.
• At least 20 feet from the home. Federal health guidance uses 20 feet as a minimum. Some manufacturers list a greater distance, and you should follow whichever is farther.
• Exhaust pointed away from doors, windows, vents, air conditioner intakes and your neighbors’ homes.
• On a flat, dry surface where water cannot pool.
• Under an open sided canopy or a generator tent rated for that unit if it is raining. Never enclose it in a box or under a tarp that traps exhaust.

Newer portable generators often have an automatic CO shutoff that turns the engine off if CO builds up around it. That feature is worth paying for, but it does not replace distance or CO alarms inside the home.

Carbon Monoxide Alarms

CO alarms are your backup if exhaust finds a way inside. They are cheap and they save lives.

• Put a CO alarm on every level of the home and outside each sleeping area.
• During an outage, use battery powered or battery backup alarms. Plug in alarms with no battery stop working when the power is out.
• Test alarms before you start the generator. Replace batteries if you are unsure.
• Most CO alarms need replacing every 5 to 10 years. Check the date on the back.

A smoke alarm is not a CO alarm unless it says it detects both. If you have fuel burning appliances, an attached garage, or you are running any engine near the home, CO alarms are not optional.

If an alarm goes off, do not look for the source first. Get everyone out, then call 911 from outside.

Other Engines That Make CO

Generators get the attention, but other cleanup tools are just as dangerous in closed spaces.

Never use a gas oven or stovetop to heat a home. If you need to pump out a basement, the pump motor stays outside or you use an electric submersible pump powered by the generator.

Cords, Loads and Backfeeding

Plug drying equipment directly into the generator with heavy duty, outdoor rated extension cords. Use 12 gauge cords for longer runs or bigger loads. Check that cords have no cuts or missing ground pins and keep connections off wet ground.

Never plug a generator into a wall outlet or dryer outlet to power the house. This is called backfeeding. It can send power back through the utility lines and electrocute line workers or neighbors, and it can start fires in your home. The only safe way to power house circuits is a transfer switch or an interlock kit with an inlet, installed by a licensed electrician.

Know your limits before you plug in.

• Add up the running watts of everything you plan to use and stay under the generator’s rated running watts.
• A home dehumidifier often uses roughly 300 to 700 watts. A box fan uses about 50 to 100. Commercial air movers and dehumidifiers can use much more, so check the label.
• On house circuits once power returns, a standard 15 amp circuit should carry no more than about 1,440 watts of steady load, and a 20 amp circuit about 1,920 watts. Spread equipment across circuits.

Running Dehumidifiers and Fans Safely

Drying equipment runs for days, often while you sleep, so set it up with care.

• Plug into ground fault protected outlets, or use a portable GFCI adapter, anywhere near water.
• Do not daisy chain power strips or extension cords. Plug each heavy load into its own cord or outlet.
• Run the dehumidifier drain hose to a floor drain, sink or sump so it can run nonstop. A full bucket shuts it off.
• Keep the room closed while the dehumidifier runs so it is not trying to dry the outdoors.
• Check cords and plugs every few hours. A warm plug or cord is overloaded. Unplug it and move the load.
• Keep fans and cords away from standing water, and never run equipment in a room with water on the floor that could reach the plugs.

Most home dehumidifiers work best in warm rooms and slow down below about 65 degrees Fahrenheit. In a cold basement, a pro grade dehumidifier may be needed.

Fuel and Refueling

Gasoline vapor is heavier than air and can travel along the ground to an ignition source.

• Turn the generator off and let it cool for several minutes before refueling. Fuel spilled on a hot engine can ignite.
• Store fuel in approved containers, outside the living space, away from the generator and any flame or pilot light.
• Do not store gasoline in the home or basement.
• Buy fuel before a storm if one is forecast, because stations may lose power too.
• Use fresh fuel. Old gasoline can make a generator stall or fail to start.

Never run a generator in the rain without cover, and never touch it with wet hands. Dry your hands before you plug or unplug cords.

Step by Step

1. Check Your CO Alarms

   Put battery powered or battery backup CO alarms on every level and outside bedrooms. Test them before starting any engine.

2. Pick the Spot

   Place the generator outdoors on dry, level ground at least 20 feet from the home, or farther if the manual says so.

3. Aim the Exhaust

   Point the exhaust away from doors, windows, vents, AC units and neighbors’ homes.

4. Cover It Safely

   If it is raining, use an open sided canopy or a generator tent made for the unit. Never enclose it.

5. Run Cords Directly

   Plug equipment straight into the generator with heavy duty outdoor rated cords. Never connect it to a wall outlet.

6. Add Up the Load

   Total the running watts of fans and dehumidifiers and stay under the generator’s rated running watts.

7. Set Up Drying Gear

   Use GFCI protection, give each big load its own cord, and run dehumidifier drain hoses to a drain.

8. Refuel When Cool

   Shut the generator off and let it cool before adding fuel. Store gasoline outside the home.

9. Know the Warning Signs

   If anyone has a headache, dizziness, nausea or confusion, or an alarm sounds, get everyone outside and call 911.

Mistakes That Make It Worse

• Running a generator in the garage with the door open. CO can still reach deadly levels and seep into the home.
• Setting the generator right next to an open window or door. Exhaust drifts straight inside.
• Plugging a generator into a dryer outlet to power the house. Backfeeding can kill utility workers and start fires.
• Relying on plug in CO alarms during an outage. Without a battery they do nothing when the power is out.
• Daisy chaining power strips to run air movers. Overloaded strips and cords overheat and start fires.

Where You Live Matters