# Exhausting generator through garage wall?



## Trashman42 (Oct 28, 2012)

Got a portable generator that sits in my garage. During events like hurricane Sandy, I don't want to park it outside while it's pouring rain and try to refuel in the rain. Also don't like all the electrical outlets exposed to the rain. Would like to keep it running inside the garage during rain and snow where it's nice and dry. The concern is the engine exhaust. I'd like to use flexible exhaust tubing to extend the exhaust pipe through the garage wall, but the pipe will get very hot. How can I insulate the garage wall from the effects of a hot exhaust pipe?


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## gregzoll (Dec 25, 2006)

You shouldn't. Just chain it outside for safety, and when you go to fill it after shutting it down, pour in the fuel, while having someone either hold a umbrella, or just get wet.


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## sublime2 (Mar 21, 2012)

Put the generator as far away from garage door as u can,run the pipe under the door.
By the time the exhaust reaches the pipe it probably won't be that hot.
Cutting a hole will require sealing the hole from the heat and the elements.


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## joecaption (Nov 30, 2011)

There's been many a person killed from the carbon monoxide and garages burned down from trying this.


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## sublime2 (Mar 21, 2012)

There's also been many of persons who lived to learn another day.


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## AtlanticWBConst. (May 12, 2006)

Previous Discussion on same topic here:

http://www.diychatroom.com/f18/running-generator-garage-27244/


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## smalpierre (Mar 1, 2012)

At the car shop I worked at years ago there was a 4" round door fitting for a flexible pipe to go through. We would slip one end of the hose over the exhaust pipe as far as it would go, and the other went through the hole. The path of least resistance was out the door rather than bypassing into the shop - so even though it was slip fit over the pipe, it would vent to the outside.

We weren't running them constantly in the shop though, and enough bypassed to make the shop reek.

If your garage is detached, I'd say no problem. If it's attached, you've got some serious considerations. Is the door to the house a well sealed exterior door? Are there any penetrations into the attic cavity? Is the area well ventilated?

If you've got an exterior door between the house and garage, no penetrations (attic stairways, recessed lighting, etc) into the attic, and you seal any other penetrations between areas - electrical boxes (including ceiling lights), plumbing penetrations, good drywall joinery, AND you have very good ventilation in the garage (crack 2 opposing windows?) - AND you vent the exhaust to the outside, you might be good - but I wouldn't bet the ranch on it.


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## Jim F (Mar 4, 2010)

Do people generally run these things in the rain? I'm new to generators. Never needed one till recently.


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## md2lgyk (Jan 6, 2009)

Jim F said:


> Do people generally run these things in the rain? I new to generators. Never needed one till recently.


No, portable generators should not be operated in the rain. They should be under a covered porch or otherwise protected. And despite some of the advice here, they should never under any circumstances be operated inside a garage or other building.


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## gregzoll (Dec 25, 2006)

Jim F said:


> Do people generally run these things in the rain? I new to generators. Never needed one till recently.


Done that way all of the tume in an emergency. The life expectancy is not as long as most people have them for.


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## Wildie (Jul 23, 2008)

I used to run mine in a garden shed. The shed had a power feed from the house and I back fed from the generator.

I cut a 3" circular hole in the door, covered this with a sheet of aluminum flat stock. Then I cut a hole for the exhaust pipe to fit through. This kept the hot pipe removed from the wood in the door!

To run a gas fired generator in an attached garage would be suicidal!


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