# Generator in Garage



## firedawgy (Nov 14, 2019)

I know this issue has been beat to death but I would like to get an input on my idea. #1 running this generator outside would be a very tough task, so have been crunching ideas to install it in the garage. I have standard 3br house, attached garage with FROG. I have a 8800w generator I planned on running off natural gas. Planned on building a generator box in the corner of the garage, with a large fan installed on the garage side of the box to push the generated heat thru a vent out the side of the house, now for the kicker, the exhaust. Recently I upgraded my gas hot water heater to a gas tankless which has its own exhaust out the side of the house, so that leaves the old hot water heater exhaust out the ceiling to the roof. Whats your input on running the exhaust to that exhaust stack leading to the roof if I installed a inline fan at the bottom of the stack to push the exhaust up the stack? I would of course double wrap the exhaust to the stack with insulation to keep it safe and cool in the garage and install CO detectors in the house and garage. If this sounds acceptable any suggestion for a muffler. I think I have hit all the major safety points and would love the input from others here. Thanks all


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## motormonkey (Jul 10, 2016)

> ... running this generator outside would be a very tough task...



Why?


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## jkingrph (Sep 18, 2017)

If you are going to have an exhaust vent for hot air with a fan, why not put the engine exhaust through the wall there. If you can get an absolute seal on all joints going up through the ceiling, I think you would be ok, and probably no need for a fan to take exhaust outside, just extend the exhaust stack above the roof and cover it with a water heater stack to prevent rain leakage. The engine should have enough power to push the exhaust up and out, just use a larger diameter tubing to lower back pressure, possibly some of the double or triple wall stack like for a woodburning fireplace.


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## speedy2019 (Jan 29, 2019)

I store my generator outside at the side of my house for ease, with a thick water proof cover over it. Not ideal as it gets slightly damp in places, but its ok and it seems to start fine when I need it.


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## tabora (Sep 6, 2018)

firedawgy said:


> ...If this sounds acceptable...


 In no way does this sound acceptable, and is a violation of code most places. Even though a properly tuned engine on propane or natural gas emits much less carbon monoxide than a similar unit running on gasoline, it can still do so at any time and I would be very leery of doing what you propose. Just saying.

Enclosing a portable generator in any structure that is physically attached to a living space is a bad idea. Do something like this: https://www.powerequipmentforum.com/forum/64536-post1.html


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## email4eric (Dec 23, 2018)

I understand that you're doing your best to ameliorate the dangers of using an internal combustion engine inside a house, but...


...it's a really bad idea. Could it be engineered to be safe? Probably but the fact that you're asking about jury rigging a solution using existing exhausting methods tells me you're not probably capable of ensuring absolute safety. Don't get me wrong, I'm sure you're a very bright guy but this is a swell idea until something goes wrong.


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## exmar (Jun 29, 2015)

I know this issue has been beat to death. Yep, think there might be a good reason for that? Why not drag it out in front of the garage when needed-shut the door when running of course.


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## Predator (Sep 19, 2017)

As others have said, the problem is that there is an inherent risk associated with running any fossil fuel engine in an enclosed space attached to living quarters.
It's kinda like the Space Shuttle program. No matter how smart you are, no matter how well you plan......something can always go wrong. And when it does, it's catastrophic.


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## jkingrph (Sep 18, 2017)

Knew a guy who had had a propane service. He had a big portable set up to run on propane, in his garage, with an extended exhaust going through an outside wall. All welded joints on his exhaust system and he never had a problem. 

I do like exmar, and drag mine outside when used, and keep it about 20-25 feet from any door or window.


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## wml52 (Feb 21, 2014)

I have and attached (via enclosed breezeway) garage and have been running my backup generator in my garage for years with no issues. I open the garage door enough to place two large fans on either side of the door, one draws air out, the other pulls air in on the other side to circulate the air. I also have two CO detectors, one mounted on the wall inside the garage and the other inside the entrance to the breezeway neither has never gone off, and yes they have batteries in them...lol.


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## tabora (Sep 6, 2018)

wml52 said:


> I have and attached (via enclosed breezeway) garage and have been running my backup generator in my garage for years with no issues.


It'll work just fine until it doesn't. Kind of like freeway surfing on the roof of a car, bowriding with your legs hanging down in front of a speedboat, wheelying a Ducati at 120MPH, or free climbing a 1000' wall. Good luck...


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## jkingrph (Sep 18, 2017)

I can understand that it would work, and have seen it done. I simply choose not to do so because primarily because of noise. I think a well sealed exhaust system venting outside the building should be adequate. Years ago when I was stationed over in Turkey, our hospital had a whole hospital generator, diesel I think, that was inside a wall common to our lab. When it started up there was no conversation or calls in the lab. I had to inspect a security site up in the mountains that monitered shipping and aircraft activity in the Agean and they had several huge generator sets, all indoors a common building to offices and rec areas.


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