[NA] - exhaust hose

TMetzinger

TMetzinger

Final Approach
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Tim
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My mom got a generator installed in her garage. It's on wheels so fairly easy to move outside to operate safely, that's their default plan.

But I remember seeing the tailpipe hoses at garages that would allow her to NOT wheel her generator out in the bad weather (which is probably why she needs it in the first place) but instead do just open the garage door a bit and unroll the hose to lead outside.

Anybody have a source/description for this stuff? I'd be looking to buy 20' of hose and the necessary hardware to adapt it to the generator exhaust.

Will have to look at the generator to be sure there is enough of a exhaust lip to work with.
 
be sure to buy a CO detector.
Are there living quarters attached, or upstairs?
 
The hose is probably okay but only if your garage has one or two windows that you can open as well. Otherwise I would not trust it. CO is sneaky
 
Tim,

The problem you're gonna have is fitting a pipe/hose/whatever to the exhaust of the generator. My gen set (and most I know) have a pretty odd shape to the muffler. Much better if the unit can be wheeled outside. It'll also help big-time from a noise standpoint.

I think you'd be a lot better off building a little outdoor shelter for the unit.

Bill
 
Thanks.

I'm gonna see if the manufacturer offers anything. My grandfather had one and it had plumbing to the outside through a hole in the wall.
 
I assume you don't have any building codes that you'd have to deal with...

One item you might consider is an inline exhaust fan such as used for dryer vents. I have a gas dryer with exhaust ducting running through the garage and then outside. There is an inline fan that is turned on by a pressure switch sensing the "push" of air from the dryer. This item, or something similar, might be useful to reduce the risk of CO penetration and buildup in your living area.
 
TMetzinger said:
My mom got a generator installed in her garage. It's on wheels so fairly easy to move outside to operate safely, that's their default plan.
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Tailpipe hose is pretty leaky. Not something I'd want to use to route exhaust out of an enclosed area.

I've found it in local auto part stores. But only in short lenghts.
 
You could get someone to weld it on. If they take the stock muffler off and do it on a bench, it could be made airtight.

I've field welded (with a crappy 110v flux-core) a junkyard muffler to a loud generator before. Worked great but would never trust it in the garage unless I could have done it on a bench.

Also if your garage has windows that open, you can buy a window fan that fits like a window A/C unit into your garage window. They can be made to pull quite a bit of air out of a room, creating a weak negative pressure in your garage.

Good welded connection + window fan + several CO detectors and I think you're good to go.

Fire is of course a concern too, so your generator placement, exhaust routing is critical.

Honestly I'd go for the outside shelter idea. Too many issues putting it in the garage and you also must consider legal things like building codes and insurance.. if the house burns down because of the generator, will your policy cover? etc...
 
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kyleb said:
Tailpipe hose is pretty leaky. Not something I'd want to use to route exhaust out of an enclosed area.

I've found it in local auto part stores. But only in short lenghts.
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Then how do all these repair places get away with it?
 
TMetzinger said:
Then how do all these repair places get away with it?
Click to expand...

Tradition.

Back in the good old days, we didn't worry about sissy stuff like carbon monoxide. (How do we know that it actually exists? Has anyone actually seen any?)

One thing to consider, your typical modern, computer controlled, catalyst equipped automobile doesn't put out hardly no CO at all. Plus, running in a garage, it is just idling. (Inside a closed up semi trailer it takes an hour or two of idling to get CO up to really bad levels). Your generator, on the other hand, is not going do have such a squeaky clean tailpipe. It might even be running rich of peak - CO city. Plus at high loads, it will use up O2 a lot faster than an idling car (as O2 goes down, CO goes up).
 
One caution, if you weld a transition pipe on to the exhaust of a small portable genset, weld on a very wide expansion fitting. Most modern portable gensets have tuned exhausts which will be affected and you may lose power if you extend the exhaust pipe out at the same diameter. I would weld on a very short extension pipe and use a high temperature (exhaust) flex coupling to an expansion fitting and larger pipe. I would personally use welded schedule 10 black steel pipe (4" should be plenty for anything under 1KW) vented out the side wall through a 8" or larger diameter hole out the sidewall and a large metal flashing. Put a downturn in the pipe so rain doesn't collect in it. Probably overkill for a residential installation but it's similar to what we would do for large interior engine driven gensets.
 
TMetzinger said:
Then how do all these repair places get away with it?
Click to expand...
Most are in buildings much larger than Mom's garage, and have lots of ventilation -- if only from having the big roll-up doors opened and closed regularly as cars are moved in and out.

I've looked at the same issue when considering adding a small (4-5 KW) generator to our list of crap to spend money maintaining. So far it looks like either wheel it outside before starting, or build s small shelter outside and run the wiring thru the wall. Neither option is all that appealing, given our history of maybe 4-8 hours of total power outage per year.
 
a lot of RVers (wheeled campers, not winged fun) use a venuri pipe to route generator exhaust up and away from the coach - google genturi - maybe some workable ideas there? I find it easier to put the genny outside and snake the cord under the door than I think it would be to route an exhaust hose under the garage door.

Way, way back when - I worked in an auto shop in high school. They did have exhaust pipe hoses and round ports in the rollup doors - a short run, a big shop and lots of ventilation, I suppose, kept us alive back before we knew better.
 
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gkainz said:
Way, way back when - I worked in an auto shop in high school. They did have exhaust pipe hoses and round ports in the rollup doors - a short run, a big shop and lots of ventilation, I suppose, kept us alive back before we knew better.
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We knew better back then, too... carbon monoxide poisoning was well known and well understood. There never has been any mystery about it. Like you said, short runs, good ventilation and a large space keeps it workable even now. I don't think I have ever seen an auto repair shop without exhaust hoses/vents. It's just not such a great idea in a small garage with no ventilation to speak of, like at home.
 
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