Indoors engine/outdoors exhaust?

[Seldom Seen Slim]

I'm installing our 6kw generator in a permanent location in the garage - and haven't got to getting the exhaust safely outdoors.  Anybody got some ideas?

Regular 16"O.C. studs w/cedar siding and 6" fiberglass ins.  The garage is heated - so I've gotta come up with something to let the bad stuff out -- and keep the cold out there, too.

It's kinda difficult to find 1" flex tubing - which'll have to have the 1" or so exh. pipe from the B&S affixed by good chewing gum or something.  Once outdoors I'm going to muffle the noise - so might as well use hard pipe (instead of flex - avoid rapid deterioration in the weather?) leading to a muffler, hard mounted on the (outdoor) wall of the garage.

Okey-dokey.  There's my query for the day.  Anybody have some good suggestions?

PS  Yes, we do have power outages out here in the woods.  They're not frequent - seldom even a flicker - but when the power goes out it stays out for 12 hours instead of a few minutes here and there.  Having lights, heat, and water 9 a big generator, that is - is dandy when the neighbors don't.

[Milwaukee Midget]

Most of the backup generators I've seen set up on a slab outdoors.

Is this an actual home unit, or are you going 100% hillbilly on us?

The reason I ask is that I've done the AV work for Generac for their annual employee meetings for 4 years in a row.  I've visited all of the factories in Wisconsin, and they really don't have a lot of pieces in their "Warranty Returns" department.  They're pretty darned impressive.

You can pick up a 7K unit for less than 2K, and I expect you're quick enough to wire it into the house yourself.

I doubt you'd need to pull a permit in the UP - as long as you kept quiet about your intentions.

I expect Nancy would be able to get one at a discount at the big box.  Hook it up to the LP, and you're good to go.

[Buickguy3]

   If you're going the Hillbilly way, do yourself and us a favor and get some sort of CO auto shutdown switch. We wouldn't want them to find the two of you in the morning cold with green boogers.
      Doug 

[jauguston]

Build a box to keep it out of the weather and put it outside. That is the SAFE way.

Jim

[Ken Yooper]

Jon- - Keep it out of the house and your garage too if it is attached to your home because you never know if or when a crack might develop in the exhaust structure. Even a leaking head gasket will cause trouble, not to mention a fuel leak.  Like others have said, build a hut for it and if it were me, I'd locate the hut some distance from your living quarters too.  

About the exhaust routing through a wall of your hut - you might be able to install a common braided stainless flex joint from an automobile.  Even the muffler shops down here have them in various diameters and lengths.   Although not completely flexible, at least they will provide a little "wiggle room."   Also might want to seek the opinion of some one at your local fireplace store – they will have everything you need for safely routing an exhaust through a wall.  They will know the minimum clearances to combustibles too.   Their stuff survives chimney fires so it should be OK for a gen-set exhaust.

Just my thoughts -

KB

[Seldom Seen Slim]

We already have the generator.  6000 watt 120/240 gasoline powered.  It works fine - but I'd like a more permanent mounting location.  Outdoors isn't a starter.  If the power goes out I don't want to have to shovel through 2-5 feet of snow to get to it, and the layout of our yard/sidewalk doesn't lend itself to the outdoor task, either.  The garage is wired for 240 VAC in both directions.  The generator system works well enough, but the amount of snow that falls where it would sit makes the idea a non-starter.   So it'll be inside with exhaust going out.

Thanks so far.  Oh, yeah -- the garage is completely disconnected from the house -- by about 30 feet or so of sidewalk.

[Ken Yooper]

Detached, thirty feet way?   Your garage sounds like a pretty good "hut".

[Stainless1]

Jon, use a flex hose like this
http://processhose.com/1-in-t316-ss-annular-corrugated-metal-hose-assembly-with-t304-ss-single-braid-af5550.html?gclid=CjwKEAjw8NaxBRDhiafR-uvkpywSJAAxcl6fchySq4Zm4AHqXdilxlZJPaDlZy2ZoQ2nUR-fs5XTKBoCqSXw_wcB
pass it through the wall in another pipe, wrap it with exhaust wrap thick enough to fill the outer pipe.  If it leaks too much air for you, use hi-temp RTV like the stuff that you seal an air tight stove with to fill the gaps.

Thats how us other Hillbillys would do it.  

[sockjohn]

Sounds like the garage is pretty well sealed up.

Will there be enough fresh air coming in for the generator?

I assume air cooled generator, so will it overheat the space if running for extended time periods?  I would assume in winter it wouldn't get hot enough to matter, but who knows.

[sofadriver]

The forced air propane furnaces on my boat have pipe within a pipe chimneys. The exhaust goes out the inner pipe while the furnace drafts thru the outer pipe.  That way no warmed air from the room gets exhausted.

https://www.fisheriessupply.com/dickinson-marine-newport-propane-heater-pipe-extension

[bbarn]

I did a 3cyl 25kva diesel right out the side wall of my warehouse once. Just plumbed it with regular exhaust pipe off the shelf. Put an elbow on it when it exited the wall and ran it up with an old fashioned tip-up flapper on top to keep the rain and birds out.

Since it was an emergency use only deal it didn't run but the 5 minutes a month to test the battery and circulate the oil. The exhaust hardly got any wear on it so it rusted less than any I have ever had on my cars. You also have the advantage of putting a regular muffler on it to help quiet it down when running.

I got fancy with mine and installed an automatic line transfer switch and hooked my entire two floor office including air conditioning to the darn thing. Once I did that, we never lost power again!!!

Depending on how far the run is you may not need to deal with heat at the exit wound you make in the wall. Mine was about a thirty foot run. The pipe wasn't insulated so by the time it got to the wall it was mostly room temperature. If I had to run it through a wall and worried about heat I would just go with a 4" double or triple wall pipe and feed my exhaust tube down the middle. Make a sheet metal cover to keep the 2nd and 3rd walls from allowing the weather on the outside to mix with the weather on the inside.

[JimL]

You should compartment the generator with an automatic ventilation system that runs a vane switch.  If the compartment isnt making airflow, the genset stops.  I have done this using a 12v cooling fan run off of the generators 12v.  You must manually hold the vane open to start the generator....you get the fan running to keep the vane switch open which holds the switch relay on.  Anything goes wrong, the genset shuts down.

You get the switches from heating/AC suppliers.  The fan must be a draw system, not pressure in.

The blowby from the generator crankcase can kill you as dead as the exhaust.  It takes a little longer, but it gets worse on engines that are run infrequently.

Blowby deaths are weird, because they act like some kind of flu bug for a few days until you tip over in your sleep.  I had a good friend was the sole survivor of three men in an "outside exhaust system" structure.  All they ever noticed for a problem was hot oil smell.  They were all sick until he was the only one woke up.  He never got his health all the way back, even though they put him in a hyperbaric oxygen chamber...probably spelled that wrong.

This is a little scary.

[fordboy628]

You should compartment the generator with an automatic ventilation system that runs a vane switch.  If the compartment isnt making airflow, the genset stops.  I have done this using a 12v cooling fan run off of the generators 12v.  You must manually hold the vane open to start the generator....you get the fan running to keep the vane switch open which holds the switch relay on.  Anything goes wrong, the genset shuts down.

You get the switches from heating/AC suppliers.  The fan must be a draw system, not pressure in.

The blowby from the generator crankcase can kill you as dead as the exhaust.  It takes a little longer, but it gets worse on engines that are run infrequently.

Blowby deaths are weird, because they act like some kind of flu bug for a few days until you tip over in your sleep.  I had a good friend was the sole survivor of three men in an "outside exhaust system" structure.  All they ever noticed for a problem was hot oil smell.  They were all sick until he was the only one woke up.  He never got his health all the way back, even though they put him in a hyperbaric oxygen chamber...probably spelled that wrong.

This is a little scary.

Slim,

Inhaling ANY hydrocarbons, either burned or unburned, is bad news for your health.    Even very low concentrations, over a long period, can accumulate in the body, and as a result, affect your liver and kidneys.    Trust me on this, I had it happen to me, and it has taken me years to recover.

Use the sealed compartment method combined with outside ventilation of the compartment and an external exhaust.    You can't be too careful on this.

 
Fordboy

[Finallygotit]

Use the sealed compartment method combined with outside ventilation of the compartment and an external exhaust.    You can't be too careful on this.

 
Fordboy

This!! ^^^^^^^^^^^  Please!

 

[JimL]

I worked a job in the Rockies where we needed the generator outside in the cold.  We had to run Homelites because the 4-strokes wouldnt start at twenty below zero (which was our daily high temps at that altitude). Is there any way you could build your enclosure outside with enough heat to let it start?  A couple light bulbs in an insulated box would do it.

Have a little two-stroke generator with the "canned gas" on hand.  Those canned gas products are good for years of storage.  Dont store fuel in that one and add more oil after you open the pre-mix can.  That two stroke will start to give you a way to put more heat into your big one. 

You still have to go outside because the main generator has to be checked before you fire up and you must uncap the exhaust and open vents.  The critters will build nests in the engine, coming in through the exhaust.  A friend of mine broke the block on an inline six when the piston (in the cylinder that shut down with exhaust valve open) crushed the nest and babies at TDC on a spring startup attempt.