Exhaust for whole house genset

[corn18]

I just got my whole house backup genset in place and have it running its 5 hour break in on natural gas hooked directly from the house. I would like to run the exhaust up the side of my brick house a short way. I already attacked a flexible extension. The end of the extension is very hot. Can I just get some 1 1/2" black pipe and run that up about 8 ft and just insert the extension into that? The space around the end of the extension will act as a venturi sucking ambient air up the chimney with the exhaust air. Appreciate any thoughts and advice.

 

[plympton]

I'm pretty sure the exhaust gasses are heavier than air, so they'd sink. If you run them up - I'm not really sure what will happen. Will they act as a compressible fluid and just get pumped up the stack and then drop back down / get caught in the wind?
Likely the extra back pressure won't be a big deal, but it's a possibility. The moisture and condensation very likely could cause issues, though.

 

[corn18]

From the RV folks, they do this all the time with their onboard generators. This is something I found: "CO is slightly lighter than air at NTP. The mixture of CO, CO2 and H2O vapor is carried upward by thermal convection (chimney draw). "
All of this is under an eve that is 20 ft up so the vertical pipe should stay dry.

 

[corn18]

Installed the vertical black pipe. Works a treat. I thought the black pipe would stay cooler but it gets hot as hades.

 

[plympton]

How does the pipe affect the quality of the sound? How did you affix the bent (copper?) to the black (steel?)?

 

[corn18]

How does the pipe affect the quality of the sound? How did you affix the bent (copper?) to the black (steel?)?

No effect on sound. The exhaust is the quietest thing on this beast. I would much rather stand on the end where the exhaust comes out than the other end. So much mechanical noise, it hurts.

The small bendy pipe that is attached to the exhaust output is stainless steel. I just shoved it up into the black vertical pipe about eight inches. No attachment required.

I am going to wrap all the pipes in heat wrap that they use on headers and exhausts. If my dogs or anyone touches those, they will get burned.

 

[Bluedog225]

Why are you going this? I see no real benefit and wouldn’t mess with the factor exhaust design.

 

[Browse]

I don't see any benefit but I'm no expert. Exhaust from a generator is much less than an idling car, especially running on natural gas. Outdoors, it will simply blend with the air and dissipate. I've seen enclosures for keeping the sound down and most of those have exhaust fans to keep the generator cool and the gasses out of the enclosed space. I'd be concerned about backpressure on the engine from the restricted exhaust. It could all also be fine. Dunno.

 

[Q-Dog]

You should be trying to get the exhaust and heat AWAY from the house. NOT right next to the house. Your exhaust pipe needs to at least extend above the roof.

Do you have any windows on that wall? Is there a soffit or roof overhang above that pipe?

 

[corn18]

The reason I am doing it is because the stock exhaust blows right on the gas meter. It's 8 ft away but it was still warm and I did not like that.

The black pipe is on a 6" standoff. And the roof is another 16 ft up.

 

[Bluedog225]

Turn the genny. Or put up a heat shield.

It’s a backup genny, right? I’d keep it in the shed or garage till needed. And point the exhaust wherever when needed.

I’d ditch the mods.

 

[corn18]

Turn the genny. Or put up a heat shield.

It’s a backup genny, right? I’d keep it in the shed or garage till needed. And point the exhaust wherever when needed.

I’d ditch the mods.

It weighs 230 lbs and has to be hauled up a hill in the rain/snow. Not gonna happen. Pissed me off every time I had to use it. So I started putting it right outside the garage and ran a 75' 50A RV extension to it. Equally irritating. It's under an eve with a cover on it. It has rained hard since I put it out there and it stays dry.

I may just move it to the left 5 ft and remove the mods.

 

[seneysolar]

You can just run it right into the ground, dirt makes a good muffler.

Also a barrel of water works good.

 

[corn18]

I just moved it 5 ft left. All good now. Thanks for convincing me this was a bad idea. I agree. My gut told me it was dangerous and stupid.

 

[WindWizard]

I ran my exhaust on my generator through my garage wall so that I did not need to keep moving it outside. I needed to wrap the pipe to keep the outside of the pipe cooler. I would suggest wrapping yours as well. It keeps the temperatures manageable.

https://www.amazon.com/gp/product/B011B99B0I/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[42OhmsPA]

I just moved it 5 ft left. All good now. Thanks for convincing me this was a bad idea. I agree. My gut told me it was dangerous and stupid.

Wouldn't that put it right next to the meter box and dryer vent?
If the muffler extension falls out of the black pipe could exhaust gas be pushed back through the vent?

 

[JRH]

From the RV folks, they do this all the time with their onboard generators. This is something I found: "CO is slightly lighter than air at NTP. The mixture of CO, CO2 and H2O vapor is carried upward by thermal convection (chimney draw). "
All of this is under an eve that is 20 ft up so the vertical pipe should stay dry.

CO is somewhat Neutral and will waft around here and there…that’s why they generally don’t recommend putting a detector at the floor like propane or at the ceiling like smoke or heat detectors.

 

[corn18]

Wouldn't that put it right next to the meter box and dryer vent?
If the muffler extension falls out of the black pipe could exhaust gas be pushed back through the vent?

I moved it left farther from everything. It isn't like it was melting anything where it was. I could hold my hand in front of the gas meter and it wasn't hot. Just warm. Made me nervous.

Still need to level it all out and secure it with rebar stakes. Will move that hose further left as well. We never use that hose.

You like my log chain? All that will do is keep honest folks honest. I can cut through that in 10 seconds and it's grade 70 chain.

 

[42OhmsPA]

I moved it left farther from everything. It isn't like it was melting anything where it was. I could hold my hand in front of the gas meter and it wasn't hot. Just warm. Made me nervous.

Still need to level it all out and secure it with rebar stakes. Will move that hose further left as well. We never use that hose.

You like my log chain? All that will do is keep honest folks honest. I can cut through that in 10 seconds and it's grade 70 chain.

I did get a chuckle out of the chain around the gas line below the meter. Hopefully it makes someone dumb think twice.
It would probably be easier to cut the gen frame than the chain.

 

[corn18]

I did get a chuckle out of the chain around the gas line below the meter. Hopefully it makes someone dumb think twice.
It would probably be easier to cut the gen frame than the chain.

I'm counting on the 230 lbs and a big hill to keep folks away.