Exhaust piping the mep-003a

[ctfjr]

I have placed my genset inside my garage between two garage doors. The generator is set back a bit so the exhaust pipes are about 30 inches from the door.

My plan is to pipe them both up about 42 inches then run horizontally the 30 inches so they are just inside the door when its down. When I want to run the unit the door of course will be open and I am thinking of slipping some 'extension' piece over the 1-1/4 pipes to get it 12 inches or so beyond the outside wall.

This plan will require 2 90 degree elbows for both units and a couple of 45 degree elbows in addition for one of them to make an offset. So. . . I have 2 questions about this - first, is there an exhaust restriction with these fittings that I should be concerned about? second, should I leave provision for a drip leg at the low point?

Is there anything I am missing here?

 

[skidunits4you]

There is always some restriction with elbows but no big deal here. I would want the outlet more than a foot outside door so gases stay outside. The bigger problem will be that you should use flex pipe to stop vibration and it would need to be supported. you can pipe the 2 outlets together and run one pipe outside. I would elbow up run to flex pieces about a foot and wye them together and run one 1 1/2" pipe outside. On my units once outside I run them up to the roof line and put an exhaust flapper on them to keep water out. now only need to open doors a small amount to let air in and exhaust is well away for safety.

 

[ctfjr]

There is always some restriction with elbows but no big deal here. I would want the outlet more than a foot outside door so gases stay outside. The bigger problem will be that you should use flex pipe to stop vibration and it would need to be supported. you can pipe the 2 outlets together and run one pipe outside. I would elbow up run to flex pieces about a foot and wye them together and run one 1 1/2" pipe outside. On my units once outside I run them up to the roof line and put an exhaust flapper on them to keep water out. now only need to open doors a small amount to let air in and exhaust is well away for safety.

Good point skidunits4you! I had thought about a flex line going a few feet from the power distribution box to ridgid plastic conduit (going to punch a 1-1/2" hole on the top for bringing in the electrical connections). Even more important for the exhaust side! Thanks

 

[Nonotagain]

The MEP-003A generators used on the laundry units were issued with two stainless steel flexible pipes approximately 10 feet long. These just screw onto the pipe fitting at the muffler.

I have a spare set that I've thought of selling

PM if interested.

 

[PeterD]

If you do this, please have a good friend or relative, who is not living with you, post the outcome. Running such a generator in the garage with that type of exhaust system strikes me as utterly foolish.

The only acceptable (and marginally, at that) would be one that meets code, so would have to stick up well above the roof line. Look at the codes for venting gas appliances (water heaters, space heaters, etc.) and you'll have an idea. If you do not get above the roof line, you will get CO into the building, doors open, closed, or whatever way you want. Just venting below the roof line leads to the problem that whenever the wind blows wrong, (and it will) the exhaust will blow into the building.

 

[Keith_J]

Diesels operate with far excess air over most ranges of operation. Diesels are far cleaner in CO than gasoline engines. If you really wanted to make it safer, duct the cooling air out with the exhaust out of the building. This will also reduce noise.

 

[PeterD]

Keith, you are 100% correct. My brain was set on gas engines when I made that post! (OK, I'm an idiot in this thread!) The only time a diesel engine develops CO is when it is heavily loaded...

I'd still plumb it above the roof myself anyway, for the other reason: smell! My MEP-004A has the ASK which plumbs the exhaust straight up (instead of out the back) and that makes a big difference. I can not normally smell it in the house (but I can't say whether my neighbors smell it however!)