How Dirty is Generator Exhaust

[chefwong]

I guess I'll go with Option C....
The unit has a 12V output as well

I will build a doghouse...
Same concept as above shed but much smaller scale, and put a 120MM fan that is tied into the built in 12V DV output as well.

Same pipe to the exterior - venturi exhaust stack

 

[Bullet]

Build a cage and cover outside

 

[eljefino]

That fan's not going to like the DC, it's pulsed per engine rev and intended for charging batteries.

Can you rig a door hasp lock so it's locked open four inches?

 

[wag123]

All you need to do is run a metal pipe outside from the exhaust outlet and make sure that the pipe is not touching (or close to) anything combustible. If you want to mitigate some of the exhaust noise, dig a hole in the ground outside where the exhaust pipe exits and put a 90 degree in the pipe and an extension so that it shoots the exhaust down into the hole.

 

[volk06]

Originally Posted By: djb
I think people are being a little too paranoid here.

He is planning to vent the exhaust outside.

Most engines product little CO when operating normally. The output is primarily CO2, water vapor and perhaps unburnt hydrocarbons.

The issue is what happens when you operate an engine with no closed-loop control when some of their exhaust fed back into the intake, as happens in an enclosed space. The intake now has much less oxygen and significant CO2. Without free oxygen around, the CO2 is "burnt" to produce CO.

Note that CO generation doesn't always happen with smoke. People over-react to nasty smoke clouds that smell of unburnt fuel and complain they are dying of CO poisoning. In reality there is probably very little CO and minimal danger. Typical CO poisoning situations happen with heaters or charcoal fires, where there is very little noticeable smoke or odor.



This is false.

CO is a product of all fossil fuels burning. CO is created in high enough concentrations to cause problems. I deal with CO monitoring on a daily basis with confined spaces. In small areas with small engines CO IS a major concern. If you don't believe go get an actual air monitor with a CO sensor like an industrial scientific MX6 and stand around a small engine in a small area.

 

[RiceCake]

You guys worry too much. Just ventilate the building somehow will be fine enough. Use a galvanized pipe with an HVAC booster fan in it or something to suck out exhaust. Mod the generator if you want to to just dump exhaust outside.

If you wander into the shed, unless the shed is huge and perfectly isolated from any breeze, just opening the door will make the CO spill out in a minute or two. Gonna be a disaster zone of smog though so I wouldn't make a habit of wandering quickly in there and taking a deep drag.

 

[JimPghPA]

And if you recirculate the hot air leaving the generator after it cools it, so that a decent portion of it is allowed to go back into the cooling air intake, that generator will over heat, and it my even be damaged.

I think you want an elevated cement pad with a level surface and a very big chain anchored into the cement and ground. An electric ground, and a wide enough roof to keep snow and rain off. But open all sides.

 

[bvance554]

Other than air quality, what about cooling? How big is the shed? Seems like it would get really hot in there if you ran it any time other than winter.

 

[01rangerxl]

As long as the exhaust is vented directly outside, I think you will be fine. Many I/C engines are run inside of buildings everyday. Look at any engine shop with a dyno room. Granted, some of those are some pretty serious ventalation systems, but as long as you're getting the exhaust outside of the structure you should be fine.

 

[meep]

OPE engines will vent exh gases via blowby through the vents, it still needs good ventilation. The eu2000i models also move a LOT of cooling air.... very powerful fan section in that thing.

1- pipe the exh to the outdoors. Fabricating that could be a challenge, the nipple on the muffler output doesn't give you much to work with. May have to pull that and go back to the cylinder head if you want a solid connection.

2. make sure the pipe pass-through keeps it at a distance from flammable surfaces.

3. I would monitor summer temps during loaded tests in the summer to make sure the intake air stays cool. If you fan force, you will want the volumes and certain pressures that come from centrifugal fans---- a window fan isn't going to cut it. A gable fan would work.

4. the 12v output is rectified but not regulated. it will drive a small-medium DC fan ok. IIRC it is also not rectified full wave. an electronics fan would be useless both in terms of flow and compatibility with the dirty DC power. A radiator fan will pull waaaay too much current. A cabin A/C fan would probably be ok. you'd want to check it with an ammeter to make sure you don't kill the windings on the gennie. The 12V output WILL increase/decrease with engine speed. It will be lower than 12V in eco mode until it revs up. cheaper to use a 120v fan.

IMO a fenced square with a roof for protection from the rain would be a much easier solution. OR -- a protected "shelf" external to the building itself. You could shield it from rain, and either chain it (case is plastic... ) or drill a security bracket thru the bottom, or even install a removable cover for the shelf. BUT--- I might worry about gas-fed OPE sitting so close to a wooden structure. make sure nearby wood is shielded from potential flame-outs from the muffler, fuel spills, etc..

nice generator btw. very good machine. consider an external run tank for longer runs, it handles them well.

 

[volk06]

Originally Posted By: RiceCake
You guys worry too much. Just ventilate the building somehow will be fine enough. Use a galvanized pipe with an HVAC booster fan in it or something to suck out exhaust. Mod the generator if you want to to just dump exhaust outside.

If you wander into the shed, unless the shed is huge and perfectly isolated from any breeze, just opening the door will make the CO spill out in a minute or two. Gonna be a disaster zone of smog though so I wouldn't make a habit of wandering quickly in there and taking a deep drag.


In an enclosed area with no ventilation this is not worrying too much. Ventilating it to the outside is a different scenario and the best option. FYI the CO won't spill out in a minute or two without any air movement, unless its a tiny area and not very tall. CO is lighter than air.

 

[lars11]

well, i actually killed a genset when young. Placed it i a rellay large plank box, with large holes and openings on several sides, just to suppress sound a bit as we were powering a large stereo.
It ran for like 5 hrs, then died from overheating. Oil splattered out the exhaust etc.
The inside of the box was *not* fresh...
It will use lots of air and start circulating air and hot exhaust.
A 200cc engine at 3000 rpm will cycle like 500liters of air per minute. Your shed will not ventilate this completely so dirt and heat will build up. and then...
Won't work, I kind of tried it.

 

[lars11]

Originally Posted By: volk06

...CO is lighter than air.

No, CO is heavier than air and will drop to the ground and collect in lower areas. It will stay in boat hulls etc.

 

[JTK]

Originally Posted By: lars11

No, CO is heavier than air and will drop to the ground and collect in lower areas. It will stay in boat hulls etc.


Correct. It's funky stuff. My employer has plants that make (cryogenic) 100% liquid CO. There's actually some companies that need it for their processes. Anyway... everyone even remotely close to the process or storage tanks wear continuous atmospheric monitoring. One breath of it and you're gone. I believe they also have to go thru regular blood testing because of CO's cumulative build-up effects.

Also, CO in it's pure form is flammable. It gives off a green flame IIRC.

Joel

 

[JHZR2]

I've seen folks run fairly size able diesel gens mounted in their garages. But, the exhaust is plumbed via growing diameter iron pipe out to the weather. If you could do this, and then have a fan and enough airflow to support the combustion and cooling (simple calculation) you should be OK. I'd be careful with the exhaust runs through the walls.

 

[volk06]

Originally Posted By: JTK
Originally Posted By: lars11

No, CO is heavier than air and will drop to the ground and collect in lower areas. It will stay in boat hulls etc.


Correct. It's funky stuff. My employer has plants that make (cryogenic) 100% liquid CO. There's actually some companies that need it for their processes. Anyway... everyone even remotely close to the process or storage tanks wear continuous atmospheric monitoring. One breath of it and you're gone. I believe they also have to go thru regular blood testing because of CO's cumulative build-up effects.

Also, CO in it's pure form is flammable. It gives off a green flame IIRC.

Joel


Sorry but you guys are wrong. The vapor density of CO is 0.97 which is LESS than the vapor density of air which is 1.0. Since the VD is lighter for CO, it will float on top of regular air. Can't defy the physics.

 

[lars11]

Originally Posted By: volk06
Originally Posted By: JTK
Originally Posted By: lars11

No, CO is heavier than air and will drop to the ground and collect in lower areas. It will stay in boat hulls etc.


Correct. It's funky stuff. My employer has plants that make (cryogenic) 100% liquid CO. There's actually some companies that need it for their processes. Anyway... everyone even remotely close to the process or storage tanks wear continuous atmospheric monitoring. One breath of it and you're gone. I believe they also have to go thru regular blood testing because of CO's cumulative build-up effects.

Also, CO in it's pure form is flammable. It gives off a green flame IIRC.

Joel


Sorry but you guys are wrong. The vapor density of CO is 0.97 which is LESS than the vapor density of air which is 1.0. Since the VD is lighter for CO, it will float on top of regular air. Can't defy the physics.


Ok they are close, but depending on temperatures in the room, it may collect at floor level or in between too. Don't do the mistake and think CO will ventilate by itself. It is a very dangerous gas, be careful.

 

[JimPghPA]

Originally Posted By: JHZR2
I've seen folks run fairly size able diesel gens mounted in their garages. But, the exhaust is plumbed via growing diameter iron pipe out to the weather. If you could do this, and then have a fan and enough airflow to support the combustion and cooling (simple calculation) you should be OK. I'd be careful with the exhaust runs through the walls.


The exhaust of most of these engines has a female pipe thread. You can connect black threaded pipe to them, but it is very important that you put a flexible pipe near the engine connection. The vibration of the engine will cause any ridged pipe only set-up to fail, and possibly also damage the engine.

McMaster-Carr sells a flexible pipe with a stainless steel wire mesh outer covering and pipe fittings on both ends.

 

[morris]

dont worry it does meet government specs. LOL

 

[JimPghPA]

It would be a very good idea to get a CO alarm if you are running an engine indoor and do not have one. If it is a AC powered one be sure that the circuit is kept hot when the gen-set is running. A battery powered one would probably be a better idea since it is for use during a power outage.