Mep-003a air flow ouestion

[spaceman]

Hi all,
i have a mep-003a genset that i would like to enclose in a building to reduce the noise level.
the question i have is i intend to place set on a stand about 2 feet off the ground and enclose all the way around the unit with the exception of front shroud and the underside .
the sides will have about one foot on each side for ventalation.
exhaust will be routed out the roof.
the bottom will be open.

will the genset have enough air flow to allow proper cooling?
thanks for any thoughts

 

[Speddmon]

Just my but I think it should be fine. Sounds like you're leaving way more air space that the ASK's leave. I would just make sure you're not recycling the warm air inside your enclosure, shed or whatever. It's going to get warm inside the building with the set running so I'd make a provision for fresh air.

 

[LanceRobson]

Enclosed on the sides and open on the ends would be better.

With three sides closed you might get a lot of heat build up due to swirling air. Maybe wide doors that can be open when running? They could be incorporated into the plan by using them to further channel the noise away from the area you want quiet.

Another option would be to duct air through the wall and directly to the fan intake.

The walls being only a foot away might block airflow. Note that when a generator is trailer mounted the canvas ends (sides if cross mounted) are rolled up so the set is essentially in an open shed.

What your worrying about is getting a lot of cool air with no restriction to the intake. A wall a foot away at the intake end will reduce the airflow. Any restrictions to hot air exhaust will cause it to swirl around the unit and heat things more than needed.

Consider using flex exhaust hose to a pair of low restriction straight through tractor style mufflers with flappers. They could be mounted horizontally to reduce the visible signature. If horizontal, drill a few weep holes in the bottom side of the mufflers to allow condensate to drain. If verticle, put the weep holes at the lowest point of the exhaust system. The flex hose transmits less vibration (the cause of all the noise) to the outside of the shed than pipe does.

Noise attenuation is all about de-coupling surfaces and making the noise pass through materials of varying densities. Different wave-lengths of sound are reduced in intensity by different densities of material. Avoid a hard interior surface. Consider a layer of faom board or even encapsulated fiberglass insulation bats.

If using conventional framing, use a 2x6 sill and plate with 2x4 studs at 24" centers. Stagger every other stud on the opposite long edge of the plate and weave the insulation around the studs horizontally. This keeps vibration from the inner wall from vibrating the outer wall and will cut down the drumming effect of a normal wall.

At the extreme end, a flat roof or ceiling can be de-coupled by using staggered joists (rafters) and putting a one inch layer of sand over the inner ceiling before installing loose insulation and the upper sheating. All the energy expended in vibrating the sand would have come out as noise. It really knocks back noise coming through a ceiling (roof).

If you need some simple drawings, shoot me a PM. One of my construction standards book has a chapter devoted to noise attenuation. I'll mail or FAX you some drawings.

Place the open ends of the shed facing away from the area you want kept quiet.

Lance

 

[Bill W]

As you can see in pic,the a.s.k. puts alot of restriction on the exhaust/cooling airflow( obviously to no ill affect), so as mentioned a good unrestricted/ducted intake (cool air) along with a good exhaust escape and you should be covered

 

[atankersdad]

Great post Lance, and well thought out. I will be building a shelter to house my Gen unit and think you have covered most if not all issues. I would like the building small enough that it does stand out, but large enough to allow access to all sides of the unit for pm/service and a way to extract and replace if needed.

 

[spaceman]

Thanks to all for your thoughts and advice.
this is a great site for a newbie like myself
i just got this genset and looks like i got a deal for the hours on it and the price i paid 305 hrs.......$ 325.00.......
thaks again

 

[Speddmon]

If it runs and makes power you get a GREAT deal