mep-003a running temp in a closed environment

[robkiller]

Is or has anyone ran an mep003a or 2a in an enclosed environment with the exhaust having a way out of the enclosure and no other air exchange assistance? Does heat become a huge problem?

I am asking since I have an enclosure that I placed an mep3a in. I have ported the air brought into the generator out of the small structure(exhaust). I have a small 4" vent for any exstra air to leave the structure. I am wondering if I am going to need to move more of the air in the building than what will be moves with this setup.

Anyone with experience in this area have some advise?

 

[dependable]

It is an air cooled motor, and will need some venting in addition to combustion air supply and exhaust. If you can look at one with an ASK, that might give you some idea.

 

[PeterD]

The size (CU FT) of the enclosure is important, as well as insulation. Personally I'd not run any engine in an enclosed space without positive air displacement means sufficient to ensure it doesn't overheat.

 

[Isaac-1]

Your going to need a lot more cooling air flow than that. The spec sheet for the Onan DJC(a civilian generator powered by a close cousin of the same engine) specifies a cooling air volume of 800 CFM (cu ft per minute) air flow (this assumed to be correctly vented across cooling surfaces on the generator and engine, from one end to the other with appropriate flow baffles). In addition to this you would also need to supply air for engine consumption, I don't see a spec fo this, but that is going to be about another 75-100 CFM.

Ike

 

[robkiller]

So I am going to make the change so that the engine fresh air intake (air filter) is getting oitside air. I was able to find that the unit needs 1600 cfm at 2000 rpm which is provided by the intake fanct to cool the unit. This will be fresh air just like the ask provides. I was not able to find any other info for cfm besides that. The ask from what I can tell correct me if I am wrong but only seems to have the one air intake at the fans end and the rest of it is covered entirely with that one opening. But I only have pictures to look at.

So with all this you think I should add another air supply of about 1000 cfm across the generator?

Thanks this is good info!

 

[robkiller]

So I am going to make the change so that the engine fresh air intake (air filter) is getting oitside air. I was able to find that the unit needs 1600 cfm at 2000 rpm which is provided by the intake fanct to cool the unit. This will be fresh air just like the ask provides. I was not able to find any other info for cfm besides that. The ask from what I can tell correct me if I am wrong but only seems to have the one air intake at the fans end and the rest of it is covered entirely with that one opening. But I only have pictures to look at.

So with all this you think I should add another air supply of about 1000 cfm across the generator?

Thanks this is good info!

Just to make sure my post is clear I do have the intake fan just like the ask getting fresh outside air. I have also ported the exhaust and hot air from the cooling exhaust out of the structure just like the ask does.

 

[Munchies]

The TM has specs for minimum distances and volume of enclosed spaces and minimum cooling air capacity

 

[robkiller]

The TM has specs for minimum distances and volume of enclosed spaces and minimum cooling air capacity

What are they or where did you find those?

 

[dependable]

The ask from what I can tell correct me if I am wrong but only seems to have the one air intake at the fans end and the rest of it is covered entirely with that one opening. But I only have pictures to look at.

The ASK is pretty much open at the bottom.

 

[gimpyrobb]

If you have fresh air run to the(combustion) air intake of the motor and to the air intake of the cooling fan, you should be fine. A vent for heat to radiate out of the enclosure would be good too.

 

[robkiller]

If you have fresh air run to the(combustion) air intake of the motor and to the air intake of the cooling fan, you should be fine. A vent for heat to radiate out of the enclosure would be good too.

I will place a vent for radiating heat also. I am going to keep and eye on the ambient temp with in the building. Winter will be fine summer is what I need to watch for.

 

[SteveH]

I will place a vent for radiating heat also. I am going to keep and eye on the ambient temp with in the building. Winter will be fine summer is what I need to watch for.

I'm interested in what you're doing here. I've got my MEP003a on a concrete pad, in an ASK, but really want to have some more protection, mainly to keep rodents out, but also so I can an auxiliary fuel tank in the shed.

I'm considering a 10x10 shed, with the 'inlet' end of the ASK ducted through the wall, and a vertical metal duct coming out of the 'hole' in the top of the ASK, and through the roof to exhaust the hot air. I have a pair of the stainless muffler pipes that I'd use to pipe the exhaust out separately (but up through the center of the duct). I'd probably also add another pair of vents (inlet/outlet) in the shed, though I've noticed that the ASK body doesn't even get warm, so I use most of the heat comes out that hole in the top.

How similar is this to what you're planning? I'm looking for good ideas at the moment, but want to get this done before winter arrives...

-Steve

 

[robkiller]

I'm interested in what you're doing here. I've got my MEP003a on a concrete pad, in an ASK, but really want to have some more protection, mainly to keep rodents out, but also so I can an auxiliary fuel tank in the shed.

I'm considering a 10x10 shed, with the 'inlet' end of the ASK ducted through the wall, and a vertical metal duct coming out of the 'hole' in the top of the ASK, and through the roof to exhaust the hot air. I have a pair of the stainless muffler pipes that I'd use to pipe the exhaust out separately (but up through the center of the duct). I'd probably also add another pair of vents (inlet/outlet) in the shed, though I've noticed that the ASK body doesn't even get warm, so I use most of the heat comes out that hole in the top.

How similar is this to what you're planning? I'm looking for good ideas at the moment, but want to get this done before winter arrives...

-Steve

This is exactly what I am doing take away the ask. As soon as I get the final duct work done I will post pics. Mine is not 10x10 its 80inches by like 40 inches buy 40 inches tall.

 

[SteveH]

This is exactly what I am doing take away the ask. As soon as I get the final duct work done I will post pics. Mine is not 10x10 its 80inches by like 40 inches buy 40 inches tall.

Thanks! Sounds like you're really building something that is an alternative to the ASK. That had been my original plan until I lucked into a NOS one. Definitely interested in seeing how you do it!

 

[ETN550]

As a general rule 1/3 of the fuel burned goes to power, 1/3 goes out the exhaust and 1/3 goes out with the cooling system. Then there is some radiated by the block, etc. Now the 1/3 that is power goes to the gen and the gen also rejects some heat.

Professional enclosures will draw outside air ducted for the engine cooling and exhaust that air as well to the outside.

A short run won't be any big deal but extended running calls for managing the combustion air and the cooling air and then further venting the space with a decent size fan. In an enclosed small generator housing, say liquid cooled, cold air is pulled into the housing, across the gen end, past the engine through the fan with the fan pushing the air through the radiator, which is sealed well around all sides, then out the top of the housing. Exhaust is usually insulated and runs directly to the outside. Make your shed a copy of that and it will work great!

Also consider the winds and location of vents. Best for hot stuff to go out the top and cool intake at the bottom. This avoids a wind situation where hot exhaust air gets sucked back in the intakes.

BTW an open box of mothballs will keep all pests out.

I would love to make a gen shed out of concrete block. It would be very quiet if everything discharged out the top.

 

[robkiller]

I am placing a vent at the top to let heat escape. I am hoping there is positive pressure to push the heat out. The exhaust is already vented but I think the blow by that leaks around the engine will help that. If not I have found a 1600 cfm fan I can use.

 

[gimpyrobb]

Sounds like a good plan to me.

 

[ETN550]

I think that will work good. The important thing is to load it heavy and keep an eye on it. I use one of those $29 infrared temp guns with the laser sight from Harbor freight to check a variety of temps on the engine and exhaust manifold, intake, etc. Run it normal with good load to get a baseline then when its in the enclosure you will know how well it all works. Remember these units have a pretty high spec in tolerance for temperature so even if it runs hotter than normal in your standard environment, which it might, it could be well within spec and perfectly okay. Diesels tend to like heat anyway!

Post up some pics as you go. We would love to see it.

 

[storeman]

As you can see, mine are in an enclosure with exhaust vented. Since I built the enclosure haven't had a need to run them. Also since the picture was taken, the 002A on the left has been replaced with an 002A in an ASK and the 002A on the right has been replaced with an 003A.

If need arises, I plan to open doors as necessary and plug a box fan into the convenience outlet.
Jerry

 

[dangier]

"BTW an open box of mothballs will keep all pests out."

What is the secret to keeping mice out of wiring? I tried a box of mothballs in the boat cabinets and the mice chewed the box and incorporated the cardboard and a few mothballs into the nest.

One of my 02a's is going to be installed under a high deck sitting on crushed rock. Afraid that mice are going to make homes throughout if I cover it with a canvas. Don't want to leave it uncovered as I have a gravel state road close and the dust goes everywhere. Suggestions?
David