# Enclosing a Shop-Vac: danger of burning up motor?



## xvimbi (Sep 29, 2009)

Hi - I'd like to make a small, rolling dust collector consisting of a Lowe's Shop-Vac and a Dust Deputy. I've seen some people put their shop vacs in enclosures to cut down on noise and was wondering if anyone here has experience with such a setup. In particular, I am worried about overheating the motor. That possibility has been mentioned in discussions about enclosed shop vacs, but I haven't found enough descriptions of real-world experiences to come to a good conclusion. Any input appreciated.

Thanks so much! MM


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## Gene Howe (Jul 10, 2007)

Make the box 3" bigger all around. Maybe 4-5 " from the top. Leave the bottom open, of course, making two (or 3) sides a couple of inches longer so as to give yourself a cooling vent. 
I've seen the boxes lined with insulating foam and they seem to work ok. Sure cuts down on the screaming.


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## MikeMa (Jul 27, 2006)

I have been thinking about this as well. Two things I was thinking was making one side of the enclosure with plenty of air holes. Also each shop vac has intake and blower connection. Both typically are built to take your hose. Using PVC I would do direct vent of the blower connection. This would likely keep the shopvac from over heating.


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## xvimbi (Sep 29, 2009)

Thanks for the fast input!

One can get pretty fancy with these enclosures. Like this guy who uses a baffled air intake: http://www.ridgidforum.com/forum/showthread.php?p=162137#post162137

Insulating foam sounds like a good idea, but it will make efficient cooling even more important. I like the idea of running the direct vent out through a pipe.

Thanks again! MM


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## Gene Howe (Jul 10, 2007)

Venting the exhaust is a great idea, but IMO, you'd still want some circulation.


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## malb (Sep 15, 2008)

There is a significant drop in motor RPM with these units between running without hose and running with hose connected. This suggests that there is a fair degree of flow resistance in the hose assembly. 

My guess is that running a primary suction hose to a cyclone, then a secondary hose between the cyclone and vac will increase the flow resistance further. Adding a third hose for outlet ducting may well choke the thing to the point where there is insufficient air flow to cool the motor (or collect dust). 

The primary cooling is airflow around the motor, the more you restrict the airflow, the harder the motor works and the more heat it generates and the less cooling there is for the motor, potentially leading to a motor burnout or fire hazard.

Shop and other vacs may come with hose adaptors for the vacuum and blow ports but generally only come with a single hose. To my mind, this suggests that they are designed to work with a single active hose connection.


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## Cochese (Jan 12, 2010)

Why not try a muffler first?

Genuine Ridgid Vac Noise Muffler (72927) Part VT2525 low prices at TotalVac.com


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## Gene Howe (Jul 10, 2007)

I have one I'll give ya!
My experience is that they muffle only slightly.


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## xvimbi (Sep 29, 2009)

malb said:


> There is a significant drop in motor RPM with these units between running without hose and running with hose connected. This suggests that there is a fair degree of flow resistance in the hose assembly.
> 
> My guess is that running a primary suction hose to a cyclone, then a secondary hose between the cyclone and vac will increase the flow resistance further. Adding a third hose for outlet ducting may well choke the thing to the point where there is insufficient air flow to cool the motor (or collect dust).
> 
> ...


Good point. That may explain why the guy in the video referenced above went to the trouble to make an elaborate air intake baffle system. I guess I'll simply have to give it a try and see how hot things really get. MM


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## BigJimAK (Mar 13, 2009)

"Using PVC I would do direct vent of the blower connection. This would likely keep the shopvac from over heating."

The primary source of hot air doesn't come from the suction and discharge ducts themselves , but from the motor cooling fan (that on mine exhausts up through the top of the vacuum). Unfortunately that's also the source of most of the noise. 

I'm following this thread though cuz I'd love to have a quiet vacuum too, short of buying a $400 replacement!


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