Should I Worry About My Vacuum Overheating In Its New Home?

[Doris]

So I finally got on with it and have built myself a enclosure for my very noisy vacuum. I took a old filing cabinet my neighbour was chucking out and reduced it in size but kept the drawer as a way of accessing the hoover to save me having to mount hinges etc onto chipboard.

Here's a photo of it mid build. I then added a sort of seal around the drawer edge where it met the cabinet and the hole for the hose to make it more airtight. I put it on wheels as well so it wouldn't vibrate as much.

The noise has been greatly reduced but upon using it for about half an hour I found that the sides of the cabinet where getting a little warm. I was hoping to put a layer of insulation on the outside of the cabinet (I haven't added at all yet) to reduce the noise down further but wonder if this is such a good idea now as it seems to be getting quite warm inside as it is.

I was wondering if over members who had done this had the same issues or had found a way of minimizing the heat building up inside.

 

[shed9]

The idea is to baffle the sound not hermetically seal it. The vac's motor will need airflow to keep it working within its own parameters. Even the 2 and 3 stage motors that feed the air via the input still exhaust the warm air so if kept boxed up it will always run too hot.

Think of a car exhaust, it doesn't seal the air to stop the noise it runs it through several baffles / channels to slow it down and remove the sound energy from it.

 

[sunnybob]

you need exit airflow. take a look at my pics again, the air goes down below the machine, and then flows over and under a set of full width baffles before exiting at the front of the cabinet.

If you imagine a horse racing course with jumps viewed from the side, and then put another set of jumps above those but evenly spaced between the lower ones over half the vertical height. From the side view, the air has to lift over the first one, duck under the second one, lift over the third one, duck under the fourth one, etc. etc. This slows the air. Thats all you have to do, is slow the air down.

 

[rafezetter]

you need exit airflow. take a look at my pics again, the air goes down below the machine, and then flows over and under a set of full width baffles before exiting at the front of the cabinet.

If you imagine a horse racing course with jumps viewed from the side, and then put another set of jumps above those but evenly spaced between the lower ones over half the vertical height. From the side view, the air has to lift over the first one, duck under the second one, lift over the third one, duck under the fourth one, etc. etc. This slows the air. Thats all you have to do, is slow the air down.

For decibel reduction, speed reduction of the sound wave is only part of an effective solution. It also helps if the gap for the air is only 1/4 the size of the baffle - larger baffle and smaller gap increases the sound reduction via speed reduction from angular momentum, the distance it has to travel (sound waves lose effectiveness over distance as every knows) and the surface area for the sound wave to encounter and be "absorbed" (not the correct term but accurate enough). Doing all this increases the decible reduction so requires less baffles and space.

If you really wanted to maximise effectiveness, you can arrange the baffles so that thay are not parallel but offset in angle from each other to reduce angular reverberation, and adding a pad of dense sponge to the baffles on either side will also increase sound reduction.

All of the above will mean you can make baffles that will increase the inflow and exhast capacity to run cooler without increasing the sound decibels.

a google on "silencing compressors" will bring up a whole array of answers very similar to the above with pictures etc to follow that will allow the vac to breath easily without overworking the motor yet still significantly reduce the effective decibel volume.

this youtube has sort of the right idea, but hasn't taken it anywhere near far enough so you might wish to read my comments at the top to get the best from this design.

https://www.youtube.com/watch?v=JjqXeAhCp3o

 

[sunnybob]

There are a couple of designs on you tube that look like front room furniture, using anechoic foam everywhere, and not far short of the size of a sideboard.
I went with a quick and dirty approach on my unit. Box made of 22mm MDF , straight pieces of ply, every inside surface covered with loose blanket. While not silent, the loudest noise is the vacuum whooshing towards the cyclone. The baffles do overlap by about a third of the height.
And the whole thing took half a day and £20 to build.
Result! (g)

 

[rafezetter]

You're right that some of them are monstrocities, but I thought I had linked one that was fairly small and compact and with a few alterations could be even quieter.

 

[Emanuel]

So I finally got on with it and have built myself a enclosure for my very noisy vacuum. I took a old filing cabinet my neighbour was chucking out and reduced it in size but kept the drawer as a way of accessing the hoover to save me having to mount hinges etc onto chipboard.

Here's a photo of it mid build. I then added a sort of seal around the drawer edge where it met the cabinet and the hole for the hose to make it more airtight. I put it on wheels as well so it wouldn't vibrate as much.

The noise has been greatly reduced but upon using it for about half an hour I found that the sides of the cabinet where getting a little warm. I was hoping to put a layer of insulation on the outside of the cabinet (I haven't added at all yet) to reduce the noise down further but wonder if this is such a good idea now as it seems to be getting quite warm inside as it is.

I was wondering if over members who had done this had the same issues or had found a way of minimizing the heat building up inside.

Just as everyone already said, Yes, you are risking setting everything on fire. You would need a big whole in the box for the air to circulate.
Wouldn't it have been less expensive to just buy a new vacuum (a less noisier one)?

 

[sunnybob]

Any good vacuum is noisy. In this case, it would be simplest to make a hole in the back of the roof of the cabinet and build the baffle box over the top of the thing.

 

[Doris]

So I should build a baffle at the top rather than the bottom? It would be easier to change if it was at the top to be honest.

 

[sunnybob]

Doesnt matter where it is. Mine was on the bottom because I wanted the height to match the cyclone. cut about a quarter of the top out at the back, and then make your baffle box to sit over it.

 

[Emanuel]

Any good vacuum is noisy. In this case, it would be simplest to make a hole in the back of the roof of the cabinet and build the baffle box over the top of the thing.

All vacuums make noise, indeed, but some are more tolerable than others. The electrolux ones seem to be quieter http://www.vacuumsguide.com/quiet-vacuum-cleaners/