DC Room

[Andy London]

For those with a dedicated DC room, or any opinion/feed back appreciated. I have my cyclone installed in a DC room that is 10' X 6', I have a filtered return that is 20" X 24" which I thought would be big enough, just furnace filters so there isn't much resistance. However when the cyclone is running, if you were to open the door, the door will push into your hand, not just a little quite a bit... which is not a good thing...any thoughts?? I have a wood stove and a pellet stove, the pellet stove vents outside but the idea of negative pressure in the shop concerns me, if it is fact there...Is there an simple way to tell other than the door test?

Thanks a bunch

Andy

[Steve Cox]

If your cyclone is doing its' job, why the need for the filters? I would think the area of the return is plenty so maybe the filters give more resistance than you think? First thing I'd try is to remove the filters and see if your door test functions the same. Let us know the results of that and then we'll have more suggestions.;)

[Jim O'Dell]

The open door has to be less resistance than the filters, so it's normal that the air would push through the door opening, taking the door with it at first. Open the door about 8" and see if the door continues to be pushed open. I'm guessing it probably won't. Enough open area for the air speed to slow down. But the big thing is the air (through the filter or through the open door) is travelling back to where it came from...the shop. I don't think this will pose a problem for you. Now, if you were venting the air outside, and were opening an outside door and the air was pushing that door into your hand, THAT would be a problem. Jim.

[lou sansone]

hi andy

I am not an expert in air handling, but just back of the envelope calculations show that the size of the opening is too small..here are some thoughts

20 "x 24" = close enough to 4 sq feet of surface area

figure that your collector is 1600 cfm ( maybe 1200 ) that means that you have a velocity of 400 fpm. that is pretty high. General rule of thumb for spray booths is 100 fpm. You are at 3 or 4 times that amount. The air is going to feel like it is rushing past you. You would need to have at least 4 times the surface area to even come close to the draft on a spray booth.

Just some thoughts ... others with more expertise please join in

lou

[Jim Becker]

I agree with Steve, you don't need the filters...but you should baffle the return to reduce direct noise transmission. Be sure that the area of the return is at least the same area as the 8" blower outlet, but I'd suggest twice that for zero restriction.

[Andy London]

I agree with Steve, you don't need the filters...but you should baffle the return to reduce direct noise transmission. Be sure that the area of the return is at least the same area as the 8" blower outlet, but I'd suggest twice that for zero restriction.

I guess the idea behind the filters was not so much to filter the air coming back, but to do as you note, baffle any noise. That being said this unit is so quiet that the noise is not an issue so I removed the filters and now have a nice big hole in the wall:eek:

I have a buddy that is a blacksmith and makes artsy stuff with metal, I'll get him to make me some type of grate.

The install of the Gorilla is now complete and I am beyond impressed and amazed at the suction. I returned my LV 4" steel gates and ordered 5" ones which should be here later in the week, I used a few 6" gates at tools where I could build my own hoods, even with the old plastic gates leaking I have amazing suction at the tools. Where I noticed the biggest difference is the CMS station where I have a downdraft type table under the saws, hardly and dust escaped which is great as I spend so much time there cutting frames and dust has always been an issue....Sure am glad that project is done.

Thanks for the feedback!

Andy

[Allan Johanson]

Excellent Andy! I'm very happy for you that the Gorilla is working out. I still haven't cut the hole in my bench for the SCMS hood, but I think I'll stop analyzing it to death and just get on with it.

Paralysis by analysis....that's me! :D

Have fun breathing easy. ;)

Take care,

Allan

[Alan Tolchinsky]

Andy I have the same set up but with a smaller DC. I have the same experience with the door moving except I have no vent area cut out. I just leave it open a crack.

It seems to me that if you had enough return area in the door that it wouldn't move at all. If it was the correct size then all the return pressure would go through the filters and not move the door. For a rough estimate of additional return area I would let the door open to where it wants to go and then measure the amount of space that's in the opening. Like I said this may be crude but it gives you an idea. Sounds like an awesome DC. Watch you don't get sucked into it. :)