Dc under floor

[Dave Norris]

Hi Everyone,
I'm about 6 weeks away from breaking ground on a new shop. It's going to have a crawl space with a wood floor, and be 36 x 24, with ten foot ceilings. One of my main goals is to get the dust collection under the floor, and DC itself outside. My DC is a Clearvue, and I currently have s & d plastic pipe, but I'll either need to buy more, or switch to a different pipe. I've been thinking about it a lot, and I think I definitely want to put the pipe inunder the floor when the contractor frames the floor. I'd like to use as many 45 degree bends as possible to avoid restricting airflow. So, for you folks who hve your DC run under the floor;

1. How do you have the pipe come through the floor? Does it come straight up through, or does it come up at a 45?

2. How do you have the run to your DC? At some point the pipe needs to drop down from the DC to run under the floor, so how long do you have the run from the DC itself to where it turns down? Seems to me in the literature I saw somewhere that you want as long a run there as possible?

3. Does anyone have any pictures of how they have their system set up they might share?

Thanks for any help you can offer.

[Jeff Tobert]

1)I have the ducting in the concrete floor. I ran the ducts straight up through the concrete at 90 degrees, although you could certainly leave a 45 and come up through, depending on what you need after you come out of the floor. You have to remember that you lose static pressure with every turn of the pipe that you do, and 45's give you better flow than 90's. I have a 3 hp cyclone and run my main 8" duct straight down the middle of the shop with 45's off to different branches all underneath the concrete. It still pulls all the air I need even with the 90's.

2) My main line duct comes up out of the floor for hook up to the cyclone at 90 deg. I had to position the cyclone to match the floor, and that takes some planning, but you can do it. It comes into the collector at 90 degrees and the run is about 5' up. Ideally you want the main coming straight into the collector, but this won't be possible unless the collector is at floor level. Even though this is not the best in terms of airflow, it still works because my cyclone is powerful enough. A few bends in the main line is still better than having visible ductwork that gets in the way IMHO, and that is why I chose to go in the concrete.

In terms of materials, I used Spiral metal pipe coated with pvc from Marstan HVAC. Wider range of sizes than pvc, and still good for use underground.

[Robert Reece]

I don't completely have my system hooked up yet, so no pictures yet. I have a hybrid above/below system. Before I poured my concrete slab, I put some pipes underneath. I came up from underneath with a sweep elbow (I had to order them from McRey Distributing in South Carolina - great people - do a search for them here and you'll find their information).

The entry point under my slab is about 10' from the dust collector. I have a couple of wyes in that 10' run to pick up tools that are in that area using overhead drops. I also have a couple of 22's in that run and a short piece of 6" flex to help me get level from that 15 degree sloped intake chute.

[Dave Norris]

Thanks guys. I was starting to get a complex... I've never seen a post sit for 24 hours without a reply...

[Larry Fox]

Here is a link to some pics of mine. I went up high because I am space constrianed and I don't like having things underfoot.

[Steve Clardy]

Mine is in concrete.
I brought all the inlets straight up.