Thread: Another new shed build

Looking good, like the exhast fan. Appears like you have plenty of room, now, I'm sure that will change quicker than you expect. .
Be interested to follow your DC build.

Originally Posted by Brian45

Looking good, like the exhast fan. Appears like you have plenty of room, now, I'm sure that will change quicker than you expect. .
Be interested to follow your DC build.

The fan was a bugger getting up by myself, but I got there. It sucks a lot of air, so should do the job. Very nervous about the DC build, certain to make some rookie errors, but plenty of people here to hopefully keep me on the right track.

Started to build the DC cabinet. A quick question. I plan on making vent 600 x 600. Does this sound about right? Thanks

Originally Posted by Baddabing

Started to build the DC cabinet. A quick question. I plan on making vent 600 x 600. Does this sound about right? Thanks

That will be heaps - you could even go to 300 x 300.
The bigger you make it the more noise will escape, the smaller you make it the more back pressure it generates.

Originally Posted by BobL

That will be heaps - you could even go to 300 x 300.
The bigger you make it the more noise will escape the smaller you are it the more back pressure it generates.

Thanks Bob, didn't think about the noise. I will maybe reduce to 350 x 350.

Been quiet for a month. Been overseas and the missus has had me doing stuff around the house, so little time in the shed. Finally got the cabinet built, added a small bench and have started lining the walls. I ended up using formply. Since I am venting the cabinet externally, I thought formply would probably stand up the best if it got a little wet. I considered marine ply just for the paneling around the vent, but you need take out a second mortgage for it! Bloody expensive. Since I plan on hanging cupboards or a french cleat system off the walls, I wanted ply for the wall paneling. Formply proved a reasonably priced option. Bunnings has 1200 x 600 x 17mm sheets for $11, so $44 for the equivalent of a 2400 x 1200 sheet, which is $70. Seemed a no brainer to me. Putting R3.5 insulation in the walls as I go. Now I have to assemble the Dust Collector, H&F DC 7 3 hp. and work out ducting and final tool locations.
Cabinet.jpg

Originally Posted by BobL

That will be heaps - you could even go to 300 x 300.
The bigger you make it the more noise will escape, the smaller you make it the more back pressure it generates.

Hi Bob, thought I posted this question to you, but it doesn't appear so, so apologies if I have asked twice. I want to run an 88 degree angle almost straight out of the DC, so I can run ducting through the top of the cabinet. Otherwise I would have to run duct straight out through the doors which would be a real pita. I think I read somewhere that your suggestion was something like a minimum of a metre between junctions etc, so would a angle straight of the DC be a problem?

Originally Posted by Baddabing

Hi Bob, thought I posted this question to you, but it doesn't appear so, so apologies if I have asked twice. I want to run an 88 degree angle almost straight out of the DC, so I can run ducting through the top of the cabinet. Otherwise I would have to run duct straight out through the doors which would be a real pita. I think I read somewhere that your suggestion was something like a minimum of a metre between junctions etc, so would a angle straight of the DC be a problem?

Yeah its not going to help but if you can't do anything else you will have to live with it.

Thanks Bob

I have started running the DC ducting. Using an anemometer (cheapie off Ebay) I get 2400 cfm straight out of the dc. As seen from the photos, I had to run an 88 bend virtually straight off the DC to go up through top of cabinet. I tested the airflow at the junction you can see in the photos, and still get 2400 cfm. So far so good.
I will start making blast gates (swing type) this weekend, so I can install the gates as I go. There are a few pics below and a rough plan for the DC ducting. It is being run at around 2700mm from the floor, so well out of the way. Any thoughts or suggestions before I get too far ahead are most welcomed

DC Plan.jpg DC.jpg DC duct.jpg

Originally Posted by Baddabing

I have started running the DC ducting. Using an anemometer (cheapie off Ebay) I get 2400 cfm straight out of the dc. As seen from the photos, I had to run an 88 bend virtually straight off the DC to go up through top of cabinet. I tested the airflow at the junction you can see in the photos, and still get 2400 cfm. So far so good.

If you are using 6" ducting I find it very difficult to believe you are getting 2400 CFM - is it a propellor type anemometer?

Am getting about 78 db about 1m from the cabinet, but I have not sound proofed the doors yet, so hoping I can get this down to around 70 db or better. Not sure this is possible, as it seems a fair bit of noise comes from the duct work. May try wrapping it in insulation once I have finished if noise is an issue. Cabinet is airtight, tested the doors with a blower. No air coming out so happy with that. The vent is right behind the motor, and is 400mm x 350mm. Noise outside is quite low, around 60 db 2m from the vent (closest I can get to it), so hopefully the neighbours will not be too concerned.

Originally Posted by BobL

If you are using 6" ducting I find it very difficult to believe you are getting 2400 CFM - is it a propellor type anemometer?

Yes it is. At the junction you can see in the photo, I blocked the 45 degree and tested the straight section. The DC nearly sucked the unit out of my hand, it was really sucking. the 2400 was at about 50mm from the pipe

Originally Posted by BobL

If you are using 6" ducting I find it very difficult to believe you are getting 2400 CFM - is it a propellor type anemometer?

As stated, it is a cheapie off Ebay. I got it not so much to measure the CFM, because I have low expectations of accuracy. I wanted to measure the decline in performance as I added piping, junctions and flex hose. In particular, I want to see what I get at the machines. I assume that what I start with is what it is. Maybe what I can do is reduce the drop by minimisi9ng flexi & the need to reduce to 100mm where possible. Hope that makes sense.