24 replies to this topic

[MurCurY]

I'm finally assembling the parts for my flowhood.
I have a huge squirrel cage blower...think house furnace....and i'm going to rheostat it.

In the diagrams of most flowhoods....the fan is mounted on top of the unit. Is it a bad idea to mount it behind the unit blowing at the filter? Or maybe mount it on the side of the unit?

[Hippie3]

don't think it matters much
but on top takes up less table space

[MurCurY]

so where's the cheapest place to pick up a true hepa for this? I'm thinking....cheapest for most area. The fan is ginormous! 17"x17"x13".
I'm hooking it to a motor that runs it with a belt. I have to mount it to a piece of wood or something. I'll post pics maybe you guys can help me figure this out.

[LocoH]

Be Sure To Place Some Kind Of Screen Or Wire Over The Face Of The Squirell Cage. Better Safe Than Sorry. It Can Be Easily Screwed On From Sides.

[thebaldingeagle]

so where's the cheapest place to pick up a true hepa for this? I'm thinking....cheapest for most area. The fan is ginormous! 17"x17"x13".
I'm hooking it to a motor that runs it with a belt. I have to mount it to a piece of wood or something. I'll post pics maybe you guys can help me figure this out.

Try FILTERA.com. I dont know if thats the right address, but I'm sure that'll get you close. I got mine there 24x18. Phone # is 1 (218) 933-1100. I'm pretty sure that they have an 800# but I dont have it, sorry. The web site will though.

[MurCurY]

does anyone know what size fan you need to power this filter for a flowhood?
and i do have the right filter.....right?


HEPA Filters
12 x 24 x 5-7/8 (99.99% HEPA wood) $91.41

[kocos]

You want something along the lines of a 115V/60Hz, 488 CFM free air delivery, 217 CFM at .8" static pressure. This should work for a 12x24 inch HEPA unit.

[python]

might consider a metal framed filter IMO

[Myc]

I'm considering a flowhood build too.
Python, what is the rationale behind the metal frame opposed to the wood framed filter? Couldn't the wood frame just be sanded and coated with Verathane (or similar sealant) like the rest of the wood construction of the flowhood cabinet will be?

My main concern is the size of the filter face itself. Any one have experience with filters this small? The only ones I've ever seen are 24"x48" in industrial applications. I'm curious as to the effective working area in front of a 12" filter.

[dpwishy]

iv heard 12 x 12 is a nightmare to work with, way to small. 12 x 24 is good, but people keep saying if you want to make it right the first time, use a 24 x 24 filter.

[MurCurY]

So...just an update. Got the blower part. Ordering the filter today.
this is the fan i got...when i got it the top of the housing has a dent in it. doesn't impeed airflow...maybe adds some noise but it'll be in a box so not a huge issue.

Grainger Industrial Supply: Blower,495 CFM,115 V 4C445

i'm ordering this fan today....

12 x 24 x 5-7/8 (99.99% HEPA metal) $128.93
orering from
HEPA Filters


I'm looking at material for the body of the hood. any suggestions? I was thinking a thin sheet of premium grade plywood painted in gloss white would do very nicely. I'm trying to make it light enough that i only need me to move it :grin: my last venture would have needed 2 people easy to move just the blower. For the record....495cfm of air is ALOT less then I thought it was! i mean....it's alot of air...but...i thought the fan would be larger then it is.

[Myc]

Super Sweet Man!

You'll definately be able to move that hood by yourself.
Looks like we're progressing on this endeavor at the same pace.
Got my filter ( 30" x 52" HEPA) and fan ( 1/4 hp) on ebay in separate auctions.
Waiting on the blower right now.
Total cost: $163.00 Shipped (thus far)

Thinking the same thing you are on the hood body construction.
No need to pay for premium grade since you're going to paint yours too. Great minds think alike. Go with the low grade plywood (CDX). Sand it and paint all surfaces. Should work great.

Good luck and please keep us posted!

[Lazlo]

You can fill the cracks and holes in the plywood with Fast and Final before painting it. Hit the entire surface of the work area with F and F and a 4" blade. Takes a couple of minutes of filling, a few hours to dry completely, a couple of minutes of sanding and you have yourself a smooth as a baby's ass surface to paint in a few hours. Neatly caulk the joints after the surface is smoothed down too. High gloss paint also.

You could always formica the work area instead of painting it.

[MurCurY]

just ordered the filter.
I was thinking formica but that's a bit much. I'm going to get a gallon of Behr high gloss titanium white to paint it nice. fast and final....i'll look for that.
if i get the filter by friday this will go together this weekend.

[Lazlo]

It's great stuff. I use it when i'm prepping shelves for spraying. It's easy to work with and works fantastic. Just put some on the edge of the 4" blade and then drag the blade across all of the work area. What ever is low will fill up with the F and F. Don't put a skim coat of it on the whole area is where i'm trying to get at.

[Myc]

Excellent idea!
Thanks Lazlo!
Got some of that stuff around. Use it for exterior house painting to fill the little imperfections prior to painting. Makes for a baby smooth finish coat and gets rid of all the little pits and crevices where particles could collect and hide. Finish sand with 220 grit sandpaper or finer if you're a real freak (like me).
Plan to seal the joints with anti-bacterial caulk (all inside corners, filter to housing surface, etc.).

:thumbup:

[Lazlo]

It's the best stuff hands down for filling in shit. Nail holes, blemishes, exc. It's ability to shrink up when dry is minimal also. If you leave the F and F slightly crowned, when it dries it's perfect. A 1 time deal.

[MurCurY]

got the filter today.
I'm going to home depot for some wood.
How much plywood do i need to assemble this thing?....1 sheet....2? I've decided on hardwood plywood. A bit pricey....but it's VERY rigid for being relatively thin. And an oil based primer and High Gloss Ultra White Baer paint. It's going together over the next couple days and finished up on Sat.....

Just need some help with dimensions....

[MurCurY]

i decided i'm going to get 2 sheets....more then enough...and i can make a bookcase out of what's left. it's gorgeous wood. I'm going to use a 2' HO T5 floro for light. I decided on this design...only slightly different.
Lotte & Thomas Orchids
I'll keep this updated.

[MurCurY]

hoods together.....

on the filter there is an arrow indicating "flow direction"....is this direction important? I need the foam on the back side of the filter...not the front.