DIY: Flow Hood and Heat Bomb

[wtoad]

I thought I would share my last two projects. Both have room for improvement, but both seem to work correctly.

[THE HOOD]
The hood is shelving/paint grade composite pine. Picked it up at Lowes relatively cheap. Doesn't bow badly and is of a good width so you don't have to join any pieces together. The whole thing is held together with finish nails and glue. Dimensions are 17"H X 16"W X 21.5"L. The internal working area is just shy of 12" deep. The filter is a true hepa held in place by a 1" wood sill/frame and sealed with a generous bead of silicone.

The fan box is of the same material and built to the dimensions of the fan, which was a bit large... It's held in place by gravity and kept from tipping or moving around by two biscuits at the base that seats male to female (see pics). The fan is a ventilation fan and really too strong for the application. Trouble is, with winter approaching, its next to impossible to find a fan. I regulate the flow with the towel - letting more or less of the prefiltered air out of the fan box to get the right flow through the hood. I hope to find a smaller barrel fan this spring and then make another fan box to fit the hood.

The piece of wood in front of the fan is an after thought - seems these ventilator fans create quite a vortex if the output is restricted. Suprisingly, the one piece of wood keeps the breeze at bay.

The work area is 3/4 shielded (to keep my bad breath out) by plexy glass hung on two small nails and kept from blowing outward by a rubber band.

[HEAT BOMB]
Hippie, I have you to thank for the initial idea on this one. The heater is a Jager (now made by ehiem, was Ebo Jager) 100W. The bottle is your standard Gatorade - in my case I like the orange flavor - so my bottle was orange. You may like blue or red - either will work also. I drank the Gatorade and now my bottle is clear. The seal for the heater/bottle is 3/4" Ethylene Propylene gasket from us plastics (Was part number 30670 a few years ago, $.64). The gasket and a little mineral oil make a tightly seated fit with no water leakage. The fit is tight enough to keep the heater firmly in the middle of the bottle even with it laid on it's side.

The crazy pipes coming out the top are for a later application of heating several chambers with their own heat bombs, but with only one 100W heater - the one pictured. This is accomplished with some airline tubing, three or four additional (smaller) bottles and two Aqua Lifter AW-20 pumps (About 3.5 GH each). The pipes are rigid airline tubing and held in place with silicone.

All in all I'm satisfied with the results. The flow hood is noisy, but I've had no contams thus far with GTG. The heat bomb is a dream, keeping my cabinet a steady 75 through out.

cheers and happy backyard building...

[~Hippie3]

nice work there

[golly]

Wow,, nice looking hood there Toad...Love the woodwork...

[llamabox]

Have you tested the flow hood over agar yet?

We were just talking about that type of fan in chat the other day, and we were not sure if it had the power to push through a HEPA.

[wtoad]

nah, haven't done the agar yet. I can only obsess over this stuff a little at a time or my wife gets crazy. I've currently reached my maxim on the "what she'll put up with chart" for a few weeks. But, as soon as she cools I will definitely give a try and see/tell what happens.

As for the strength of the fan, it sure can blow. The label claims 83 cubic meters a minute at 3300 rpm. I use the low side of the switch. The kind of nice thing about the fan (and I'm really not in love with the fan at all) is that it does move a lot of air, but doesn't seem capable of over compressing the air and damaging the hepa filter. In the end I get a nice, albeit loud, even and consistent flow.

Originally Posted by wtoad

I can only obsess over this stuff a little at a time or my wife gets crazy. I've currently reached my maxim on the "what she'll put up with chart" for a few weeks. But, as soon as she cools I will definitely give a try and see/tell what happens.

Wow... just like a page out of my own life.

Tell her without this hobby you may die. That's what I tell mine (with teary eyes), and she laughs and leaves me alone for another day.

[BuckarooBanzai]

You will live to be a much older married man if you don't hydrate poo in her Tupperware.

Not even worm poo, not even once.

Trust me on this.

Interesting design on the hood. I envy people who can do stuff like that with their hands. I mostly end up needing stitches when I play with power tools.

Very nice work btw.

[sandman]

wait what kind of hepa filter is that in the flowhood? Do you know the efficiency?

[wtoad]

Its a Hunter. 99.97%.

[JaR]

You will live to be a much older married man if you don't hydrate poo in her Tupperware.
Not even worm poo, not even once.
Trust me on this.

LOL Dont I know thats so true

Very Nice WTOAD!!!
Im interested in a flowhood and I may go this route once I find the correct fan.

[roksoc]

nice work on the hood.

[sandman]

Originally Posted by wtoad

Its a Hunter. 99.97%.

This is an innadequate filter for a flowhood. There is a reason that flowhoods use 5 7/8" thick 99.99+%@.3micron filters. The .02% of contams is alot even though it doesnt sound like it. You may be getting lucky right now, but your flowhood is not providing a sterile environment.


Im just saying this so newbies dont think that they can go buy a hepa filter from walmart, slap on a ventilation fan and start doing agar work. For not that much more you could have probably bought a real 5 7/8" 99.99%+ hepa and a real squirrel cage blower fan. I bet you spent as much on that nice thick ass wood then a real filter would have cost anyway. I bet you werent but about 50 bucks off from the real deal.

That being said that is some very nice work on the wood! Im very impressed!

Just for shits and giggles can we get a lighter test on the hood? With a bic lighter and not a giant propane torch?

[wtoad]

Yeah, I definitely understand that there are a bunch of particles streaming through my filter. I probably didn't educate myself on the notion very well before hand.

I looked up the part number of your filter.
3800-51 ULPA FILTER 24" x 48" X 3" $435.00

Nice filter.

Total cost of mine was around 210.00. Wood is cheap, probably $30 of the total cost.

I'd show you the lighter, but it would be a picture of a lighter with no flame. The fan blows it out, hence the *small* blow torch.

Regardless, it seems to be providing decent conditions for basic grain to grain transfers. Definitely could be luck.

I appreciate the close up on the part number. Looks like I can pick up a similar rated 12X12 filter from the same place for around 134.00. Seems a decent price - and with a few mods, my flow hood can probably accommodate the change.

As far as the fan, it seems more than capable of the task. And, from what I've priced online at grainger, it was considerably cheaper than a squirrel fan of similar measure. Now, increase the depth of the filter by 3 and I may have to post other wise.

[StroFun]

I too love your wood and that shit is the bomb.

[~Hippie3]

Originally Posted by StroFun

I too love your wood ...