Easy & Cheap Stainless Vent Hood

[schematix]

This is the only thing in my brewery that isn't stainless.View attachment ImageUploadedByHome Brew1423113047.444067.jpg

 

[stickyfinger]

didn't want to tarnish it

nice pun!

 

[BrewWho]

That thin stainless bowl was a bitch to cut. Ate up 3 jigsaw blades and took about 15 minutes. Even my nice cobalt step bit was having a slow time getting my pilot hole cut.

I thought about using a plastic tote, but I have built a stainless steel shrine in by basement and didn't want to tarnish it

What blades were you using?? I think the only thing i could find was a fine tooth wood blade and it ripped through it in no time!!!! Step bits seem to have trouble with ss, at least that was the case when putting holes in my keg.

 

[Minbari]

That thin stainless bowl was a bitch to cut. Ate up 3 jigsaw blades and took about 15 minutes. Even my nice cobalt step bit was having a slow time getting my pilot hole cut.

I thought about using a plastic tote, but I have built a stainless steel shrine in by basement and didn't want to tarnish it

I used a bi-metal jigsaw blade on mine. Took about 5minutes

 

[stickyfinger]

maybe it depends on the gauge of the pot, the quality of the bowls, etc. what is the approximate size of the flat, bottom part of those 30 qt SS bowls? I assume it is at least 7 or 8"?

 

[schematix]

I used Bosch bimetal fine tooth (17-22 TPI?) jigsaw blades and cut a 5 7/8" diameter hole. The bowl bottom was right at 8".

My step bit cut the Blichmann kettles like butter. On this mixing bowl it was throwing sparks and just didn't want to go.

 

[stickyfinger]

was the bowl flexing under the pressure of the bit? i fond that can cause a lot of problems unless your bit is really small. then, it will kind of pop through the metal as it flexes back.

 

[schematix]

Yep that's exactly what was happening.

 

[h22lude]

Glad I found this thread. I just put together my e-BIAB system. Right now I own a townhouse but will be buying a house relatively soon so I didn't want to do anything permanent. Anyway, I will be brewing in my bathroom. The closest window is about 15 feet away. I use a 5500W element. Would this fan work with that much duct?

http://www.amazon.com/dp/B002EC01XS/?tag=skimlinks_replacement-20

And since it is in my bathroom I will need to figure out how to build a stand for it since I can't mount it on my wall or ceiling. I like the bowl idea but a plastic box may be easier to create a stand for. Could just attach a leg to each corner and be done.

 

[stickyfinger]

Glad I found this thread. I just put together my e-BIAB system. Right now I own a townhouse but will be buying a house relatively soon so I didn't want to do anything permanent. Anyway, I will be brewing in my bathroom. The closest window is about 15 feet away. I use a 5500W element. Would this fan work with that much duct?

http://www.amazon.com/dp/B002EC01XS/?tag=skimlinks_replacement-20

And since it is in my bathroom I will need to figure out how to build a stand for it since I can't mount it on my wall or ceiling. I like the bowl idea but a plastic box may be easier to create a stand for. Could just attach a leg to each corner and be done.

I bought that exact fan recently. I haven't installed it yet, but it can really push some serious air. I think it would work perfectly for your application. It comes with a mounting bracket on the side that you can screw into a frame of some sort. You could just put four 2x4s together as legs and screw into them through a plastic tub or something and put the fan on top of that resting on the tub and then put an elbow and flexible duct on the fan. should work fine.

 

[h22lude]

I bought that exact fan recently. I haven't installed it yet, but it can really push some serious air. I think it would work perfectly for your application. It comes with a mounting bracket on the side that you can screw into a frame of some sort. You could just put four 2x4s together as legs and screw into them through a plastic tub or something and put the fan on top of that resting on the tub and then put an elbow and flexible duct on the fan. should work fine.

My only worry is condensation building up in the duct. My bathroom is attached to my bedroom which is where the window is. So the duct would start above my pot, go down to the floor and then up to the window. I would think water could build up at that low point. Not sure if that is a problem or not.

 

[stickyfinger]

I assumed your window was in your bathroom, but 15' would be a lot of bathroom i guess! i don't know. you could just try it and see what happens. you're going to have a house soon and will use the fan for sure and probably some of the duct, so why not give it a try and see. you could always poke a drain hole in the duct and let it collect in a bucket if it is a problem

 

[schematix]

Worst case when you're done tilt the duct and drain it. It's not permanent and with occasional water exposure nothing terrible is going to happen.

 

[h22lude]

I assumed your window was in your bathroom, but 15' would be a lot of bathroom i guess! i don't know. you could just try it and see what happens. you're going to have a house soon and will use the fan for sure and probably some of the duct, so why not give it a try and see. you could always poke a drain hole in the duct and let it collect in a bucket if it is a problem

It is 530CFM which is almost double what I would need. I assume the extra power would be able to handle the added duct length.

Worst case when you're done tilt the duct and drain it. It's not permanent and with occasional water exposure nothing terrible is going to happen.

Good point. Just drain and let dry.

 

[stickyfinger]

I don't know if my calcs. are correct, but assuming you have the equivalent of 3 elbows and 15' of straight duct run (using 4" duct), you would generate a static pressure of at least 0.398 in.H20 with some thrown in for the hood itself. The Tjernlund M-6 is still good for 460 CFM at that pressure.

Maybe you could mount a plastic tub over the BIAB and then poke a hole in the side, mount the fan inline on a little box or something, and then go around and out your bedroom window. it should work fine.

 

[h22lude]

I don't know if my calcs. are correct, but assuming you have the equivalent of 3 elbows and 15' of straight duct run (using 4" duct), you would generate a static pressure of at least 0.398 in.H20 with some thrown in for the hood itself. The Tjernlund M-6 is still good for 460 CFM at that pressure.

Maybe you could mount a plastic tub over the BIAB and then poke a hole in the side, mount the fan inline on a little box or something, and then go around and out your bedroom window. it should work fine.

If mounted on top I would only need one 90° elbow. The duct would go down from there, lay on the floor and then up to the window. Where my brew stand is, it is basically a straight line out the bathroom door to the window. The duct obviously wouldn't be all on the same level. From the elbow it would drop down to lay on the floor then back up to the window. The window is big, probably 2 feet from the floor.

 

[stickyfinger]

even better, i just threw in the 2 extra elbows as a worst case scenario for your floor dip arrangement.

 

[schematix]

sticky - are you always assuming a constant effective length for every elbow or are you varying it based on type and the velocity?

the right way to determine the flow you get is to first get the pump's static pressure vs CFM curve. Then you need to solve the piping systems static pressure for several CFMs and connect the points on that curve. Where the 2 curves intersect is the actual CFM you'll get. The trick here is that for every CFM and fitting you have a different velocity and different equivalent length, and a thus different static pressure loss.

 

[stickyfinger]

I'm using this document to estimate SP:

http://custom-wheels-blowers.centralblower.com/Asset/Determining-Static-Pressure.pdf

6" elbow is always 12' linear duct equivalent. there is no number for 4", so I estimated at 9'.

How do we solve for SP of ducting as a function of CFM? My calcs don't consider CFM until the fan curve. Do you have a good reference or calculator?

 

[schematix]

This is the document I was using. It is very long and has a lot of details. Between that and now being sick I haven't had the time to get through all of it, but it looks thorough.

http://web.fscj.edu/Mark.Bowman/handouts/ACCA Friction Rate Reference Chart.pdf

Note that for most fittings and pieces they gave an "EL" or equivalent length at a given velocity. There is a also a formula to calculate the EL if you have a different velocity.

 

[NewBrewB]

This thread got way more technical than necessary.

This is not some 24x7 HVAC system. At the most, you would run this fan for a 90-min boil. A big fan meant for steam will push the air fast enough that it is outside the building before it starts to condense/drip.

The Original Post was about making a cheap and easy solution for venting steam.

Let's not overcomplicate it and intimidate home brewers who click on this thread because of the title.....just my 2 cents.

 

[stickyfinger]

I wonder which of these online calculators is reliable? The first one seems to be good, as you can calculate the static pressure for each fitting/run in your system at a given CFM and then add them up and calculate your system SP:

https://www.google.com/url?sa=t&rct...VeO0Tz_ZQuLcAKZ5A&sig2=5QNptEF6m9LuzIhMA44glA

The second is simpler to use, more limited obviously.

http://bry-air.com/resources/utilities/static-pressure-calculator/

Both give much higher SP than estimating them using the page I was using before that didn't take into account CFM in the SP calculation.

There's also one here from a woodworking guy's calculations for dust management that could be good:

http://www.billpentz.com/woodworking/cyclone/staticcalc.xls

They all are pretty close for the 6" duct, but they vary some when I put in 4" duct.

I guess the proof is certainly in the pudding. Buy big and you probably don't have to worry unless you are doing a lot of crazy turns and long runs.

 

[stickyfinger]

This thread got way more technical than necessary.

This is not some 24x7 HVAC system. At the most, you would run this fan for a 90-min boil. A big fan meant for steam will push the air fast enough that it is outside the building before it starts to condense/drip.

The Original Post was about making a cheap and easy solution for venting steam.

Let's not overcomplicate it and intimidate home brewers who click on this thread because of the title.....just my 2 cents.

Yeah, you're totally right. Let's bag this discussion on this thread. If anyone is interested, we can start up a discussion of ventilation static pressures somewhere else! It's totally unnecessary to do these calculations for your system. If something worked for someone else, it will probably work for you. I think most people realize that.

 

[schematix]

Buy bigger is always the answer that gives the best result... Until someone wants it cheaper.

I can agree to take the technical discussion to another thread.

I would say in summary:
-don't use the super cheap inline fans. You need the big blowers. 4" minimum. 6 or even 8" preferred.
-limit elbows
-minimize distance if possible
-expect some condensation. Just dry it out when you're done.
-speed control is probably unnecessary unless you buy the larger blowers and have a huge excess of power.

Am I missing any other key points ?

 

[jsprinceiii]

Buy bigger is always the answer that gives the best result... Until someone wants it cheaper.

I can agree to take the technical discussion to another thread.

I would say in summary:
-don't use the super cheap inline fans. You need the big blowers. 4" minimum. 6 or even 8" preferred.
-limit elbows
-minimize distance if possible
-expect some condensation. Just dry it out when you're done.
-speed control is probably unnecessary unless you buy the larger blowers and have a huge excess of power.

Am I missing any other key points ?

Make sure to have a source of "Make-up Air".
This is not a technical requirement, instead is a "Health/Life" requirement.
Over the years, the rule of thumb was add if over 300CFM.
With todays houses, I would recommend it with as small as 150CFM.
Carbon Monoxide is not something to play with, and in most homes, without a
source for make-up air, you will be pulling air from your furnace/water heater
chimneys/vents.
Maybe even add a CO detector near the brewing area room.

 

[theck]

Make sure to have a source of "Make-up Air".
This is not a technical requirement, instead is a "Health/Life" requirement.
Over the years, the rule of thumb was add if over 300CFM.
With todays houses, I would recommend it with as small as 150CFM.
Carbon Monoxide is not something to play with, and in most homes, without a
source for make-up air, you will be pulling air from your furnace/water heater
chimneys/vents.
Maybe even add a CO detector near the brewing area room.

Would a simple fan suffice? Would it be best to open a window for example? or can it be just in the room?

 

[jsprinceiii]

Would a simple fan suffice? Would it be best to open a window for example? or can it be just in the room?

That is a hard question to answer.
However..
Needing to go "Big" is not necessarily the correct answer.
Opening a window, should work..

Safety should be our #1 requirement, with easy and cheap the second.
Every house would be different.

Research..Here is an interesting read that I refer many people to..
http://www.abe.iastate.edu/extension-and-outreach/carbon-monoxide-poisoning-ventilation-aen-209/

Make-up air, not only increases efficiency of ventilation, it safely allows inbound fresh air back into a room, reducing negative pressure, or simply not pulling air from chimney flu, cracks in wall, ceilings, electrical outlets, leaky windows etc...

Many new homes are already designed with a 14" or larger makeup air source, however it is not a requirement.

I currently have a 390CFM fan venting 2 20Gallon kettles (back to back) no moisture, and over a 4 hour period, maybe a teaspoon of condensate on the hood. I have about $600.00 invested.
My family's safety trumped all.

 

[NewBrewB]

Electric brewing doesn't emit carbon monoxide. Don't most propane brewers do it outside?

 

[theck]

Electric brewing doesn't emit carbon monoxide. Don't most propane brewers do it outside?

I was wondering too, but think they are talking about the make up air and how it can cause issues with carbon monoxide?

 

[stickyfinger]

The issue is where your makeup air is coming from. If your chimney is the source of (unplanned) makeup air, you can pull in exhaust fumes and kill yourself.