Calling all exhaust experts

Have a friend who just built an indoor brewery and having some exhaust issues. Currently has two 8" inline duct fans pulling around 450 cfm. Looking to try and double the exhaust for under $100.

Here's the issues:
1. Ducting is 8" so needs to be an 8" fan

2. Money is an issue otherwise he would have went and bought expensive high flow fans already.

Any suggestions??

Those inline fans are bad. Try calling a few HVAC contractors asking for out of service blowers. I don't know if they trash them when they change out a system or not, but it's an idea.

Where's the fresh air coming from?

I am not an expert by any means, but I think a small adjustable fan with some extra ducting would work: Twin Window Fan. Depending on the dimensions of the space, I would run two 8" ducts to each fan; one push and one pull. These little window fans are nice because you can have one fan pull air in, and one side push air out all in the same unit. This unit is rated for 1000CFM, and you should get close to that with 8" ducts. Keep in mind if you use one side for intake and one for exhaust you will only get half that, and maybe a bit less since these fans are side-by-side in the same box.

That being said, I think you're best possible solution would be a whole house fan. I'm not sure what kind of burners you have for the brewery but I'd be worried about the CO buildup in the room. Those fans run about $200, plus wire and duct work but I think the end result would be very effective and definitely more safe.

Bobby_M said:

Those inline fans are bad.

Click to expand...

Why?

They just don't push the CFM I'd be comfortable with.

How does he have the fans staged? Two 8" ducts necking down to one or both fans in the same duct? The latter gives much higher flow.

My experience with cheap inline fans is they have badly designed blades that are also too small. That allows for a lot of backflow.

I'd also agree that one for intake and one for exhaust is a good idea.

There are others here who brew inside. I know you're trying to keep it cheap, but SERIOUSLY. You do NOT want to skimp on this. You could easily kill yourself and others if you don't ventilate properly....maybe even burn the house down. You can buy all the fan you'll ever need here:http://www.costco.com/Browse/Product.aspx?Prodid=11122519&search=fan&Mo=42&cm_re=1_en-_-Top_Left_Nav-_-Top_search&lang=en-US&Nr=P_CatalogName:BC&Sp=S&N=5000043&whse=BC&Dx=mode+matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:BC&Ne=4000000&D=fan&Ntt=fan&No=9&Ntx=mode+matchallpartial&Nty=1&topnav=&s=1 Keep in mind, CO/ CO2 are heavier than air and stay on the floor. Pull the noxious gases from the floor as well as the ceiling, as heat will cause them to rise. Send fresh air in from another location, so you get a nice "loop". Lastly, don't forget a carbon monoxide detector! That may be the only warning you get if you're in a dangerous situation. This stuff would probably cost you $150....totally worth it if you absolutely can't brew outside.