Duct for small blower fan?

[jeeppilot]

I'm working on an idea for my Son of a Fermentation Chiller. I didn't build it using the chambers for the ice bottles as the size would allow me to house (2) fermenters. The chamber will sit right next to my upright freezer which I plan to cut a hole in the side and use a blower fan and duct to move cold freezer into the chamber. A Brewpi will control the blower fan.

Here is the fan I have.

https://www.amazon.com/dp/B00B2ARV22/?tag=skimlinks_replacement-20

The exhaust is 1x1.25 inches. Any ideas for ducting and how to fit it all? A round hole in the freezer would be easiest, but that means adapting a square to a hole.

 

[NeoBrew]

I know how it goes when you get a DIY idea in your head and you just want to see it happen. So I am reluctant to meddle in your business, lol. Lord knows I've followed my own share of ideas!

I think you are probably asking for trouble by using the cold air from the freezer. There will be lots of humidity and condensation to deal with. In order to get air out of the freezer, you will need to provide some relief and let warm air into the freezer. This is going to cause lots of frost to form.

Have you considered turning your idea into a glycol chiller? You could put a reservoir of glycol in your freezer and pump it on demand into a coil in your chamber. You could even wrap a coil of copper around your fermenter and get more direct transfer right to your beer. You will still have to drill some holes in your freezer, but you will only need two smaller round holes for the tubes/pipes.

 

[jeeppilot]

I know how it goes when you get a DIY idea in your head and you just want to see it happen. So I am reluctant to meddle in your business, lol. Lord knows I've followed my own share of ideas!

I think you are probably asking for trouble by using the cold air from the freezer. There will be lots of humidity and condensation to deal with. In order to get air out of the freezer, you will need to provide some relief and let warm air into the freezer. This is going to cause lots of frost to form.

Have you considered turning your idea into a glycol chiller? You could put a reservoir of glycol in your freezer and pump it on demand into a coil in your chamber. You could even wrap a coil of copper around your fermenter and get more direct transfer right to your beer. You will still have to drill some holes in your freezer, but you will only need two smaller round holes for the tubes/pipes.

I hadn't thought about that. I am however very tight on space when I have two fermenters in there along with my blowoff setup. I was going with this idea mostly from an efficiency and "less is more" in terms of equipment standpoint.

Does it make any difference regarding the condensate that the freezer is my keezer so it is typically at 40F? It's a very old freezer and the seal leaks like a sieve so I already have some air relief and while I don't ever have frost I do have water accumulate at the bottom of my freezer.

 

[jeeppilot]

On a separate note, shortly after posting this of course, I came up with a simple solution. I'll use 2 boards in a T-shape, one with a 1.5" hole and the perpendicular one to mount the fan. To that hole I'll insert PVC pipe wrapped in insulation as the duct and seal the PVC and the the fan to the board with silicone.

On that note, I'd like more discussion on NeoBrews mention of the humidity and condensation from the 40F air making its way into the chamber. I'm not dissing his stance on the issue, just wondering if there is a clear consensus on that being a problem.

I'm okay having condensation in the keezer, but the chamber's foam board may not hold up over time.

 

[NeoBrew]

I didn't realize it was your keezer. If you used water that would be very similar to the setup I tried a while back. There is a thread on that here.

I eventually moved away from that because managing the water and hoses was just too much trouble. For $50 I got another chest freezer from Craigslist that didn't require all the messing around. I use that as a straight up fermentation chamber now.

I have no experience with your ducting method. Since the keezer is not freezing you won't have frost problems. If you don't mind managing the condensation you might like the solution.

 

[jeeppilot]

I didn't realize it was your keezer. If you used water that would be very similar to the setup I tried a while back. There is a thread on that here.

I eventually moved away from that because managing the water and hoses was just too much trouble. For $50 I got another chest freezer from Craigslist that didn't require all the messing around. I use that as a straight up fermentation chamber now.

I have no experience with your ducting method. Since the keezer is not freezing you won't have frost problems. If you don't mind managing the condensation you might like the solution.

It's a solution for the time being. I have ideas I like that use the chamber that I couldn't do with a chest freezer. I think it'll be okay, since I don't mind the water in the freezer, and since blowing cold air into a warmer environment should do the opposite of condensing water out, I think my chamber will remain dry. Once I get it done I'll let everyone know how it works! [emoji482]