We’ve all been there, started our boil and everything is going smoothly and then drip…drip…drip. Yep the dreaded condensation from boiling liquid indoors. It’s on the walls, ceilings, kitchen cabinets…everywhere. It’s worse in the cold weather as the outside walls are cooler than the inside air. Since switching to electric brewing and moving brew day indoors it was the only downside to brew day. For some time I simply conceded that wiping down the kitchen cabinets, ceiling and walls was part of brew day clean up and tried to make myself feel better by telling myself “look how clean the kitchen is now!” Didn’t work, still hated that side of brew day.
Well we know that when we are doing our boil we are boiling off anywhere from 3/4 of a gallon to 2 gallons of liquid depending on your batch size and equipment. We also know that evaporated liquid has to go somewhere and cool surfaces is where it ends up. How do we deal with it? Well one could raise the temperature of the room 2-3 degrees above the temperature of the boiling wort to prevent condensation but wait, room temp of 212+ degrees then we die. Scratch that. The solution…ventilate ventilate ventilate!
Being a renter and the last two places I have lived did not have range hoods and one didn’t even have a window that opened so ventilation was a challenge. How much ventilation are we talking? Simply put a lot. Everyone’s ventilation requirements are going to vary so there is no steadfast rule other than err on the side more is better. Most range hoods are inadequate when you are talking the amount of liquid we are boiling off. Some range hoods don’t even vent to the outside of the building instead they suck up the smelly food fumes and blow them out the front of the hood…not sure of the purpose of these at all. Opening a window or door usually isn’t enough either and for it to work you have to have another window or door open to create a draft. Well here in North Dakota where we routinely have winter temps in the -10 to -45 degree range having a bunch of open windows and doors doesn’t make for a comfortable brew day either. I have tried using one of those window fans that has two small fans and it didn’t really do much. Next I tried a bigger box fan in the window with a little better results but still was wiping down the kitchen. I looked at the amount of air these fans are rated to move and compared them to typical range hoods which I knew didn’t work well either and they ranged in the 100-500 CFM capacity. I started looking at other types of fans with higher CFM ratings and they either where huge or very expensive. Plus there was the question of how to mount them and since I rent I want something that is going to be usable in different settings. Well after countless hours searching the web and eBay I found it.
Dayton axial fans. These industrial fans are readily available online and with deep discounts on eBay. They are available in 120V as well as 220V. The model to look for will be the 10″ version and typically are rated at 665 CFM.
I found two of them with the grilles for $45 each shipped. To mount them you can simply get a piece of plywood from a home improvement store that is cut to fit your window that you will be brewing close too. Most Lowes and Home Depots will cut boards to size for you and often have smaller pieces. You will need to cut the circle for the fan to mount over yourself or trade a couple home brews with someone who has a jig saw. If you are lucky enough to have a dedicated brew room then a more permanent mounting can be created. For me, I had a hunk of used 1/2″ thick cutting board that was close enough to the size of my kitchen window so all needed to do was mark and cut the circular holes and screw the fans to the board. To wire the pair of fans you can simply use a power cord salvaged from something and wire them in series or get a switch. You can use a outdoor outlet box to house the switch and wiring and then screw it to the board. I had a small plastic project box left over from another project and I picked up a three step ceiling fan pull switch from Lowes for $5. It allows me to turn on each fan individually or both together.
How does it work? Great, no more wiping down the kitchen. I run both fans at same time for 1330 CFM! Yet even with both fans running it is relatively quiet. I have it in the window above my sink which is close to where I brew. I open the window place the fan in the opening and close the window onto the board to hold it in place. There is a little condensation that forms on the fan grilles while they run, when outside temp are cold, but a quick swipe of a rag every once and awhile through the boil takes care of that. After the boil is done I give the fans a quick wipe down with a rag and done! In the winter the short hour during the boil while the fans are running hasn’t made much of a difference in room temp but has made a big difference in humidity. For around $100 it has been a great investment and a huge savings over anything else that moves that kind of air.
Remember this is for electric brewing. If you want to brew on a propane burner please brew outside for safety sake or consult with a professional regarding required ventilation based on the BTU rating of your gas burner as well as local fire codes. Brewing should be fun, never deadly.