Gear Review: Fun With FLIR One

It's been cold enough to freeze the tail off a brass monkey here, so I was eager to see where we're losing heat in the house. In some places I can actually feel cold air seeping in, but other cold spots are less obvious. A thermal camera would be ideal, but I'm not shelling out $$ for one. But I can borrow one from the local library.

FLIR One for smartphones
(Photo: FLIR)

Arlington County maintains a "library of things" which includes gardening tools, American Girl dolls, board games, a GoPro, and a FLIR camera.

The county lends out several FLIR One cameras to promote energy conservation, but seeing as homebrewing is a temperature-sensitive hobby, it's somewhat useful there as well.

I checked out the Android camera for one week. It only took a few moments to install the FLIR One app on my phone. Once that was done, I was scanning away. I was impressed by its sensitivity. It was able to detect the warm air ducts underneath the floors and even my footprints on the cold floor. After I swept the inside and outside of the house looking for cold spots, I took it to the brew room.

Homebrew in Infrared

The FLIR confirmed what I already knew about the brew room: It's modestly insulated with a few minor cold spots where the exterior wall is breached. This time of year, it stays at around 60°F with no forced-air circulation. The poured-concrete floor acts like a giant heat sink, so I can ferment at ale temperatures for 8-9 months out of the year without any artificial cooling.

ESB in infrared

So what does beer look like to FLIR? I trained the camera on a batch of ESB in the Spiedel. The FLIR adjusts its sensitivity automatically depending on the levels of heat it registers, so even slight differences in temperature appear stark. The Spiedel looks like a warm blob, and you can even make out the level of the beer. It's practically incandescent in infrared.

I also have a small batch of lager fermenting in my new fermentation chamber (blog post coming soon!) and I tried to take a picture of that as well. While I could see the bucket visually, it was practically invisible in infrared. The inside of the chamber and the beer were both at 55°F. The only thing I could make out was the wire for the Inkbird's temperature probe. There was basically nothing to see, so I didn't even bother to snap a picture. That's actually a good thing.

Blanketed fermenter

I also took a picture of the Spiedel with its thermal blanket over it, which is just the thin Reflectix-like bag that my Blue Apron shipments come in. It's not a great insulator, but anything to slow down the cooling is a plus. It seems to be working. You can see the warm beer peeking out below the bottom edge, but it's cooler everywhere else. Incidentally, that warm spot in the middle is me: the blanket is reflecting back my IR signature.

I have a FermWrap hooked up to my other Inkbird and the temperature set to 65°F with a 1°F heat differential (meaning it will kick on at 64°F). With the blanket, it takes several hours for the batch to cool down to 64°F, so it's doing its job.

Verdict: Useful to rent or borrow, but don't buy

The FLIR One is a neat little tool. It's not worth buying for most homebrewers, except for those that have $200 burning a hole in their pockets. But if you can borrow or rent one, it will be very useful to check the efficiency of a keezer build or fermentation chamber.