That’s a nice fridge.
One degree either side of setpoint is probably fine as well. Just remember to add some mass to the temperature sensor or let it sit in a glass of water. I wouldn’t recommend immersing it below where the wires enter the probe.
I agree, 1 degree is probably fine, especially when it’s just sitting there being cold. If you’re getting in and out of it a lot and losing the cold air out the fridge door, then 2 degrees is probably better.
I went with a fridge because they’re easier to find and they’re easier to work with. The initial setup can be a chore, but long-term there is very little worry about.
• The fridge will keep beer within serving temperature without any modifications. It’s a fridge.
• Thermal temperature change from opening the door is actually less than if you opened a regular fridge. The kegs–when full–will cool the surrounding air and the temperature of the beer won’t be affected. It’s a fridge, it’s designed to be opened and closed.
• Mounting external faucets is a challenge because the door needs a good amount of modification. Depending on the amount of faucets you want to use, the cost is on-par with buying a faucet post.
• The freezer door on the top won’t get in the way if you use the standard black handles that come with the faucets, and measure before drilling (the height of the faucets is obviously important). Using custom or longer taps handles is a bad idea, not because of the freezer door but because of the angle required to close the faucet. The top of the handle will hit the fridge before the faucet closes completely.
• Fridges are easier (IMHO) to find. I picked up a dent-n-scratch fridge for $200. I use the freezer to store hops and other treats.
I think this is a good thread. Lots of good discussion. I just wanted to throw my $0.02 in from my fridge conversion experiences.
Thanks to all - your remarks have been very useful!!!
bvb :
I have heard that frequently, but it makes no sense to me. Could you explain it further?
You want to control the temperature of the beer. Putting the sensor into something else will only delay the precision of the “control” of it.
The additional mass is just slow it down. It doesn’t effect the setpoint.
I’d argue that you’d want to keep the sensor unchanged and let it sense the ambient temperature of the air in the cooling unit (fridge or freezer).
I understand the goal is to keep the liquid in the cooling unit as close to a certain temperature as possible, but these units are designed to cool the air, not a liquid in a container. If you put a probe in the liquid, it would be harder to control the temperature of the liquid. The cooling unit would not turn on until the liquid exceeded the range set on the thermostat. This would almost certainly mean the ambient air would be much warmer than the liquid. It takes more energy to heat and cool liquid than it does a gas.
These devices work on the concept of keeping the ambient air within a certain range. As long as the gas surrounding the liquid is maintained within a certain temperature, the temperature of the liquid should remain fairly consistent. Unless you’re directly cooling the liquid with another liquid (like glycol) there’s no reason to regulate the cooling based on the temperature of the liquid or any other liquid. It would be inefficient.
It depends on how much water you have in the glass. Yes, if you dunked the probe into a keg of warm beer, the freezer would get as cold as possible before the probe actually got to setpoint. The idea is to stabilize it a little. Controlling air temperature is very difficult. Imagine trying to control the temperature of a hairdryer with a probe in front of it. I know this is stagnant air, but some of the same principles apply.
Also, it doesn’t have to be water. Strap some copper to it. Anything to slow it down a little. Depending on the type of probe, you may not need it anyway.