lagering/fermentation fridge performance update

Hi,

Some time ago I mentioned my fermentation/lagering set-up with a converted side-by-side fridge: https://www.homebrewtalk.com/showpost.php?p=59730&postcount=14

Time for a hot weather performance update. The last 2 days have been on the warmer side here in North Carolina and the temp in the garage hit 30*C (~85*C) and remained there for quite some time. At this ambient temp, my set-up is only able to maintain a temperature of about 13*C (~56F) inside the fridge part. At this point the fan is constantly running. The freezer part is still OK, but due to the continuous running of the fan, I'm afraid that I get serious temperature gradients. Even to the point that I can't put a keg to close to the condenser of the freezer because I'm afraid it will freeze the beer inside while the rest of the freezer is at 3-5*C (38-42F). Just because the compressor has to run for such a long time.

This problem could be solved by installing a fan inside the freezer that will constantly run and circulate the air and putting a foam pad between the keg and the condenser.

But right now, I'm not worried about improving this set-up. We plan to move back to the Boston area in June and there we *will* have a house with basement and I don't have to worry about 80-90F ambient temps. If I wouldn't be moving I would seriously consider making a fermentation/lagering set-up with some plywood, lots of Styrofoam and a window AC that I have lying around.

I just wanted to give an update on the problems that my set-up has, in case someone is going for something similar.

Kai

If the compressor has to run full time to maintain 3-5*C in the freezer section, there's something seriously wrong somewhere.

That's what I was thinking. Is it sealing properly?

Mikey said:

If the compressor has to run full time to maintain 3-5*C in the freezer section, there's something seriously wrong somewhere.

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Well I don't think it has to run full time. I just has to run much more than before and that causes the temp gradient.

Kai

I still don't quite capeesh. The freezer section normally operates at around 0*F, and the fridge side at around 35*F. Why would running both sides at higher temps cause the compressor to run longer?

Mikey said:

I still don't quite capeesh. The freezer section normally operates at around 0*F, and the fridge side at around 35*F. Why would running both sides at higher temps cause the compressor to run longer?

Click to expand...

Due to the increased ambient temp, more heat energy is coming into the fridge through the insulation. The greater the temp difference between 2 adjacent spaces is, the more energy it takes to maintain this difference.

Kai

Kai,

I just purchased a used side by side after seeing your setup. I planned on using the fridge part to ferment ales and the freezer to put kegs and taps. I live in Houston and it gets really hot here you think I will have any problems maintaining 62F on the fridge side by using a external stat and putting it in the freezer side?

fa1321tx said:

Kai,

I just purchased a used side by side after seeing your setup. I planned on using the frige part to ferment ales and the freezer to put kegs and taps. I live in Houston and it gets really hot here you think I will have any problems maintaning 62F on the frige side by using a external stat and putting it in the freezer side?

Click to expand...

As long as it's in your house...nope. I'd think in an enclosed garage the fridge would run a LOT. Especially during late July/August when it's 100+ outside. I'm in the same boat as you because of being local to the hot arsed Houston weather. My Kingdom for a cool Cellar!!!!!

I have another fridge at a neighbors I need to go pick up for my lagering/kegerator. Already have an industrial Coke machine for lagering which jacked my electric bill $30 last month with only a week and a half of usage. Wife's going to be REAL happy when we start our 20 gallons at a time brews and the fridges run non-stop. Going to keep an eye on temps in the garage and am considering putting a vent fan in the ceiling to vent hot air from garage into attic, which will vent outside house. Hell...worst case...I insulate garage door, and install a buttload of weatherstripping around the door, and get central a/c for the garage.

Jester4176 said:

As long as it's in your house...nope. I'd think in an enclosed garage the fridge would run a LOT. Especially during late July/August when it's 100+ outside. I'm in the same boat as you because of being local to the hot arsed Houston weather.

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It does get pretty F***ing hot in my garage but I would hope to maintain at least 55F in the freezer then hopefully the fridge part will be around 65F. The fridge I got is 26 cu ft so maybe it has a big enough compressor to do the job. Also this fridge looks to have been really taken care of all the seals are in good shape. I just ordered the Johnson Controls A419 digital temp controller for my set up it is supposed to keep you within 1F of your set temp. I guess time will tell!

Kaiser said:

Due to the increased ambient temp, more heat energy is coming into the fridge through the insulation. The greater the temp difference between 2 adjacent spaces is, the more energy it takes to maintain this difference.

Kai

Click to expand...

Which goes back to my original point- if your compressor is working that hard, there's something wrong. Even if it's 30*C ambient, your fridge shouldn't be struggling especially with inside temps set so high. Not arguing with you, just expressing an opinion.

Mikey said:

Which goes back to my original point- if your compressor is working that hard, there's something wrong. Even if it's 30*C ambient, your fridge shouldn't be struggling especially with inside temps set so high. Not arguing with you, just expressing an opinion.

Click to expand...

Well, I think the freezer part is ok and the compressor is very well able to keep the tremp there. I may have seen things wrong there. But it still struggles to keep the fridge part around 12-13C (54-56F). This is just a limitation of the airflow through the fan.

Kai

I got some questions regarding the shelving that I added to the freezer part of this fridge. Here are pictures for this:



I took 4 1/2x1 inch pieces of wood and notched them 1/4 in deep such that I can slide in pieces of plywood. Then I screwed the wooden posts to the sides of the freezer compartment using the holes that already existed from the original shelving in this freezer. The pieces of plywood can then be installed to hold bottles for lagering. Currently I have only the upper shelf installed. This is where I store my yeast samples.



The lower part hold 2 corny kegs for lagering. I wrapped one of the kegs in some foam padding in order to reduce temperature fluctuations. But I'm not sure how useful this actually is.



The keg in front needs to be lower than the keg in the back so it doesn't interfere with the ice dispenser in the door of freezer part. If it would be higher, the door won't close.

Kai