Quantcast

Is your Keezer Killing your Wallet?

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:

I have noticed a lot of people that are building Keezers from chest freezers are building some very nice Boxes, or as some people call them Coffins, around their chest Freezers. These are some very impressive Keezers!

If done correctly this will be no problem, but if the box/coffin is built too close to the exterior walls of modern freezers, it will result in much higher operating costs in the short term, and premature failures of the compressor in the long term.
The compressor needs to get fresh air and many of these Keezer builds do allow for the compressor to get nice airflow.
The problem I am seeing in these box/coffin builds, is that modern freezers today do not have visible exposed condenser coils like in the past.
See an example of exposed condenser coils below:

Manufactures are now embedding the condenser coils in the outside wall of the freezer, just under the thin metal exterior skin.
See where modern freezers place their condenser coils below:

When someone builds the outer box/coffin too close to the freezer they eliminate the freezers means of "cooling" the condenser coils and thus the refrigerant does not cool off properly before cycling back to the compressor.
A Keezer build like this will work in the short term. The compressor will have to run longer and thus your electric bill will be higher then it needs to be. In the long term this will most likely burn out the compressor early, due to the freezers inability to shed the heat in the little air space between the freezer exterior walls and the inside of the box/coffin.
If you intend to build a box/coffin around your freezer design in some cooling fans to circulate the air between the freezer and the box/coffin. I suggest you use some fans that are designed to cool audio/video equipment that are build into high end entertainment centers, like the fan below:

These fans are 115v so no transformer is needed, and if you are controlling your keezers temperature by a separate thermostatic control, you can also plug these fan(s) into the same power source that way the cooling fans only are running when the compressor is cooling the freezer.
Best of luck.
 
Thank you for the article, and for providing pictures that are large enough with high enough quality so you can get the information of the fan.
Question(s), do you have a link for that particular Keezer in your first picture? Is that your keezer? It's awesome!
 
That Keezer belongs to toy maker and can be found here.
https://www.homebrewtalk.com/f51/adverage-keezer-build-price-343573/#post4283408
 
Thanks,
Great insight.... while these keezer builds are fantastic they do most definitely hinder the freezer from operating as it's intended.
 
Thanks for the write up, I'm in the process of dreaming up my build and I was not aware of modern freezers coil location. I will definitely take it into consideration when I finally build mine.
 
I'm in the process of building one of these, and have decided not to add active cooling to the exterior, though I am using an identical fan to circulate air over the shanks on the inside.
My logic is that these freezers are designed to keep the interior at around 0 F, and I'm only asking it too create about half that temperature differential between interior/exterior. I gave it a couple inches between the skin and the cabinet, and I'm just gonna keep tabs on how warm the air in there is getting. If the cabinet seems to be warming up too much I'll create better airflow, but till there's a demonstrated need I ain't going to.
 
@Sharkness
You are giving it a couple inches, which is good and should allow for active cooling if you need it in the future.
Something to think about, would you put a box over your outside AC unit? That is your houses condensing coil. This is in essence what everyone is doing when they are building these box/coffins over their freezers.
I would very much like hearing back on the temperatures that the air reached in the couple inch air gap. Based on measuring the surface temperature of my keezer, when the compressor is running, with an infrared thermometer. I am going to guess the air temperature will be between 100 to 120 degrees. Maybe higher.
 
Completely anecdotal but just for the record here's what I did and how it worked out.
When I built my coffin I put a frame around the corners of the freezer to stand the skin off by about 3/8" (so not a lot but some) and left air gaps of the same size at the back and bottom of the side panels. The skin was thin luan "door skin" so doesn't offer a lot of insulating power either. Prior to the build I had researched where the cooling coils were on my freezer and they were all on the sides with none on the front (corroborated by temperature delta) - had there been coils on the front I'd have wanted to add some ventilation there as well, as it sat I didn't worry about it. The hypothesis is that with the bottom and back gaps there would be sufficient convection to pull the hot air out.
So how well has it worked? Pretty well! The freezer only runs for a few minutes every 2-3 hours when its hot in the house (say over 80) and less when its cool. We also had an electric meter on the house for a while (as part of an energy savings program) and I can definitively say a high wattage light bulbs where a bigger consumer of electricity than the freezer. The unit has been in operation for over 6 years with no evidence of problems.
So I'm going to claim that even mediocre passive airflow should be sufficient. The story could well be different of course had I sealed it all up around the edges :D
Side note: I'll try to remember to stick a thermometer into the gap one of these days and see what that looks like.
 
Just a minor addition, it's not just the compressor that makes heat. To simplify a bit, the refrigerant collects heat, then the condenser acts like a radiator to get rid of the heat the refrigerant collected. Even running for a few minutes you can feel significant heat in the condenser. In a traditional refrigerator you have a fan and directed air flow paths to deal with this heat. Chest freezers don't have that fan or air flow path because they are designed to be exposed so they can radiate heat away from the box. By enclosing the box you are reducing its ability to radiate that heat.
One other thing, not all chest freezers are the same and manufactures change things all the time like features, size, layout etc. So if I'm going to build a really cool keezer (which i plan to do in the future) I'd make sure that when that freezer fails that i have enough wiggle room to replace it easily inside the cabinet w/o having to rebuild the whole thing and/or do everything i could to prolong the life of the unit.
Great article. Thanks for writing it up.
 
Top