Chest freezer can operate as fridge?
October 12, 2005 1:26 PM Subscribe
Can I operate a chest freezer as a refrigerator?
I need to keep some long sample tubes cool. A large chest freezer would be the right size, but I don't want to freeze the samples (or risk freezing them). I don't currently have such a freezer. Searching turns up special beverage chest fridges from the retail and restaurant industry for 2000 bucks, but no info on whether a household freezer will run as a fridge. Can I just turn the thermostat way up on a freezer and have it run cool but not frozen?
I need to keep some long sample tubes cool. A large chest freezer would be the right size, but I don't want to freeze the samples (or risk freezing them). I don't currently have such a freezer. Searching turns up special beverage chest fridges from the retail and restaurant industry for 2000 bucks, but no info on whether a household freezer will run as a fridge. Can I just turn the thermostat way up on a freezer and have it run cool but not frozen?
How long? If you jury rig a thermostat it'll work, sort of, but it won't be very effecient and you risk frost build ups. You'd be much better off buying an all fridge. As a bonus they take up a lot less floor space.
posted by Mitheral at 2:00 PM on October 12, 2005
posted by Mitheral at 2:00 PM on October 12, 2005
Response by poster: Mitheral -- I should have mentioned, the samples need to be stored horizontally (to prevent internal slumpage of contained sediments), and even the all-fridge is not "deep" enough to prevent slicing the sample tubes up too much. A cold room would be ideal but I don't have one of those, either! I need to keep them in good condition and cool for about three years.
jclovebrew: that looks ideal, but what about Mitheral's comment re: frost buildup? Any thoughts on that? I won't be paying for the electricity so that part isn't an issue (except in a global sense).
posted by Rumple at 2:33 PM on October 12, 2005
jclovebrew: that looks ideal, but what about Mitheral's comment re: frost buildup? Any thoughts on that? I won't be paying for the electricity so that part isn't an issue (except in a global sense).
posted by Rumple at 2:33 PM on October 12, 2005
Never heard of any issues with frost buildup. Especially since the temperature will be above freezing. From everything I've heard, it's actually a very efficient setup. The PDF linked above supports this.
posted by jclovebrew at 2:50 PM on October 12, 2005
posted by jclovebrew at 2:50 PM on October 12, 2005
The frost buildup issue is simply resulting from the fact that most modern refridgerators have fans to make them "frostless". If you wanted to take queues from that, you could rig a low-voltage fan and install it in the freezer and have it turned on with the compressor when the temp raises. This will provide air circulation, and will subsequently reduce frost buildup.
posted by quadrinary at 2:53 PM on October 12, 2005
posted by quadrinary at 2:53 PM on October 12, 2005
You shouldn't have frost buildup if the freezer is kept above freezing.
posted by 6550 at 3:53 PM on October 12, 2005
posted by 6550 at 3:53 PM on October 12, 2005
Best answer: Homebrewers do it all the time to chill their kegs and control fermentation temperatures.
Yup, that's me. Here's the description of my kegerator project, with prices of everything.
posted by gurple at 4:21 PM on October 12, 2005 [1 favorite]
Yup, that's me. Here's the description of my kegerator project, with prices of everything.
posted by gurple at 4:21 PM on October 12, 2005 [1 favorite]
(for quick reference, $200 for the chest freezer, new, and $90 for the thermostat)
posted by gurple at 4:22 PM on October 12, 2005
posted by gurple at 4:22 PM on October 12, 2005
Best answer: Rumple writes "I should have mentioned, the samples need to be stored horizontally (to prevent internal slumpage of contained sediments),"
Ah, that's a problem. I was thinking you could stand the tube on end.
Rumple writes "Mitheral's comment re: frost buildup? Any thoughts on that? "
Your standard chest type has steel lines attached to the metal liner with clips. The refrigeration cycle is designed to freeze things so the coils will drop below freezing every time the compressor runs even if the interior is kept above freezing. This will cause frost to form on the steel lines that melts when the add-on thermostat cuts the power because the interior is above freezing. Water+steel = rust = eventual failure. Modern freezers using foamed insulation are more resistant to this than old fibreglass insulated units but they will eventually fail. Having said all that you would probably get years of use before the refrigerant leaks out. You may end up with a ball of ice in one specific location inside if you have a lot of moisture inside and you are opening and closing the door a lot or are cooling a lot of mass down.
Now you might be thinking why would they use something as brain dead as steel in this application? When a freezer is used as designed the frost never gets a chance to melt and therefor the steel doesn't rust. This is why you shouldn't unplug a chest freezer to defrost it; instead just empty it and use a plastic egg flipper or spatula to scrape the ice off the side walls. Also there aren't any coils on the bottom so you should never place unfrozen food directly on the bottom.
posted by Mitheral at 5:24 PM on October 12, 2005
Ah, that's a problem. I was thinking you could stand the tube on end.
Rumple writes "Mitheral's comment re: frost buildup? Any thoughts on that? "
Your standard chest type has steel lines attached to the metal liner with clips. The refrigeration cycle is designed to freeze things so the coils will drop below freezing every time the compressor runs even if the interior is kept above freezing. This will cause frost to form on the steel lines that melts when the add-on thermostat cuts the power because the interior is above freezing. Water+steel = rust = eventual failure. Modern freezers using foamed insulation are more resistant to this than old fibreglass insulated units but they will eventually fail. Having said all that you would probably get years of use before the refrigerant leaks out. You may end up with a ball of ice in one specific location inside if you have a lot of moisture inside and you are opening and closing the door a lot or are cooling a lot of mass down.
Now you might be thinking why would they use something as brain dead as steel in this application? When a freezer is used as designed the frost never gets a chance to melt and therefor the steel doesn't rust. This is why you shouldn't unplug a chest freezer to defrost it; instead just empty it and use a plastic egg flipper or spatula to scrape the ice off the side walls. Also there aren't any coils on the bottom so you should never place unfrozen food directly on the bottom.
posted by Mitheral at 5:24 PM on October 12, 2005
Response by poster: jclovebrew and Ritchie -- thank you very much. That solution looks excellent, and the PDF file is very useful and encouraging.
Mitheral, thank you for your answer and for your trouble in finding those links, and explaining that the frosting issue is not inside the food compartment, which puzzled me.
These answers are just great and will probably save me 1200$ or so versus the commercial units. And next time I will know to google for "kegerator".
posted by Rumple at 5:36 PM on October 12, 2005
Mitheral, thank you for your answer and for your trouble in finding those links, and explaining that the frosting issue is not inside the food compartment, which puzzled me.
These answers are just great and will probably save me 1200$ or so versus the commercial units. And next time I will know to google for "kegerator".
posted by Rumple at 5:36 PM on October 12, 2005
This thread is closed to new comments.
Forget the built in thermostat though. You will need an external temperature regulator/thermostat, that will turn the freezer on and off. Here is an example of what I'm talking about.
Good luck!
posted by jclovebrew at 1:34 PM on October 12, 2005