How to freeze a CO2 Incubator?

Refrigerated chambers are available from major lab suppiers.

A small refrigerator will provide an "ambient" temperature of 5 degC or less. Just don't try and keep your beer in there too.

Be sure and keep anything with a CO2 purge in a well ventillated area. Don't want to put anyone into permanent sleep.

David A. Smith

Dear David,

thank you for your support, but we can not afford the invest in a new incubator, so we need to adapat the one we have.

Dear esteban_oliveros:

On Nov 13, 1:18 pm, esteban_oliveros wrote: ...

I had given you two suggestions, only one of which you read.

This standard refrigerator:

I have designed and built refrigerated ozone testing chambers, and you will be hard pressed to get anything this inexpensive custom made to your application. Now you might get someone to "collapse" a standard refrigerator around your unit, keeping only the bits necessary to chill your chamber, but it will only "look better"... it won't be improved except in a cosmetic sense.

Go to the used appliance store with a tape measure and try it.

David A. Smith

Dear David,

thanks for your information. Really I read the paragraph related with a refrigerator and a beer, but I did not understand it.

I think that your idea about use a huge and inexpensive refrigerator is very good, but we review all the home refrigerators available in the market (I am in Chile) and no one can contain our incubator inside. ( with 95cm. height 65cm, depth:90 cm, weight: 95 Kg). You saw that is not a good idea the acrylic house around the incubator, Can you give me some instructions to build a freeze chamber where to put the incubator?

I really think that your help is very valuable.

Besta regards, Esteban

Sorry. It was a soft joke.

The cutsheet that was shown in the link you provided had the unit about 65cm in width and depth, with 90 or 95 cm high. You can still modify an existing refrigerator, by cutting open the door, and adding even a second refrigerator cabinet. Might want to add a small fan to exchange air between the chilled cabinet and the "appendage cabinet".

Very poor insulation. May require more cooling than a simple refrigerator compressor / condensor / evaporator can handle. Will condense moisture on humid days, which presents additional heat loading. If you are high in the mountains, not a problem. But if you are near the sea...

Talk to a refrigeration shop local to you. Someone that works with refrigeration ducting should be able to fix you up. Their efforts will cost about as much as refrigerating a home. It probably will look bettter than two married refrigerators. They may also know of a small "walk in" refrigerator, perhaps in a restaurant that is upgrading, or in a recycled components yard somewhere.

And you will still need somplace to keep your beer. (Joke again.)

Good luck,

David A. Smith

Purchase one Frigidaire Chest Freezer volume 19.7 cu ft = 558 liter. Model FCCG201F

Your incubator takes up 20.6 cu ft = 556 liters.

I would not be surprized to find the incubator would not in fact fit.

Until you remove the top lid, and fit a foam insulated collar say 10 cm tall to the freezer, and fix the lid to that.

The best current price on this chest freezer I found with a quick search was $424 (US locations)

Brian Whatcott Altus OK

...

Ahem...those volumes can't both be right. But you get the idea.

Brian W

Bad idea! As I realised, when I looked at the upright incubator you pointed too. Ah well.....

Brian W

How is the "direct heat" generated in this incubator? Is the circulating gas passed through something like a heating coil, or are the heating elements installed in the walls?

In case that a heting coil is installed, I could imagine to replace the heating coil by a kind of "cooling coil". This coil would be the evaporator of a compression refrigeration machine.

In case the heating element is hidden behind the inner wall of the incubator, it could be possible to install the regular evaporator of a refrigerator there instead. Anyhow, you will need to install, seal, check and fill the refrigeration circuit. But: I have no idea just right now, how the refrigeration circuit will withstand the heat treatment (sterilisation?) during the "decontamination cycles" at 95 resp. 145 deg C.

Last but not least: Did you think of using the CO2 itself for cooling? By using CO2 from cylinders with uptake to get liquid CO2 out from the cylinder, you can get dry ice (=3D solid CO2). This dry ice will absorb heat from its surroundings while sublimating to gaseous CO2.

With kind regards,

Mic.