Can a home freezer maintain -23C/-10F

[dude]

Crystal growth on ice cream can be slowed down by lowering the temperature.

I glanced at a thermometer in a supermarket ice cream display case and it read -10F, which is about -23C.

The refrigerant on that machine was R-502

Could a home freezer based on R134a reliably maintian -10F?

[Latte]

Hello Dude,
There is no reason why a home freezer couldn't hold -23c
Providing the insulation is good. The only thing you have to remember is that because of it's size each time you open the door the temp will rise quite a bit. A lot of freezers now use R134 and works OK.

Regards

Raymond

[shogun7]

You would have to run in a vacuum to get down that low and it does. Too bad we can't use R 13B1 we would be in positive pressure territory, however, it's flamable, but it does replace R- 12

[Mark]

In supermarket ice cream cases (fhgd) can display the ratio at which the user selects.The configuration of the case software varies.A basic home freezer usually only measures the temperature at one point,and cycles the compressor as required.

regards mark

[dude]

I have a digital thermometer embedded inside a bag full of ice cubes placed in middle of the chest freezer surrounded by all the other food and it is keeping -10F/-23C as of now, but my question is as the evaporator runs below atmospheric, does that present a reliability issues?

Could the freezer hold -23C if the ambient tempreature goes up to 32°C during the sumemr?

[shogun7]

Dude
It should, but it will run longer, it't really a function of temperature difference between the the ambient temp and box temp. in a word "costs" will increase. Oh and what time is your sumemr? Just kidding!

docendo discimus

[neil sailes]

Dude
We refurbish all sorts of freezers for nestle, and one type of unit they use for backroom storage is a norfrost standard r134a chest freezer . They must work alright for the job because we don't see too many of them back in the workshop.

Neil.

[Prof Sporlan]

Too bad we can't use R 13B1 we would be in positive pressure territory, however, it's flamable, but it does replace R- 12

Mmmmm..., shogun7, you must be thinking of another refrigerant. R-13B1 is a halon, and as such, used as a fire extinguisher. It was also used occasionally as a refrigerant in single stage refrigeration units operating in the area of –60°F evaporator. But like R-12, it is a CFC, and now history.

[superheat]

Only problem is pressure ratio and its effect on compresser capacity.

Lets say the freezer is open for a while and the temp rises to say 15F. The compresser will pump ***** through the system. As the suction pressure drops the pressure ratio will rise. It will take just as long for the freezer to get to say -5F no matter where the thermostat is set. If the t'stat is set for -5F, the compressor will stop now. If it is set at -15F, the compressor will still run. Eventually the compresser will continue to run because heat is leaking in faster than the compresser can pump it out. Kind of like being on a leaky boat with a bilge pump that is not working right.
You could add insulation to the side of the box to help get a little lower temp.