frig under 55F operation?

paul_79

if i read this right you want to run your refridgerator in a garage/which will be below 55. The problem with running a frige in low ambiant conditions is that you loose capacity. The cond is probably a coil attached to the back of the fridge. in the refrigerant cycle you rely on the temp/pressure difference on the liquid side of the expansion device /txv captube ect. the colder the cond coil gets the less refrigerant goes through the metering device/ and you loose capacity. clear as mud.

jp_2

operation manual says no!

I'm off grid and looking to maximize the frig operation.

I have a 4 cu ft kenmore with the condenser mounted to the back.

I've already moved the condenser away from the frig so I can cover frig in 2 inches of foam.

I planned to pump in cold air(5 watt fan) from outside to cool condenser coil hoping to improve the efficiency.

manual says no to operation under 55F, you once made a comment about freezer/frigs in garages in winter?

so far just pointing the 5 watt fan at the compressor/condensoer seems to help.

I'm severely under powered, I babysit the frig during run periods, I let the frig run 2 cycles in morning and 2 cycles at night. so far a 1/2 gal milk does not go sour before I use it.

thanks

jp_2

going once

???

Unknown

I'm off grid and looking to maximize the frig operation.

Maybe try an old style Paris ice-box,,, that will have no effect on your power grid at all.

Dave

Techman

frige

wHAT DO YOU MEAN BY SEVERLY UNDER POWERED?wHAT TEMP IS THE ROOM THE FRIGE IS IN? wHAT TEMP IS THE AIR BLOWING ON THE COND COIL?Is there an air gap between the cond coil and the new insulation?

Wayne_30

low ambient operation

The main problem with operating a domestic compressor in low ambient temperature operations is the refrigerant migrates back to the compressor body, condenses into liquid, and floats the oil in the compressor body. When the compressor starts, the pistons are pumping oil, liquid refrierant vapors, what ever is available. The reed valves in the compressor will not fair well with solids.
Also the bearings in the compressor are not lubricated with oil, since the liquid refrigerant has replaced the oil.

Commercial compressors operating in low ambient temps have a heater bolted to the compressor body, a way to control refrigerant flow in the off cycle using a liquid line solenoid valve and maybe a fan cycling control.

Minnesota Wayne

Wayne_30

Can you leave the

Can you leave the compressor off when using the fan to bring in cold outside air? Your design has an intake, do you have a way to allow cold air to leave the refrigerator box? Since you are basically pumping air into a sealed box the fan may not be able to move enough cold air to remove the btus from the refrigerator.

I have seen a simular design for walk in coolers to cool product when the outside air temperature is lower than the product. Intake and exhaust fans

Buy a crankcase heater element and strap to the compressor body and keep the compressor body warm

jp_2

that is a current idea

to built an ice house. plenty of saw dust from a local saw mill to use, and lots of cold weather all winter for making snow/ice blocks.

right now I freeze a big dog dish full of water in the little freezer it has.

jp_2

yep

thanks wayne,

my fall/spring plan was to pump cold air directly into the frig when the temp is under 40F, hole in top and bottom of frig. will a probably cause me a little loss in the summer though, just stuff a sock in it I guess.

jp_2

paul,

clear as mud, I'll have to think about that, but I think I understand.

tech: I have only 90W of PV so I rely on sunny days to give me enough power and turn it off at night. I do have 200AH of battery, but if I can't replace what I use in a day the bank nose dives, as in cloud warm weather.

theres a good air gap between the insulation and cond coil. right now the little 5W fan just blows "room floor" air around, little cooler than the room 70ish.