Update on ref in garage.

[Geo-TH,In]

Well my garage is up to 45 degree, ref is at 32 and freezer temps are at 16. Guess this proves the newer 134a refrigs don't like working in a cold unheated garage.

The only changes I'll make is moving my ice cream to the ref in the kitchen in the winter.
George

 

[Anonymous-0]

Household refrigeration appliances need approximately 50 deg. plus to operate efficiently.

Reason......below 50 deg. the condensor becomes too cold to keep the condensing pressure high enough to deliver the required refrigerant to reach the evaporator located inside the appliance.

Actually 70 deg. is the opptimum ambient temp for the appliance to operate properly.

The compressors usually will operate continusously in order to satisfy the thermostat.

HTH John,PA Ref. Engineer

 

[Geo-TH,In]

Is there a max temp for 134a refrigs to work best at? Times garage gets warm in summer.

 

[IH2444]

(quoted from post at 14:58:33 01/11/14) Is there a max temp for 134a refrigs to work best at? Times garage gets warm in summer.

I thought that the main problem was that if it got say20 deg around the fridge the fridge tem would drop below the thermostat cut on temp and the freezer would warm up.

Is this wrong?

 

[Geo-TH,In]

IH2444,
You are right. It's below 30 degrees. When the ref section gets below 30, thermostat won't turn compressor on and ice cream melts at 30.
George

 

[Geo-TH,In]

Garage is 45. Went shopping, put warm soda in ref, ice cream in freezer. Freezer is now -20. So putting warm things in ref will make compressor run longer making freezer colder.

 

[Hobo,NC]

You have a Engineer on board maybe he can help... I would think as long as liquid turned to gas it would freeze colder than ell... Is it possible the refrigerant stays in a liquid state... Its a heat exchanger so were do you draw the line if there's no heat to exchange...

 

[David G]

I do not think it is a refrigerant issue, just that there is one compressor for both sections, it has to run to work.

 

[missouri massey man]

(quoted from post at 08:04:50 01/12/14) I do not think it is a refrigerant issue, just that there is one compressor for both sections, it has to run to work.

.....uuuuhhhhhmmmm....just like a wood furnace "heats" your house quite well in the summertime without a fire, so too does your refrigerator "cool" its load in the wintertime quite well when subjected to such low ambient temperatures (within reason). The rate of heat gain on the inside of the box is directly connected to the box's surrounding temp. In other words, it ain't gonna gain interior temp very quickly (with an unchanging load) due to the relatively low difference in temperature between the inside and outside of the box.

Adding warm product and adding it quite frequently will increase the temp inside the box closing the thermostat and causing a run cycle but as soon as the thermostat satisfies, it will take a greater length of time before another cycle is initiated due to the low temp differential.

As stated before the ideal ambient is 70F to 72F and the compressor will run for a much longer cycle to attain the -4 (or whatever) freezer temp to satisfy the t-stat. Minus 4 setpoint to 72 degrees ambient equal a 76 degree td (temp differential) resulting in a normal "on cycle" whereas -4 setpoint to 20 degree ambient is a 24 degree td results in a less than normal "on cycle".

You will be dis-satisfied with the storage of lettuces and fruits in the low ambient application though, but unless it is subjected to an extremely loooooonnnnnnngggggg time frame of this severely low temp, you should see no appreciable detriment (melted ice cream) to at least a fairly adequate refrigerator. Key disclaimer: loooooonnnngggg time frame and ice cream can soften, but nothing should thaw....

Condensing temperature does in fact come into play as commercial refrigeration typically has what is called a "low ambient kit" installed which essentially stops condensor fan operation to force higher condensor pressure (and consequently higher condensing temperature and starts it again to maintain operating pressures within that determined range.

A more refined way to sustain this condensing temperature is with a solid state device whose sensor clamps onto a return bend on the condensor coil or possibly on the liquid line and varies a signal from 0 to 100% to effect the rpms of the condensor fan motor to limit the air movement across the condensor coil, causing the pressures to be maintained within that determined range.

Volumns can and have been written on this subject and in no way is this a complete explanation....cliff notes and rudimentary at best.

 

[Chris Jones]

You might consider rigging an incandescent light bulb in the fridge (on constantly) to warm it up a bit making the fridge need to run the compressor every so often to compensate for the bulbs heat--when it's running the freezer is getting cooled too. It'd take a bit of testing to see what wattage bulb it would take.

 

[Anonymous-0]

If the ambient temperature is too LOW for the design of the condensor coil, The liquid refrigerant will not have enough pressure to send the required amount of ref. to the evaporator (freezer) section through the expansion device, (capillary) tube.

The appliance will show too low of a suction pressure, sorta like being low in refrigerant. Even though the amount of refrigerant is normal for the factory.

So, if the appliance is moved to a warmer ambient, the pressures will be normal. Lots of times a service personnel will claim the unit is low in refrigerant, and, after the ambient temps. warm-up.....the unit is overcharged as evident with frost covering the suction line and perhaps the compressor shell.

We use fan controls and other devices to keep the condensing pressures within certain ranges for low ambient conditions, on commercial equipment.

John

 

[Hobo,NC]

(quoted from post at 01:37:43 01/14/14) If the ambient temperature is too LOW for the design of the condensor coil, The liquid refrigerant will not have enough pressure to send the required amount of ref. to the evaporator (freezer) section through the expansion device, (capillary) tube.

The appliance will show too low of a suction pressure, sorta like being low in refrigerant. Even though the amount of refrigerant is normal for the factory.

So, if the appliance is moved to a warmer ambient, the pressures will be normal. Lots of times a service personnel will claim the unit is low in refrigerant, and, after the ambient temps. warm-up.....the unit is overcharged as evident with frost covering the suction line and perhaps the compressor shell.

We use fan controls and other devices to keep the condensing pressures within certain ranges for low ambient conditions, on commercial equipment.

John

Both reply's about adding condenser fan controls makes the most sense to me... Its good info to know,,, in my world (automotive) I don't have to deal with issues in real cold weather... I learned sum'n from those tip's I hope I never need'em :wink: