wrote:

RP wrote:


It won't even cycle on in sub-freezing weather...

It might, with an old refrigerator thermostat in the freezer and
a Thermocube in the fridge that light a 100 W bulb in the fridge

if the freezer rises to 20 F... or the fridge falls to 35 (to avoid

freezing the fridge contents.) Will this hurt the compressor?


http://www.countrysupply.com/products/sku-BEW19.html


That's pretty neat, but it won't help out with the subfreezing condenser
air. Somehow I doubt that a fan cycle control is a viable option


So subfreezing condenser air might hurt the compressor, and controlling
the fan duty cycle to keep the hot coil above freezing might avoid that?

It might, that is, if you could insulate the coil from the ambient
environment during the off cycle. It's doable, but it would be an
engineering nightmare on a stock domestic refrigerator. Refrigerators
take awhile to stabilize running pressures, so starting with a
subfreezing condenser coil might mean that the cycle finishes before the
head control even has a chance to takes control. Head Masters, or
equivalent devices, are installed on commercial refrigeration systems in
order to simulate higher ambients. Without head pressure control, when
the condenser gets too cold the head pressure will drop to such a level
that the evaporator will be starved of refrigerant, even with a TXV in
place, and as a result and superheat will escalate. The evaporator and
compressor are starved of refrigerant. Turtle had it exactly wrong;
flooding back is assured not to happen.

hvacrmedic

A friend of mine is poor and lives in a 50 F house. Her fridge hasn't run
for several months now, so she can't keep frozen foods frozen...

Nick