Designing a cold box

 

It seems a waste of energy to run a refrigerator in a heated house during
the winter months.  Why not run small ducts into the coldbox from the
outside, with a thermostatically-controlled damper valve to control the
temperature?  That could greatly reduce the energy consumption of the
refrigerator when outside temperatures are low.

I can think of an electric servo system controlled by electric thermostats,
but does anyone know a simpler way?  Are there gas cylinder servos or
bimetallic springs that could maintain a steady temperature inside?

It seems like it could work with an existing refrigerator or a cold-storage
cabinet in the house.  Are there any such dampers on the market?

 

my fridge has such a device between the fridge and freezer to control
the amount of cold air entering the fridge...

It is Robert Shaw and has a capilary tube and a fluid in a copper
expansion chamber that expands and operates a push rod which actuates a
small door...

 

my fridge has such a device between the fridge and freezer to control
the amount of cold air entering the fridge...

It is Robert Shaw and has a capilary tube and a fluid in a copper
expansion chamber that expands and operates a push rod which actuates a
small door...

 

my fridge has such a device between the fridge and freezer to control
the amount of cold air entering the fridge...

It is Robert Shaw and has a capilary tube and a fluid in a copper
expansion chamber that expands and operates a push rod which actuates a
small door...

 



I think there was a similar thread recently asking whether a fridge
uses less power when in the cold (eg a cold basement), rather than in
a warm part of the house.
AFAIK the answer has to be yes - and some efficient fridges such as
the Elcold publish different power usage figures depending on the
ambient temperature of the surrounding air.
Just how LOW that ambient temperature can go is a matter of debate,
and our new fridge gives a low temperature of (ambient air) operation
that is well above freezing. I suspect this is mostly to do with the
viscosity of the oils in the compressor - hope someone can shed light
here.

Personally, I would make a "cold enclosure" - vented to the underneath
of the house in our case, with maybe a small computer fan to circulate
cold air from outside (this could be easily controlled by a thermostat
if necessary). In the enclosure would be a standard fridge - hopefully
then using much less power.
I think controlling dampers would be much more difficult.

Eric