On Jan 28, 12:54*pm, wrote:
On Thu, 28 Jan 2010 10:39:00 -0500, blueman wrote:
I have always wondered about this one...
Refrigerators are one of the top energy consumers in homes.
In Northern climates, the outside temperature is colder than indoor
temperature at least 6 months of the year.

Why aren't they designed with "heat" exchangers to benefit from cool if
not frigid external air?

Even in warm climates (or summers) why isn't the same principle used to
vent the warm air from the compressor & coils outside rather than
loading the AC?

Presumably this could all be done by putting the evaporator coils
outside which would in turn decrease (or eliminate if cold enough) the
draw on the compressor during winter months.

Of course, installation might be a little more expensive, but with all
the focus on green-this and green-that why isn't this being done?

Cost, complexity and reliability.- Hide quoted text -

- Show quoted text -

Yes: Cool idea. Maybe.If fridges could draw in (and exchange) cool
outside air instead of using electrcity. But some refrigeration and
air controls would still be needed. Not sure the saving would be
significant if at all?

And with existing conventional electric fridges! Within the house all
the electricity used by the fridge ends up as heat. In our cool
Newfoundland climate some heating is needed most months of the year.

So in a house that is electrically heated (as most are these days) the
fridge heat merely replaces that from the electric heaters or other
means used for heating the home.

A fridge is basically an electric motor driving a pump that takes heat
out of the inside of the fridge and pumps it into those coils on the
back of the fridge. It's a heat pump. The motor also wastes some of
it's input (nothing is 100% efficient); it gets a little warm and that
heat stays within the house.

By putting say the coils outside might mean the fridge would run less,
thus saving electricity. But outside during a cold winter would
basically waste that heat outdoors. Warmth that originally leaked into
the fridge from the house and/or every time its door was opened, being
pumped outdoors. Same thing as running an air conditioner except in
this case it's only the fridge interior that is being cooled not a
room!

And since a 300 watt fridge can pump something say of the order of
1000 watts of heat; better IMO in cold weather to keep all the energy
used by the whole system within the house.

In a very hot climate the idea 'might' have some merit, if the cost/
complexity was reasonable? But pumping fridge heat outside into say 30
or 40 Celsius (90 to 110 F) atmosphere (Does it EVER get that warm
here?) outside might mean the fridge would have to run longer; thus
using more electrcity!

Overall the best course might be to have bulk of ones house
underground and utilize any/all sources of energy (mainly electricity
these days) entering it as a source of warmth. One of the bigger
'wasters' at moment being clothes dryers which chuck their warm damp
air outside. But anywhere else in the home that moisture can cause
mould/rot. That's why ventilation (especially attics) is so important.

Have seen a few homes here where there was a cold room built out fom
the basement, say under the front steps that stayed something close to
the temperature of a typical fridge. Useful for beer, potatos etc.