Newsgroups: misc.consumers.house,sci.energy,sci.environment
From: jgd@dixie.com (John De Armond)
Subject: Re: Refrigerator Coils outside
Message-ID: <_pvxj_+@dixie.com>
Date: Tue, 13 Jul 93 10:18:00 GMT

maa@sisd.kodak.com (Mark Armstrong soft) writes:


>With all the talk about "$30M refrigerator design", I was
>wonder if anybody makes a refrigerator with the coils and
>compressor seperate. I plan to place my frig next to a
>large pantry which is on the north side of my house.
>I want to place the compressor in the pantry with the
>coils outside to take anvantage of the cold temps in the
>winter (I will build a false wall to hide the coils, don't
>think the wife wants to see coils as she drives up to the house).

I don't know if anyone makes one but I made one for myself over 20 years
ago when I was an efficiency fanatic.  I simply yanked the condensing
package out of the 'frig and put it in my unconditioned basement.
For a variety of reasons it is not a good idea to expose a standard
condensing package to temperature extremes.  Placing the condensing
coil in a crawl space or basement is better than the raw outdoors.
The only real precaution you need to watch for is to keep all the lines
generally sloping toward the condensing package.  Dips or loops can
form oil traps that will gurgle and which can affect efficiency or even
trap out enough oil to starve the compressor.  Also, go up on the line
sizes at least one size for reasonable (20 ft or so) length runs.


>Also, can 1 compressor run the freezer and frig? All the components
>will be locate next to each other.

If you're asking can you run a separate freezer and refrigerator off
the same condenser package, the answer is yes.  How efficient it is
depends on how clever you want to get.  For example, you could route
the suction line from the freezer through to the refrigerator.  Though
dry, the refrigerant is still cold and can contribute to cooling the
hotter refrigerator.  Or you can use the freezer suction to cool
the liquid going into either the freezer or refrig.

In any event, the condensing package must be designed for the lower
temperature.  The individual box thermostats control solenoid
valves to admit refrigerant to the box.  Or backpressure regulators
can be installed to keep the evaporator vapor pressure at the right
level.  Or a combination of the two.  The condensing package is typically
controlled on suction pressure, turning off at a low pressure setpoint and
turning on at a higher one.  It is also common to incorporate a suction
resevoir in order to stretch the cycle time.  As the condensing
package will spend a significant amount of its time underloaded,
one of the phase angle power factor controllers (Home depot is now carrying
one for about $40) should aid efficiency.

Refrigeration hacking is a lot of fun and the equipment isn't too expensive.
Give it a shot.

John

--
John De Armond, WD4OQC               |    (Pardon the inconvenience while we
Performance Engineering Magazine(TM) |    remodel this .signature)
Marietta, Ga                         |
jgd@dixie.com                        |