On Aug 26, 7:24 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
"Steve Lusardi" fired this volley :



Lloyd,
These holding plates are filled with a fluid medium and they are
around 18" x 24" x 4" . How much high side and low side tankage
would
be enough in cubic inches to self regulate do you think?
Steve

That's not nearly enough information. You need to know the heat load
at pretty much all operating conditions. You also need to know the
condensor operating conditions. For a job of this nature, I doubt
you'll ever gather enough good info to do it.

Lacking that information, and doing it simply by 'overkill', you'll
have to follow Jon's advice, and keep the compressor running any time
either TEV is open.

You can do that by adding a low-side switch that monitors the
evaporators' exit pressure, and turning on the compressor any time it
goes higher than your desired preset.

LLoyd

The problem is that air conditioning suction pressure needs to be much
higher then freezer suction pressure. As indicated in my post
something like a POA valve is needed so the air conditioning
evaporators operate at a higher pressure then the freezer
evaporators. You still can use thermostatic expansion valves to
control a constant super heat of the refrigerant in each evaporator.

I have not worked this industry since 1977, but my recommendation is
to keep the two systems separate down to dual compressors, and
condensers. Each sized for the application, and operating
temperatures.
ignator