refrigeration engineer

Probably, you'll need install a (Two Temp Valve) on the warmest evaporator on the suction side to compressor. It called also (Constant Press. Valve). " Two general types of two temperature valves are:

1) Pressure operated.

a) Metering.

b) Snap-Action.

2) Temperature operated.

a) Sensing bulb and bellows.

b) Thermostat and solenoid.

Some of these valves have a gauge opening. This allows the technician to check and adjust the warmer evarorator's pressure. Have your correct (TXV) Thermostatic Expansion Valves also review with a properly 'Superheat' differential of about 10 to 12 (deg. avg.) operation and you'll be in good shape to tackle it down.

But your parts suppliers will give you much more feedback specifics data on how to do it rigth anyhow, I'll Bet. All set Buddy hang in there and don't rush into nothing.

Lock and Tag for Safety Always,

MC

I have a respectable amount of experience with refrigeration systems, but am not a refrigeration mechanic, but I learned a lot of what I know about refrigeration systems from knowledgable refregeration mechanics and engineers.

Can you explain why it is unsatisfactory to simply install an on-off valve in the refrigerant supply to each evaporator that is controlled by a thermostat on its respective portion of the freezer? Since only one compressor is being used, it would seem the end result is the same either way.

Is the surge receiver any more necessary because of two evaporators, or just a good insurance policy any time?

The superheat on the warmer side would presumably be set higher than the cold side, but I'm not sure if this is necessary. The evaporator coil would just run colder than necessary if the superheat were set the same.

Actually I like the simplicity of a fan as suggested by Vicini. It could be switched on by a simple thermostat as needed. If the fan blowing from cold to hot is located at the top of the cold section and the return at the bottom, a desirable air circulation pattern would be set up in both sections.

put all the refrigeration evaorato coils in the -20 side. Use a fan to move cold air to warmer side as needed, that how a home refrigerator works.

OHhhh Brotherrrr! Well one more thing to hook those puppys up will be nice to have a nice capacity receiver fixture to avoid any sudden liquid refrigerant sludge to compressor just in case my friend.

Hanging in There,

MC

If the multiple systems have been set up correctly it should not happen e.g. what happens when one of the systems shuts down under normal operation..........the system is okay.

OR

Am I misunderstanding the question............will the volume of the entire system change.........if it doesn't you shouldn't have a problem...........I'm in a hurry, going on holiday for three weeks in a couple of hours.

.......to avoid any sudden liquid refrigerant sludge to compressor

Your T/X valve should control things............are there accumulators fitted to both systems.......not that they should be required..............the liquid receiver should be able to manage the total refrigerant charge during alterations. I say this because during maintenance periods the refrigerant from both systems would be pumped down to the liquid receiver.

Yeaaahh you got it rigth Buddy's the --Accumulator-- it's crucial and also I will install probably for those puppy's couple of check valves as an insure to refrigerant flow, Haaheehaaii..

Hey Buddy enjoy your time out and relax now we'll take care as well, No Problemooohh!

Bring couples of pictures from there, that's the catch. Always some catch some how. Deaammnn...

Hennessy Time,

MC

I have some experience in refrigeration field as a mechanical engineer and HVAC/R contractor.

Do you mean you want to divide the freezer room to be two sections, one -20c and the other -1c?

If so, you have to upgrade the refrigeration system, you may use the same compressor and one of the original evaporators for the freezer section. And you have to replace the other evaporator (it will be smaller size than freezer's evaporator) to match the heat load from the cold room section. Both rooms temperature should controlled by thermostats and solenoid valves individually. And make sure the system has receiver. Otherwise the compressor will get damaged.

good luck..

I know this is 4 years too late.

You could use existing gear quite hapilly,

with T/stats and solenoids to control each room.

Do fit an evaporator pressure regulator to the coolroom evap - to maintain a minimum evaporator pressure - this will prevent over shooting of the desired temp but also minimise chance of evap icing up.

Compressor unit should have the suction accumulator kept in the suction line -you only need one as you are only protecting one compressor.

I do recommend use of digital controllers to manage temp and defrost for the individual rooms.