Multiple Evaporators

[rcz]

I've been doing heating and air conditioning for 15 yrs and have got a cooler to put in now I've installed several single coil coolers and this one has three coils and one condensor and was wondering about the piping of the three....and if i need to install an EPR on each evaporator

[angryk]

Are all the evap coils in the same cooler, or are they each cooling a different, seperate cooler?

[rcz]

They are in the same cooler . the M# coils are AA36-145 hooking them up to a D1h5H22 ..R-22 medium temp

[Dan]

You do not need an EPR anywhere, unless there is something you are not telling us. I am assuming that this is beverage type duty, with a thermostat controlling either or both the compressor motor contactor and a liquid line solenoid.

[rcz]

Do I just tee them or do i need down says the pipe to each unit .

[Dan]

Just tee them. You could size each branch for the capacity each individual coil, but I don't see the necessity in this case.

Also, just for a way to shift your thinking from one who connects pipe to one who understands why pipe sizing can become important, think this way:

You are not downsizing pipe. You are enlarging the size of pipe to accommodate the combined loads after they join together to permit more flow.

[rcz]

Thank's Dan that is what I was think but it has been awhile since I've been in school.Thank Again

[Kathleen]

Hi rcz,

Pay a great attention to your pipe size, depending if you have one liquid solenoide coil or three liquid solenoid. Does the compressor can be unloaded.

With R-22 refrigerant you need to make sure your oil is well return to your compressor, therefore the line size is important. You should make sure in full capacity not to be faster than 4000fpm and in small capacity not lower than 900fpm.


if i need to install an EPR on each evaporator

An epr is there to maintain a different temperature on the evaporator than the succion temperature. It is mainly used when we want to maintain different temperature from different coil in a system succion line. Therefore in this application you seen to refrigerate a same room, with the same TD at the coil.

truly yours

[Gary]

Another reason to use an EPR would be to maintain a minimum coil temperature in order to keep humidity high.