Bermuda

[Gary Stevens]

Can Any one help?
I have a freezer walk in with a heatcraft coil (14,300 btu) and someone has put a coplematic compressor LAHA 032 (rated at 11,200btu) . The box is getting complety frosted up, my head pressure is low and same with back pressure. The valve is sporlan 1 1/2 zp, should I be changing it to a 1 ton. I believe the compressor selected is incorrect , it should be a little larger? HELP

[jpsmith1cm]

A few more details would be helpful.

Simply stating "back pressure and head pressure are low" means little.

What, exactly, ARE the pressures?

While you're at measuring the pressure, take superheat at the evaporator and take a peek at the sightglass for me.

[jpsmith1cm]

Additional thoughts while you're checking the unit again.

What controls the temperature?

What controls the defrost?

[chemi-cool]

Texv is ok, compressor is too small.

The right compressor should have the desire capacity at -25°C evaporating temp.

[FEISTY]

Going on the information you provided, the compressor is too small for the coil. Make sure ALL the equipment is properly sized for the box itself. My rule is matched evap/compressor plus or minus 10% . Review the load requirements and change the compressor to a closer match. Go from there.