Hi,

Wonder if someone could help me with this problem. We have a 90sf2 +4C coldbox. 10' ceiling height. This box has 3/4 ton of refrigeration. During our temperature mapping of the box (we are in biotech and this mapping is a requirement for validation), we saw several areas inside the box would dip below-1C. This is really bad for our products and render the cold box unseable. The mfg is saying that the evap split is designed for 10C and that the box is too much refrigeration capacity. Are there any options to reduce capacity without having to replace the evap/condenser? or just control the discharge air from the evap to say 2C-8C instead.? I was told that the orifice can not be changed.

Also, we think part of the undershot (setpoint is at 5C, liquid solenoid shutoff at 4C, compressor continue to run for 25 sec before shutting off.) was also due to the liquid solenoid is 25 ft away from the evap. Is there merit in this thought.? We calculated that about 20% of the refrigerant is in the line between the solenoid and the evap.

Thank you all for your input.