Cooling and Humidity Control

DX unit unit

What's this?

Check with the manufacturer for the dehumidification specs of the unit unit under the loads you demand. You may have to upgrade or add some additional equipment.

Are you using a heat exchanger to cool the incoming air with the outgoing air? Give the incoming air more contact time with the heat exchanger, and the dehumidifier, slow down the flow.

It sounds as though the equipment is being asked to do something it is not rated to do.

14degC is legally too cold for a UK workplace where people are seated for any length of time, for instance. Try turning the required room temperature up a bit: 18-19degC, perhaps? The product air RH will certainly be lower at these higher temperatures with no additional dehumidification, and as a bonus the electricity bill will be lower and the occupants more comfortable.

I think this is a case of oversizing the unit for the volume of air. Perhaps increasing blower speed would have some favorable results, but maybe not.

If your condensing unit will permit, you might consider raising the suction pressure with an EPR valve. However, then you might experience destructive higher discharge temperatures or compressor short cycling on the pressure control. In that case post evaporator refrigerant liquid injection might be necessary.

Such modifications would surely void any warranties and would have to be done by a mechanical contractor on a time and materials bases because it would be pretty much experimental.

In any case a psychometric study will reveal the solution, money will cure the problem.