Hi Friends,

In Datacenters with low thermal load we can observe humidity control issues. The relative humidity at the room have a high variation (humidity swings) on a short time.
I have observed that when the precision air condition equipment are on cooling or dehumidifying mode (compressors on) the RH stays Ok, but when the compressors turn off by setpoints the RH rises quickly.
I know that with this scenario (units that are oversized for the heat load) will cause this situation, but I would like to understand better by psychrometry why this happen and what can be done to reduce the humidity swings.

Thank you.