Humidity goes up with temperature in split ducted system

[multivits]

Hi There Forum,
In our main large clean room we often see that the relative humidity goes up when the air temperature drops and I'm familiar with the reasons for this.

But we have another room with a split ducted AC system that has a reheat coil on the supply air, when I look at the graph it clearly shows humidity rising with and tracking with the rise in temperature in the room and I'm trying to understand the physics of this.

Is it because the air is enclosed within a duct and that the moisture can't really escape from the air unlike the larger open clean room space?.

TIA
Multivits

[beenthere]

Probably because the evap coil is not dry when the heat comes on after a dehumidify call.

[multivits]

Probably because the evap coil is not dry when the heat comes on after a dehumidify call.

Thanks for the reply, I'm not 100% sure that the system has a dehumidification function and will check to see if it does and that it is enabled.

[multivits]

Thanks for the reply, I'm not 100% sure that the system has a dehumidification function and will check to see if it does and that it is enabled.

It's confirmed that this split ducted system has no dehumidification function.