Fungus on the ceiling due to condensation.

[hollandhvac]

I am working on a project in a coastal and very humid area.
We have appartments here that are being airconditioned with a fan coil unit connected to a chilled water system.
When the occupant of the room puts the temperature too low (like 20 Deg C), we have a lot of condensation on teh ceiling in front of the outlet of teh FCU. As a conseques of this we get fungus.
We cannot do much about the environment, but are ther other ways of preventing fungus on the ceiling, even though the humidity remains high.

 

[Ziggypump]

Insulate the duct and fan coil unit. The unit is cooling down, causing the space immediately around it to cool, and condense water. Add insulation to create a buffer.

 

[MintJulep]

Sounds like your conditioned air is impinging directly on the ceiling, dropping the surface temperature.

The very simplest solution could be change the diffuser discharge direction.

Alternately, select a diffuser that entrains more room air sooner.