Humidity and condensation

[Nina]

Hi everyone,
I have a problem associated with humidity/ moisture/ condensation. I am working on a plant with multiple floors. All the floors are interconnected through a staircase and the doors are typically kept open. There are big open filter tanks on the main floor. Floor below has an electrical room adjacent to the tank walls and floor below has another space with pipes into the tanks and finally the basement has meters of water piping and valves with most pipes being insulated. There’s an existing supply and exhaust fan and ductwork directing about 600 CFM of air in and out of the below levels. Ventilation for the main floor is through a big intake louvre and exhaust fan during emergency. There are couple of dehumidifiers (with DX coils) added to the building in the basement one for the main area with pipes which recirculates 4000 CFM of air and another for the staircase which recirculates 1200 CFM. Currently, there’s noticeable watermarks on the ceilings and walls of the floors below and during spring and summer there is water ponding within the basement area.
I’m stumped because I am not sure why the condensation would happen even though there’s not a lot of outside air coming in and there is dehumidification for the space. I am not certain about the temperature set points on the dehumidifiers and I’m confirming that but assuming the DX coil is sized correctly for the flow of air, can someone help me out in understanding what may be happening here? Is it because of the open tanks above and pool effect? Is there enough temperature difference between the water in the tanks and the building temperature that is creating condensation?

 

[moideen]

Condensation happens when the temperature of a specific location falls below that of its wetbulb temperature of immediate surroundings. Condensation can also occur in dead air pockets where there is no proper return to the dehumidifier unit.

The problem with the world is that intelligent people are full of doubts, while stupid ones are full of confidence.
-Charles Bukowski-

 

[LittleInch]

Nina,

Your numbers are meaningless to a we have no idea about the size of the areas, temp of the outside and load of other details.

First thing you need to do is start monitoring humidity levels and taking dry bulb and wet bulb temperatures. Only then can you start to see where the waste is coming from.

Also monitor the fresh air intake.

What temperature are these open tanks? They could release a whole load of water vapour into the air.

Why not just close the doors into the stair case??

But humidity control is your aim.

Are the walls insulated?


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.