Floor Condensation

[Roni Litmanovic]

I have a client who lives in a residential building who is suffering as a result of condensation on his bedroom floor. Apparently, the neighbor downstairs runs his central a/c most of the day and from what I can tell, the concrete slabs are not insulated in any way, on either side. Can you guys help with possible causes of this problem and available solutions? Should the return plenums be insulated also? I dont think the neighbor downstairs has insulation anywhere.

Thanks,

Roni

[Rick Cantrell]

"Can you guys help with possible causes of this problem..."

To much moisture in the air


"... and available solutions?""
Dehumidify the room

[Scott Patterson]

I have a client who lives in a residential building who is suffering as a result of condensation on his bedroom floor. Apparently, the neighbor downstairs runs his central a/c most of the day and from what I can tell, the concrete slabs are not insulated in any way, on either side. Can you guys help with possible causes of this problem and available solutions? Should the return plenums be insulated also? I dont think the neighbor downstairs has insulation anywhere.

Thanks,

Roni

I think you have figured it out already. The room below is cooler than the room above. The concrete floor is cooler than the air in the room, the RH is high so it does not take much of a temperature differential to reach the dew point and allow condensation to form.

About the only solution I can think of, would be to run the A/C in the room that has the moisture problem. The A/C will dry the air (remove the humidity), this in turn will lower the dew point in the room and should stop the condensation or reduce it.

The return plenum does not need to be insulated, but it sure would not hurt anything.

[Matt Vozzella]

This is an unusual occurence. I mentioned it to my boss and his first thought was a leaky/split duct which is forcing air up against the ceiling/floor.

[DavidR]

You could have multiple issues going on here Roni.

It sounds like a classic case of building depressurization in a humid climate.

Have you recorded any temperature readings or any other data in this building?

[Raymond Wand]

A dehumidifier would be your best bet at removing basement humidity.

[Joseph Melbourne]

Similar problem, Monday I'm looking at a Condo with poured concrete ceiling. Problem, at night owner is saying water pours out of ceiling ???
I'm thinking it's condensation caused by conditioned air difference between these two units. One above the other. I remenber a thread discussing this problem, but searching archives, I can't locate it. Can anyone help me locate the thread. Thanks, love this site.