chilled water pipe -condensation in corridoor
chilled water pipe -condensation in corridoor
(OP)
32-floor building, condensation and ceiling damage by dropping water in the corridor. Maintenance contractor did a job for 10 floors that there was two shaft, sealed from the top with the aluminum bond sheet and treated with existing fresh air.(pressurized).then the only damaged insulation was replaced by form insulation(in affected areas) And sealed maximum visible holes on walls. Existing is fiberglass insulation. Yesterday I rechecked the site found again condensation stated on insulation, drops water on existing insulation. I took the temperature by laser thermometer on insulation, existing fiberglass surface temp=25C and new form insulation surface temperature =20c.
SPACE condition now =DB/WB 24c/18C.
SPACE condition now =DB/WB 24c/18C.





RE: chilled water pipe -condensation in corridoor
Keith Cress
kcress - http://www.flaminsystems.com
RE: chilled water pipe -condensation in corridoor
RE: chilled water pipe -condensation in corridoor
Is there a DOAS? is it working correctly?
Are any exhaust fans running when DOAS is off?
More information = better responses.
RE: chilled water pipe -condensation in corridoor
RE: chilled water pipe -condensation in corridoor
CFD is a little overkill, so get out your velometer and start measuring.
RE: chilled water pipe -condensation in corridoor
I have an ongoing problem building which, among other things, has condensate inside light fixtures. These fixture are a typical ceiling tile mounted fluorescent with a single plastic lens. They also happen to be in a waiting/reception room and directly adjacent to supply air diffusers. You can see the air flow pattern of the diffuser as the air crosses the light and cooling the lens to below the dew point.
I recently sat through an ASHRAE seminar about humidity control, in which the instructor detailed a problem building in southeast Asia. Turns out the building had lots of unsealed joints allowing unconditioned outside air into the building at night when the HVAC systems were shut down "to save energy". In one location, a portion of the ceiling had been taken down and through the hole, the investigator could see daylight.
To find your problem you need to thoroughly inspect every corner of the building (at 32-floors, I don't envy the task ahead of you), review design documents including sequences of operation and review operating procedures to find the source of the problem. If you have a access to a thermal camera, that can be a very useful tool. Then you can develop and implement a solution. Keep in mind also, there may be several factors at work contributing to your building's problems.
Can you clarify what you got here. Is the exhaust from the kitchen, garbage and toilets providing the heat recovery or is it exhausted separately?
What kind of heat recovery unit do you have? Does it use a desiccant wheel?
You didn't mention the age of the building, is this new construction or has it been around for awhile.
If it's new, did the ductwork pass leak testing? Are there holes in the ductwork (look for loose duct insulation)?
Just throwing ideas at you here. Up to you to play Sherlock Holmes and investigate.
RE: chilled water pipe -condensation in corridoor
Also confirm AHU OA dampers are open to correct position when AHU on. I have seen AHUs with OA damper stuck shut.
RE: chilled water pipe -condensation in corridoor
Now I presume that the system what you are referring is in the return air path as your question is not clear.
Does this happen round the year or is it seasonal.
If you have any layout.
Thanks
Reji
RE: chilled water pipe -condensation in corridoor
RE: chilled water pipe -condensation in corridoor
RE: chilled water pipe -condensation in corridoor
RE: chilled water pipe -condensation in corridoor
However if you think there are gaps in the insulation then suggest this should be rectified and then observed. Also you need to check the thickness of the insulation based on your heat gain/loss calculation if it is adequate to avoid condensation.