Where is the condensate on pipe occurring? If it is on some portions and not others, look for patterns.
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.
moideen said:
Yes, there is fresh air unit with heat recovery. Exhaust working but for kitchen, garbage room and toilet.
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.