Inspected a local brew pub with some unusal HVAC/venting issues that I would be interested in a professional opinion on.

On humid days (and only during hot humid days) they have some water leaking from ducts and venting equipment. The worst location is the basement kitchen (huge commercial set up with 4 cooktops, 2 fryers, etc). Although I did not observe it, I am told that so much water was dripping from the vents that they had to rig up a makeshift gutter to run the water to the sink. It seems logical to me that since it only occurs on days when teh exterior air is humid that the issue must be related to the make up air system (a huge commecrial unit on the 5th story roof) but I am seeking professional thoughts on that..... There were some small (4 square inches) holes in teh duct work running from the intake unit on the roof down to the kitchen, but these did not seem large enough to account fo rthe mass quantities of water the manager decribes.

Other locations of dripping: The HVAC vent at the top of the stairs (possibly condensation from teh heat of the kitchen rising up?); A bathroom HVAC vent (located pretty far from all other concerns, but adjacent to the exterior brick wall and in a fairly isolated section of a large restaurant bathroom with 15 foot ceilings); and two exposed metal HVAC ducts at the front entry (possibly from entry air mixing with the greenhouse effect of the enormous picture windows).

Any thoughts? Incidentally they have had 3 contractors out to look at the HVAC system (not the kitchen venting and make up air, though, for some reason) and they could not identify the problem. Also, the brew room is totally sealed off from teh rest of the place with its own HVAC systems.

I welcome your input as I would like to offer some suggestions for the frustrated owners.....