Excessive moisture on outside surfaces of air handler

[GJ]

When I pull my hand across the outside of our newly installed air handler my hand comes back wet. This is true on most of the upper surfaces of the unit. The installer says this is normal. I'm 70 years old and have had a lot of Air Conditioners both old and newly installed and I don't ever remember the outside of the AHU being wet. Is this normal? Also there seems to be a lot of cold air coming from areas where sections of the AHU are joined together. Would it be ok to use that "foil" ducting tape to stop this air from coming out from these joints?

Thanks

JW

[HVAC fella]

'When I pull my hand across the outside of our newly installed air handler my hand comes back wet. This is true on most of the upper surfaces of the unit. The installer says this is normal. I'm 70 years old and have had a lot of Air Conditioners both old and newly installed and I don't ever remember the outside of the AHU being wet. Is this normal? '

REPLY: It is frequent if thats what you mean by 'normal' . The surface of the airhandler/supply plenum has reached the dew point of the air which is why you have condensation on the outside of it. You need to apply some half inch insulation such as fiber board to the outsides.

'Would it be ok to use that "foil" ducting tape to stop this air from coming out from these joints? Thanks JW'

REPLY: Yes, but apply it when the surface is dry and at room temperature. Make sure its not duct tape because it will dry and crack then fall off in time. Use aluminum tape sold at Menards or Home Depot.

[Zyp]

I wouldn't use "any" tape bought from Home Do-Pot.

[<kjpro]

If you need tape, you need a new sheetmetal man. :-)