AC Drian Air Flow

I have a technical question for the group. I inspected an attic ac unit, everything works well. However cool air is coming out of a drain line, its not much air but it is strong enough to blow a fiberglass piece out of its way.

I believe it is a defect, however the building contractor along with his HVAC sub contractor say it is fine.

My logic is this, no conditioned air should esacpe the system no matter how slight, especially in the attic.

was there a trap in the line and was there a clean out tee. Its generally not much concern. Where was the air you felt any pics. I generally have more concern in a attic where the discharge line discharges to

Delete the message a repost. We’re seeing your image in ASCII

No trap, I’m unable to load an image. I have however asked the manufacturer, once they answer I will post the answer.

Must have been a “blow through coil”. This coil don’t need a p-trap. The trap is what keeps a pull through coil from sucking air from outside and allowing the system to drain. If it were blowing air it must have been a furnace or a trane positive pressure air handler. Witch dose not have a p trap. And would blow air not suck air from the drain. I am a licensed Hvac contractor with 25 years experience. Hope this helps.

Yea, and you know nothing about weatherization.
You know, what keeps the energy your HVAC equipment works on inside the building?

Air loss from this location (into this location) is a 200% loss.
You loose conditioned air by discharging a volume of air outside of the air barrier of the building.

This produces a negative pressure inside the building.
This results in sucking in unconditioned air through the building envelope “at the same volume” you are discharging from your equipment.

Your equipment must run longer, till that sucked in air has been conditioned and the thermostat shuts off. This could actually prevent the thermostat from ever shutting off.

You not only have energy loss, you suck in all kinds of crap like mold, radon, and moisture that turns to water when it meets Mr. Air Conditioner’s air that is below dew point…

25 years and this has not crossed your mind… :-k