HVAC Question - A/C Ducts in Finished Basement Condensation

[EGTuna]

We're having our ceiling replaced in our finished basement. They started today and completed the demo, and revealed (much to by delight) that some of the A/C ducts are condensing enough so that they won't lay any new dry-wall for the new ceiling until I take care of the sweating ducts. Understandable.

Internet research, and a few phone calls later, and I'm utterly confused as to how to proceed. Do I insulate the ducts? One guy I talked to said that won't work once the dry-wall is laid, and that I need a return duct installed. However, the interwebs suggest applying insulation, but it was kind of vague insofar as it wasn't discerning between exposed and non exposed ducts.

Since this place is a veritable fountain of info, I figured I'd pose the question to my fellow Cowboys fans. What's the best way to prevent condensation on non-exposed A/C ducts? It's been unusually humid and rainy this summer (in Northern VA), so that is part of the problem. But I obviously want to avoid future issues.

Thanks in advance for any and all replies.

 

[JohnnyTheFox]

I am just a DIYer so take this with 2 grains of salt.
Proper airflow through your system? Clean filter? Anything impeding flow of air?
Check the blower motor and fan blades? Working properly and just as important zero dust on them?
Evaporator Coil clean?

 

[Denim Chicken]

I'm not a HVAC pro, but condensation is caused by warm air contacting the cold ducts, so it stands to reason that insulating would prevent the warm air from contacting the ducts thus eliminating condensation.

 

[Runwildboys]

I think any return ducts would have to be inside the same drywall as the ducts. I think insulating the ducts would be your best course of action, as DC said, but maybe you should consult an HVAC company for their opinion.

 

[Longboysfan]

I think any return ducts would have to be inside the same drywall as the ducts. I think insulating the ducts would be your best course of action, as DC said, but maybe you should consult an HVAC company for their opinion.

Yes - there is flexible insulation to wrap the ducts with.
But the temp change from one room to another should not produce that type of reaction.
Unless your pushing really cold air through an area that is very hot.

 

[Runwildboys]

Yes - there is flexible insulation to wrap the ducts with.
But the temp change from one room to another should not produce that type of reaction.
Unless your pushing really cold air through an area that is very hot.

The ducts at my local Hooters are constantly dripping condensation, and it's a bit warmer up near the ceiling, but not hot......and yes, I've been up there on a ladder, helping hang signs and such.
I have to believe the air in the ducts is just that cold.......Maybe that's part of the problem here?

 

[nightrain]

ALL AC ducts need to be insulated (full coverage). One of the main purposes of AC is to remove humidity by condensing warm air via a cooled heat exchange, hence converting the warm vapor to liquid condensate that is to be removed to the outside or to a drain.

You don't want that warm, moist air trapped behind your wall to hit those cold ducts where the air will be converted to condensate and left to pool and create all kinds of health issues like mold.

 

[YosemiteSam]

I'm not an HVAC guy, but why would a return duct change condensation on the main duct? (ie, it wouldn't)

Condensation is caused when humidity touches something cool causing the moisture in the air collect on the cool surface. A return duct isn't going to warm the outside of the main ducting.

If you wrap the pipe so that the humid air doesn't come in contact with the cool ducting, it shouldn't condensate.

That "one guy" sounds like a scammer. I would call other HVAC guys and tell that dude to walk across a busy highway at night.

 

[EGTuna]

Thanks for the replies. Having a duct insulating guy come out Tuesday. If I tried to do it myself, I'd be worse than Steve Pelluer and Gary Hogeboom combined.

 

[lukin2006]

The ducts at my local Hooters are constantly dripping condensation, and it's a bit warmer up near the ceiling, but not hot......and yes, I've been up there on a ladder, helping hang signs and such.
I have to believe the air in the ducts is just that cold.......Maybe that's part of the problem here?

Is this how you pay for your meal, hanging signs? Thats funny...

 

[Runwildboys]

Nah, I was just such a regular at one time, and the managers there were so useless, I figured I'd help out.....and the view was always nice from up there.

 

[CouchCoach]

Have you checked the frapplewanger connection? If that's come loose, it can make the wanger sweat.

 

[Runwildboys]

Have you checked the frapplewanger connection? If that's come loose, it can make the wanger sweat.

I thought it was the Hooters girls doing that.

 

[lukin2006]

Nah, I was just such a regular at one time, and the managers there were so useless, I figured I'd help out.....and the view was always nice from up there.

 

[lukin2006]

I remember the auto thread, not much automotive help came either. Now not much HVAC help either...hmmmm.