- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Coaching Changes
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
Mold near HVAC vents.
Posted on 7/27/25 at 8:47 pm
Posted on 7/27/25 at 8:47 pm
Any idea why this is happening? Is it normal?
6
Posted on 7/27/25 at 9:19 pm to goosenecktrailer
Condensation. Hot, humid air from your vented attic is likely leaking around your registers and condensing on the cold metal surfaces. I’m dealing with this as well. I’ve sealed several of mine with flex taped and 2 part HVAC spray foam (attic side). It seems to work, but I need to do the remaining registers and fart fans.
Posted on 7/27/25 at 10:08 pm to goosenecktrailer
I have loose fiberglass in my attic. I piled it over the vents real good.
That seemed to help.
That seemed to help.
Posted on 7/28/25 at 3:29 pm to goosenecktrailer
fricking sucks; me too. this damp nashville summer is killing me
Posted on 7/29/25 at 11:01 am to goosenecktrailer
Is the fan continuously running? If so you may want to set it to auto so it only kicks on when AC runs. I had similar experience. Went on vacation for 2 weeks and came back to mold around all registers. Had to have A/C disassembled, cleaned and sanitized. Had a UV bulb installed that will kill any one cell organisms that passes through. Also had to have all ducts cleaned. Was an expensive lesson for sure.
Posted on 7/29/25 at 11:08 am to BLP
Went on vacation for 2 weeks and came back to mold around all registers.
--
Did you have AC turned off?
--
Did you have AC turned off?
Posted on 7/29/25 at 3:53 pm to ItzMe1972
No, But we would've had this happen regardless due to fan running all the time. This happened a few months after we had central air installed. When AC cycled off the fan was blowing the condensation through the ducts. Didn't know this about the fan and lesson learned. Just thought it may be helpful for OP if his was set to run constantly.
Posted on 7/29/25 at 7:16 pm to goosenecktrailer
low airflow or oversized. Check for dirty coil causing excess temp drop and room air mixing with duct air at grill an causing the area to sweat.
Posted on 7/29/25 at 7:52 pm to Wraytex
Would a fan in the attic near the area fix this?
Posted on 7/29/25 at 9:43 pm to Bayou
Not if its either of the issues I mentioned. if you changed the unit and it';s running shorter cycles and not properly dehumidifying, then you can get an AC guy out and see if a lower speed on the blower can be tapped onto. Yes that drops the duct supply temperature leading to the other issue I mentioned but it does cause the unit to run longer and wring more moisture from the air and should offset that somewhat. You really need a tech out to measure your airflow and temp drops. Most techs won't get into airflow issues, they go right to sales mode.
Posted on 7/30/25 at 1:44 pm to goosenecktrailer
It's likely you're getting condensation around your vents due to poor insulation which is resulting in mold/mildew.
I had a home energy audit completed by the power company, CLECO. The contract crew they sent out put the home under negative pressure and found a bunch of areas where air was leaking from unconditioned space (attic, outside, etc.). They went in the attic and spray foamed around every register and bathroom vent fan among other things. They used the cans of spray foam and didn't charge me a dime. Check with your local power company to see if you can sign up for that.
I had a home energy audit completed by the power company, CLECO. The contract crew they sent out put the home under negative pressure and found a bunch of areas where air was leaking from unconditioned space (attic, outside, etc.). They went in the attic and spray foamed around every register and bathroom vent fan among other things. They used the cans of spray foam and didn't charge me a dime. Check with your local power company to see if you can sign up for that.
This post was edited on 7/30/25 at 1:46 pm
Page 1 of 1
Back to top
Follow TigerDroppings for LSU Football News