- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- 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
Condensation on Air Registers
Posted on 6/25/21 at 7:31 am
Posted on 6/25/21 at 7:31 am
I got my AC serviced recently and the old 2003 unit is running great and blowing ice cold air.
The problem is that the previous owners probably didn’t service this unit for years and now it’s blowing colder... which leads to the next problem - condensation.
The two vents closest to the plenum are sweating and I think the issue is humidity leaking in from the attic. They installed 6 can lights at some point right around the two problem registers and I know they can let bad air in from the attic. Plus they have a really old skylight that is uninsulated and gets insanely hot during the day. I’m sure that area of drywall is letting in a lot of unconditioned air as well.
My plan is to demo the skylight area (not touching the roof right now though) and put fresh drywall on my ceiling, then float, paint, etc. I also will get some of those Tenmat covers for the can lights to air seal.
I ran a dehumidifier to see if the humidity being high in the room is causing the sweating. Low and behold, the issue goes away with that. So I figure sealing off air leaks will at least be the first step to fixing the problem.
Thoughts?
The problem is that the previous owners probably didn’t service this unit for years and now it’s blowing colder... which leads to the next problem - condensation.
The two vents closest to the plenum are sweating and I think the issue is humidity leaking in from the attic. They installed 6 can lights at some point right around the two problem registers and I know they can let bad air in from the attic. Plus they have a really old skylight that is uninsulated and gets insanely hot during the day. I’m sure that area of drywall is letting in a lot of unconditioned air as well.
My plan is to demo the skylight area (not touching the roof right now though) and put fresh drywall on my ceiling, then float, paint, etc. I also will get some of those Tenmat covers for the can lights to air seal.
I ran a dehumidifier to see if the humidity being high in the room is causing the sweating. Low and behold, the issue goes away with that. So I figure sealing off air leaks will at least be the first step to fixing the problem.
Thoughts?
4
Posted on 6/25/21 at 8:54 am to bapple
Insulate the boots where the resisters are and the duct work. Many hvac people don’t do a very good job insulating ductwork. That will cause the biggest problem with condensation like you described. Also any penetrations insulate seal them up tight vent the attic space as best you can.
This post was edited on 6/25/21 at 8:57 am
Posted on 6/25/21 at 9:24 am to bapple
Sounds as though you have identified the potential source(s) of the problem, and the steps to correct it. Cracker also offers good suggestions on the boots and ducts. Also check for potential leaks in the return air ducts/plenum (under negative pressure) that could be pulling in hot, humid air from the attic into the air handler. Are the sweating registers closest to the air handler/supply plenum, i.e., shortest duct run?
What do you set your thermostat at? The colder the house, the higher the probably of warm, humid air that enters the house from whatever source reaching dew point and condensing on the cold registers. If you keep the house cold, you can can temporarily raise the temperature to 74 or 75 F to see if that corrects the problem.
You monitoring your house humidity? A properly sized, tuned and operating HVAC should be able to maintain a relative humidity of 50% or lower during long run times of summer.
What do you set your thermostat at? The colder the house, the higher the probably of warm, humid air that enters the house from whatever source reaching dew point and condensing on the cold registers. If you keep the house cold, you can can temporarily raise the temperature to 74 or 75 F to see if that corrects the problem.
You monitoring your house humidity? A properly sized, tuned and operating HVAC should be able to maintain a relative humidity of 50% or lower during long run times of summer.
This post was edited on 6/25/21 at 9:42 am
Posted on 6/25/21 at 10:19 am to bapple
Insulated duct work and around box.
Posted on 6/25/21 at 5:52 pm to bapple
Make sure all of your registers are 100% open, as this can also cause condensation issues.
Page 1 of 1
Popular
Back to top
Follow TigerDroppings for LSU Football News