Homeowners face condensation problems with ductwork

“What could be causing it? Live in FL. Usually keep A/c turned down to 65. It dosen't get down to 65 by the thermostat reading. My regular HVAC tech says nothing is wrong? submitted by /u/akg81 [link] [comments]”

“I had a damp rid bucket in a closet on a shelf, it had a crack in the plastic container and as it was filling it seemed to be slowly leaking onto the wood floor below, it wasn't until it ended up diffusing outside of the closet that I noticed there was a problem due to oily floor feeling. The company says it has to be displaced with cold water and then wiped up with towels. This doesn't even seem like a viable solution with wood flooring. I have put a dehumidifer in the room because usin”

“Found out house has been running at high humidity 70 percent plus for a while now due to a duct leak in the crawl space. The hvac has always still stayed pretty cool just taken longer to get down to the set point. I Opened the ceiling vents and I saw some black on the wood but can’t tell if it’s just dirt, I also opened the return vent and this is where I’m pretty certain of mold and it also smelled like cat pee. I tried to open the unit outside and look at the evap coil since it’s a package uni”

“We have an old house that has a 1/2 basement & 1/2 crawlspace. The crawlspace is unsealed (can see the dirt) but doesnt have any vents outside. The moisture really rises in spring & fall due to living in the midwest. I thought about getting an allorair HD35P to suck out the moisture until we can afford the enclose it. My plan is to have it in the vasement half & try to aim the exhaust near the entry point into the crawlspace to try & push that dry air into the crawlspace. Would t”

“Is there anything wrong with the ductwork in my house? We have an American Standard unit and are dealing with humidity issues in our 1941 home that has caused a portion of plaster ceiling to drop to the ground, and tenting in the hardwood floors. A technician came out today and realized the minimum coil temperature was 28 degrees and changed it to 42. He said everything was properly sealed, although a contractor before him said he felt they might not be sealed properly because of the tape. Pleas”

“I'm in Florida. Our area has had heavy daily rain for August and September until this last weekend. A month ago, our bamboo flooring started buckling in the middle of the house. I looked and our humidity level was 78%. We've looked for leaks. My husband checked the crawl space, none of it is a problem. We've been running a dehumidifier. I've gotten it down to 65% on a good day, but that's it. We installed a Goodman heat pump a few years back. A retired AC guy checked our work”

“Hello everyone! First time homeowner and first time posting here. I moved into this house recently and duing the hot days, I noticed that there were some water leak marks on the ceiling of the kitchen and the living room. I thought a water pipe was leaking but when I opened a hole through the ceiling drywall, turns out that the a/c ducts were right there and were sweating because they are not insulated. They run through the ceiling and goes out to the floor vents of the 3 bedrooms upstairs. The”

“Follow up post now that we've opened up the ceiling. This was the second summer our living room ceiling had condensation seeping through from our ducts. We've had the furnace and AC unit inspected by multiple folks and everything checked out fine. Wondering if anything visually looks "off" here? From an untrained eye, only thing that stood out to us were all the nails poking through the floorboards above. Could a shotty contractor pierced through the ducts causing this issue? &”

“I am a plumber but don’t know much about hvac. This is my grandma’s home in Marietta GA that was built in the 40s-50. I replaced some cast iron for her that had rotted out and noticed while I was down there that ALL of the insulation on her duct work was soaking wet. It was also steadily dripping off the duct work right off the back of the furnance. What is the fix for this? She’s got a workshop in the basement where the furnace is then there’s a crawlspace area up past the retaining wall. Does”

“1600 cfm 14 inch duct leaving furnace, 12 inch going into furnace Appears to be 20 inch in crawlspace with 6 inch flex duct to floor registers Hvac Guy recommends replacing entire units with completely different units. Is there a compromise? Replace the blower? Something similar? submitted by /u/Any-Buffalo-4436 [link] [comments]”

“I’m in South Florida and having a recurring condensation/sweating problem around several AC supply boots/cans in my attic. The attic is extremely hot/humid, and I have four supply boots/cans that are sweating enough to be a concern. What has already been done: HVAC company sealed the boots to the ceiling/drywall. Duct connections were sealed/masticed. The mastic work appears reasonably good. I’m still getting condensation. I know the attic-floor insulation is either low, uneven, or miss”

“Hello all, Thanks in advance. Came home from a long weekend to find a giant puddle on the ground and messed up drywall. Went into attic and discovered condensation excessively dripping from one of the duct union(?) where several ducts meet at the a/c. Everything I've searched so far is saying possible bad duct insulation. I did feel some cold hair escaping from where duct meets a/c. Is the solution just to insulate around the cold air? And why would this just occur now. Attic door was shut,”

“I noticed one of registers is exposed and has moisture on it. In Houston so it’s hot and humid. I’m assuming they cut a hole and didn’t cover it with insulation. Should I just wipe it down dry and then put insulation in this hole to cover it up so hot attic air doesn’t have direct access to this? Yellow fiberglass or regular Batt insulation? The moisture doesn’t seem to leak to the drywall but I want to avoid anything in the future. submitted by /u/AirDependent [link] [comments”

“We have discovered that the ductwork in our walls of the second story have been dripping condensation from the outside into wall cavities. The ducts come out of unconditioned air in the attic and there is insulation around where they enter the home and the ducts themselves are insulated. Needs solution as we are having to rip out walls due to fungal growth. Any suggestions are most appreciated as our HVAC team had no ideas submitted by /u/Ghost_vaginas [link] [comments]”

“Hey everyone. I’m wondering if I can instal a dehumidifier directly into the closet that houses my air intake handler (not sure if that’s the right words). 1500 sq ft home. Double wide manufactured home. Floor registers, hard ductwork that is in the “belly” of the house. No crawlspace, just plastic underpinning. Only intake is on the unit itself, door has a large vent on the front for airflow. I’m worried that it might affect the static pressure in the closet? I figured installing there would be”

“Alright HVAC warriors, we moved into this house a year ago. The a/c is in crawlspace. Supply is coming through floor vents. Registers are metal and ghost sweating like it’s their full time job and growing mold ( that I just found ) I’m assuming because we keep it at 70 and outside is the surface of the sun hot and the humidity is breaking records. Oh and they’re not SEALED. Ugh. I was told by Google to foil tape these to seal them and keep them from sucking the crawlspace air in. Is this an acce”

“New construction home and we did our final walkthrough with a knocking noise coming from laundry room. Builder tried to say this was normal and all their homes do it. They explained it as condensation dripping off the A/C unit in the attic. I currently live in one of their homes and have walked through maybe 30 others during the build process and only hear that noise in my home. Any idea how to fix it or what needs to be done. The inspector flagged it and we brought it to their attention but the”

“Oook. Last year we replaced our ancient AC and furnace with a new furnace dual fuel heat pump thingy. This summer I noticed that an area in the upstairs ductwork started sweating, because there was water damage on a wall and part of the ceiling. I have no attic access. It is small dead space. I am getting MANY different recommendations from companies. One company suggested installing a damper, which makes sense to me, but i also don't fully understand 🤣 Another company said the rip open the”

“We have a single-family house with a furnace in the crawl space and we have another in the attic. We live in a high-humidity area and there's definitely a lot of condensation in the crawl space. There is some growth on the outside of the plenum as well as on the inside, a bit in some of the ducting. It was advised to install UV lights in the plenums. It was suggested to put just a UV light in the attic unit and the option was given to install a UV light with a carbon filter in the crawl spac”

“We have a 3 year old house, 2 stories, with ceiling vents. Long story (kind of) short, is that the insulation installers barely insulated above one of the bedrooms and loft (both facing west), which caused condensation to drip from the vents in those rooms. After several redirects by contractors doing assessments, which led to some lengthy conversations with our builder, they got the installers to show up Wednesday morning. They spent about 20 minutes in the attic, and left. The bedroom doesn’t”

“Recently moved into a new house in southeast Texas. Ever since summer started, condensation has been building on everything connected to the attic — light fixtures, vents, and inlet ducts. I found out my HVAC system was pulling in outside air and mixing it with the cool indoor air, which caused the problem in the pic. I cut and capped that line. Do I need better attic ventilation? More insulation? I keep the house at 68°F and we’re having 100°+ days. I had someone inspect my HVAC and they said i”

“I have a flexible duct in a walkout basement that is sweating and we're getting mold with it, so that's not great. It's the only duct that is wet. There are no plumbing leaks and we haven't had rain in at least a week so I'm certain it's condensation. I had an HVAC tech come out and replace the duct two days ago and the new duct was wet this morning. I took a picture of the condensation on the trunk where the duct connects. I noticed that he used the same strap in one loc”

“I have a drain line in my crawl space that is dripping wet with condensation. I wrapped it in two layers of K-Flex and it is still dripping wet. Any ideas what I should do to stop this? submitted by /u/takeluckjake [link] [comments]”

“I just noticed some condensation outside of my furnace/blower upstairs. It is an exceptionally hot day here in chicago so it is running alot today to keep the house cool. I am not sure if this new or if it is something that has been happening and i’ve just never looked at it. Any advice? Thanks, submitted by /u/PriorMuch9225 [link] [comments]”

“The A/C at my shop been leaking for a month or 2 now, not constantly and not alot but it dribbled down enough to destroy the ceiling tile at that spot and I don’t want to replace them yet until it’s fixed. It’s a dual Hvac system and the spots I circled are the spot that the leaks are coming from. The landlord got the Hvac ppl came in like twice to check it out, idk what they did they didnt go into details about it I just saw them switched out the refrigerant the last time they were here. They t”

“Hi all. As the title said. I think I’m dealing with some extreme sweating from the A/C ducts. Didn’t notice anything crazy but came home and noticed bubbles on the wall around where the duct comes from the blower and out to the rest of the unit. For reference, we are in a condo in an older building (1929). It was a warehouse and converted to units in 2000. We purchased in April of this year. The ac unit has functioned as one would expect since we moved in and throughout the summer. We never noti”

“Hey all, I've been battling this issue for a while with my HVAC company. I have a horizontal mounted HVAC system in my crawl space. Per the video, it has a slow drop from the condensate line. The humidity under the house a month or so ago was off the charts, 90% plus, which was causing a lot of sweating and standing wanted from the system and the ducts. I put in a dehumidifer and its gotten down to the 50's. I informed my HVAC company and they insulated the plenum and threw tape and this”

“I am seeing water stain right above floor register. There is no water stain on the drywall above or ceiling. There is very minimal chance that there is any plumbing behind it. Some background about the house: older house built in 1958, there is a crawl space below but I am 100% sure there is no plumbing behind the wall. My guess is this is related to some sort of water condensation due to warm air meeting cold air out of the floor registers? I had my HVAC tech checked and he said there isn’t any”

“Closing on an older home Tuesday. There are several baseboard radiators in the home that have foam sprayed around them in an attempt to prevent water. I’m hoping to get some sort of idea how I would begin getting to the source of this issue and fixing it permanently (if I were to DIY it) or preferably, get an ideal ballpark of what it would cost for a pro to fix the issue. Absolutely any insight here would be appreciated. TYIA! submitted by /u/Inevitable-Soft-1161 [link] [comme”

“Having to tear out some drywall in my garage to run wire for a subpanel. In the process, noticed where the metal work is for the HVAC was dripping and the insulation is absolutely soaked about halfway down. It’s in the back wall of my garage where it meets the house, and the wall has been opened for a week. It is very humid/hot here and temps are 90+ so AC has been blowing nonstop. It’s likely condensation just from cold metal and hot air outside, but after I replace the insulation and the drywa”

“I have humidity issues in the house that started after a evap/compressor replacement. We were always a little high before the replacement, like mid to high 50s. After the replacement was 70%+. I could smell the mustiness from the crawlspace coming through the vents. The company blamed microbial growth in the ducts and poor air sealing of my house. Eventually I got a manager at the company that came to the same conclusion on his own, that my ducts were leaking somewhere and sucking in crawlspace”

“My condensation drain outlet for my heat pump is super closet my house and extremely close to the ground. The water it produces is crazy and always a puddle by my house even with a dedicated dehumidifier in the living space and one in the crawlspace. Any ideas on how to move the water to somewhere more appropriate? I do have a sewage access point close by, could I plumb it to that? Do I need a condensation pump and plumb it up into my attic and then to the washer drain halfway across my house? &”

“We had an addition to our home in 2022 to add a suite for my MIL. Today we noticed a wet spot on her ceiling in her bathroom. I suspected it was condensate right away because there is no over head plumbing and we have not had rain in the last few days. Upon investigation I discovered that #1 the shutoff device failed. I have never seen one of these things actually do the job of shutting down the system. But I also discovered that the overflow tray has a short piece of capped PVC and goes nowhere”

“Houston TX, 2018 build, Symptoms: Water dripping from the corner of the return enclosure at the hallway ceiling. Sheetrock around the vent has wet marks. Insulation around the return boot is wet to the touch. Drain pan is empty There’s a PVC line dripping outside. Not sure if it’s the primary or the secondary. No visible ice on the coil or copper lines. What I’ve already done: Replaced the filter. Old one was pretty filthy. Wet-vac’d the condensate line and the clean-out from the outside end and”

“First time home buyer here, brand new build in coastal South Carolina. 2200 square foot house, attic HVAC unit with dual zone heat/AC. After doing a more thorough walk around my house, I noticed some condensation forming on the bottom of my attic unit. I don't think any is dripping or running from INSIDE the unit. The attic is very hot during the day, and humid as expected due to the local weather this time of year. The water in the pan hasn't been tripping the water level switch or even”

“I realize that spraying water through nozzles to cool ambient air pulled through a condenser comes up fairly often here but nearly all discussion revolves around tap water which I realize will scale the coils. It seems to me that rain water or particularly condensate from the evaporator would be a better alternative. My goal would be to use it only during the hottest hours of the day during summer when ambient temperature is highest and humidity is lowest. The remainder of the day/year it would”

“I’ve lived in my house for over 20 years and a problem has just popped up. The return duct in my attic is getting condensation and leaking onto my ceiling. Only thing changed was installation of a completely new system last year in July. Any idea what is going on? submitted by /u/Local_Data_6921 [link] [comments]”

“This is an add on done before we bought the house. Its the roof of our bedroom. When we bought it it was cleared by the inspector. The AC handler is in the closet and noticed mold and wet spots in the top of the closet. The AC insulation was sweating and causing the problem. There is no way into the small "attic" area, and it wasn't used alot before we bought it. It sudde ly hit me 4 years later that should it have shingles to help with the sun. We cant really tell if it's prop”

“I have condensation building up on the PVC pipes near my HVAC system, and I’m also experiencing a leak caused by moisture getting into the area between my first and second floors. I’m not sure whether the moisture is coming from condensation on the PVC pipes, the air ducts, or somewhere else. There is no water accumulating in the drip pan. The airflow seems good, and I recently changed the air filter. The system is older, and I’m not sure when it was last replaced. I also don’t see any obvious l”

“Hello, I just moved to a new house, as the title says our AC coolant line is dripping just a little bit. I believe it's condensation, it just seems like water, not oily at all and when it dries it doesn't really leave any residue and it only drips when the AC is running. There's a small hole in the insulation around the pipe where the water drips out of; can I just patch this with some specialized tape or something? Or would it be better to replace the whole insulation? submitt”

“I recently had a large bubble in my ceiling which turned out to be a pool of water that had accumulated from condensation build up dripping from the flex duct line in my ceiling. Thinking this was a water pipe leak, the plumber was who found this, but he doesn’t think they should have used non insulated flex duct in the ceiling for the run to my vents. This is a new build, but out of the warranty period at this point. Does this look up to code? This space is the void between a first floor and 2n”

“I own a condo unit in a midrise condo and I have a combined furnace/ac in a closet off one of my bedrooms. I’ve noticed holes around the hvac hose/pipe penetrations into the drywall of the closet. I’m concerned that pests could come through these larger holes in the drywall that likely lead to a wall void to a neighbouring unit. How do I seal these properly? I have silicone caulk and steel wool at my disposal but can purchase any other suggested materials if needed. Thanks for your help. The pho”

“This is in customers garage. Fully expected a leak in the wall from pipes but turns out the duct has 0 clearance and is sweating only on the drywall side. House is 30 years old and only started happening the last few years... I know its because of warm garage air meeting the cool pipes. My only idea is to ripped off the drywall and tape the seams, then shim out the studs an inch and put insulation in. Think that would solve it? Or is there a better solution.. should I foam it or fiberglass it?.”

“I have water just pouring out of my ductwork. I’m running a dehumidifier but it’s old and not keeping up. It’s been really humid in Iowa but this is ridiculous. Is this more than just condensation? submitted by /u/ia-crow [link] [comments]”

“I had a wet spot showing on my garage ceiling with bedrooms above it. I saw two small older condensation marks running the same path, and assumed it was likely the duct. I cut out the section and the duct is extremely wet, especially the top. There was blown in insulation. I’m not certain this was the best idea because I have the AC going and now the duct is exposed to more hot air to condensate. I placed a call for an HVAC guy. Waiting on his call back. I don’t want to make this issue worse wit”

“Good afternoon, First-time homebuyer here. The inspection report for a house I’m looking at found that the HVAC system is dripping onto the vapor barrier in the crawlspace, which is creating puddles. The inspector measured the wood moisture content (MC) at 21% in that area. The house is in NC, so I understand that crawlspaces can get pretty humid during the summer. I was concerned about the water sitting there, so the seller had an HVAC technician come out and check the system. The technician sa”