Zero Knievel Posted June 8, 2015 Share Posted June 8, 2015 I'm wondering if there's a better, cost effective, solution to this problem than what I'm considering. Basic problem....condensation in ceiling duct work during winter...notably if we shut off the central heat and go to gas heater (too cold for a heat pump to effectively warm the house). Aside from the normal drippage and vent staining, it's starting to damage the ceiling in some rooms. I know vents can me cleaned/painted as well as the ceiling (for staining), but the goal is to stop the condensation issue outright. For some reason, when the gas heat is being used, humidity actually goes up (don't know why as wood heating actually dried out the air). My suggestion is to run a dehumidifier during the winter once humidity levels in the house get over 50%. Mom hates the noise of a dehumidifier (it's not that loud). I'd suggest putting the unit in the bathroom with the worst issue and letting it run at every opportunity to suck excess moisture out of the air. At least then the noise is lost in a corner of the house she normally isn't exposed to. Let it run all day, turn it off at night or when using the bathroom, and leave the central air with the fan running so air is circulating through the ducts. I also think there may be better vents that combat condensation issues. Mom believes more insulation on the existing duct work would solve the problem. I say it won't because insulation only reduces how fast heat bleeds from one side to another. Where condensation is concerned, once the duct work is the temperature of the outside air, the amount of insulation no longer matters. Anyone else found a better way to combat this problem? Quote Link to comment Share on other sites More sharing options...
Mikey Posted June 8, 2015 Share Posted June 8, 2015 JoWhee is really your guy for this. He knows stuff....he says anyway. Quote Link to comment Share on other sites More sharing options...
Furbird Posted June 8, 2015 Share Posted June 8, 2015 (edited) Looks like mom knows best:http://www.insulationinstitute.org/blog/performance/moisture-accumulation-ducts/#.VXXizUaNhXkhttp://asm-air.com/airconditioning/condensation-on-ductwork-sweating-ducts/ Edited June 8, 2015 by Furbird Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 8, 2015 Author Share Posted June 8, 2015 (edited) Hmmm. The issue is, how much will be enough? I still think we need to run a dehumidifier to reign in the amount of moisture in the air. Parents are home all the time, but I can smell the moist in the air as soon as I get home. I'd run a dehumidifier upstairs year-round...at least keep it about 45 percent. They don't want to do it. As much as I'm not a fan of hardwood floors, I'd go that way in my own place. Wall-to-wall carpet is nice, but if you don't live in an arid climate, it's a nightmare if you have mold and mildew allergies (as I do). Edited June 8, 2015 by Aunt Sylvia Quote Link to comment Share on other sites More sharing options...
TuffguyF4i Posted June 8, 2015 Share Posted June 8, 2015 Run the dehumidifier. To have over 50% RH in the winter is a ton of humidity. 1 Quote Link to comment Share on other sites More sharing options...
JoWhee Posted June 8, 2015 Share Posted June 8, 2015 I don't know where you live but I'm assuming NY or New England. Condensation means high humidity, and a cold surface. Fix one or both and the problem goes away. If you don't fix this you'll get some nasty problems like mould. If you're running a gas furnace it won't do much for dehumidifying because newer systems don't use your breathable air for combustion, they normally have their own air supply. Wood stoves draw air from your house for combustion, they also burn hotter, both of which will lower humidity, unless of course they are pulling cold outdoor air in through your ducts. Have you thought about an HRV? It should solve your problem. It would draw in cool dry air, and heat it via an heat exchanger, and also filter the air while its at it. It can also be hooked up to your existing duct work. They aren't noisy, and they require minimal maintenance. Quote Link to comment Share on other sites More sharing options...
Furbird Posted June 8, 2015 Share Posted June 8, 2015 But if you properly insulated the ducts, you wouldn't be able to smell the humidity in the air, because it would never be in the ducts to begin with.I live in Mobile Alabama, verified as the wettest city in the US, and we have ridiculous humidity down here. I've never had a sweating duct problem (sounds like a good name for a band) but all HVAC is wrapped here with some serious insulation. I could probably fill my pool with all the water dripping off of the AC drain though. Quote Link to comment Share on other sites More sharing options...
DBLXX Posted June 8, 2015 Share Posted June 8, 2015 You got the answer in Fur's post but still refuse to believe it. Kicking the tires again? Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 9, 2015 Author Share Posted June 9, 2015 But if you properly insulated the ducts, you wouldn't be able to smell the humidity in the air, because it would never be in the ducts to begin with. I live in Mobile Alabama, verified as the wettest city in the US, and we have ridiculous humidity down here. I've never had a sweating duct problem (sounds like a good name for a band) but all HVAC is wrapped here with some serious insulation. I could probably fill my pool with all the water dripping off of the AC drain though. The only reason I "smell" it is my allergies. I can smell mold and mildew at levels most people don't notice. Moisture does great for carrying those spores through the air. You got the answer in Fur's post but still refuse to believe it. Kicking the tires again? No...just making sure every base is covered. More insulation WILL NOT combat humidity in the air. JoWhee, the HRV looks interesting. I'm not sure if it's what's needed...given the cost and how often it would be used. Might be cheaper to just rely on a dehumidifier on the high humidity periods when we run gas and put in extra insulation. Do they make better ducts that resist condensation staining the ceiling? All the condensation issues stem from water from the vents bleeding into the drywall. We have no issues with it appearing on the ceiling itself. Quote Link to comment Share on other sites More sharing options...
JoWhee Posted June 9, 2015 Share Posted June 9, 2015 Just fix the damned air infiltration, duct insulation may solve your condensation problem, or it could make it worse, i.e. mould growing in the insulation. It will also lower your energy bill by having no infiltration. Quote Link to comment Share on other sites More sharing options...
CBRXX Posted June 9, 2015 Share Posted June 9, 2015 You say shut off the central heat (heat pump) and switch to gas heat??? Are you using an unvented gas heater? That would put a lot of moisture in the air. Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 9, 2015 Author Share Posted June 9, 2015 You say shut off the central heat (heat pump) and switch to gas heat??? Are you using an unvented gas heater? That would put a lot of moisture in the air. That is an issue. It works great, although I don't know why the moisture goes up...I'm presuming natural gas has a water component which is released as water vapor when it burns. Hence why I bitch at her to run the damn dehumidifier and suck it up (literally). She wants to have her cake and eat it too (no moisture issue but not listen to a dehumidifier run). Quote Link to comment Share on other sites More sharing options...
The Krypt Keeper Posted June 9, 2015 Share Posted June 9, 2015 you are fully aware that water vapor is a natural by product of burning natural gas right? So is carbon dioxide unless you screw up your system and not let in enough air which it will produce carbon monoxide. Ever noticed water trickle out of car exhausts? or maybe the possibility of water vapor hitting the cold air outside producing contrails from airplanes or even your bike? Would say car, but we all know the energizer bunny doesn't do this in a prius 1 Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 9, 2015 Author Share Posted June 9, 2015 I figured water trickling out of car exhausts was more about dampness in the system before startup being blown out. Quote Link to comment Share on other sites More sharing options...
CBRXX Posted June 9, 2015 Share Posted June 9, 2015 I think the excessive CO explains a lot. Hope you're running CO detectors. I would not want my primary source of heat to be an unvented appliance. I would suggest not turning off the heat pump, just supplement it if you must with the gas heater. Else, maybe see if you can replace it with a properly vented unit. I figured water trickling out of car exhausts was more about dampness in the system before startup being blown out. That's the moisture in the exhaust gas condensing inside the cold pipe, until the pipe heats up enough to not cause the condensation. 1 Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 10, 2015 Author Share Posted June 10, 2015 I think the excessive CO explains a lot. Hope you're running CO detectors. I would not want my primary source of heat to be an unvented appliance. I would suggest not turning off the heat pump, just supplement it if you must with the gas heater. Else, maybe see if you can replace it with a properly vented unit. I figured water trickling out of car exhausts was more about dampness in the system before startup being blown out. That's the moisture in the exhaust gas condensing inside the cold pipe, until the pipe heats up enough to not cause the condensation. We do run a CO2 detector, but you have to run the unit a long time before it poses a danger. We also only use it as supplemental heat when it's too cold for the heat pump to work effectively. The problem with running it in conjunction with the heat pump is that they cancel each other out. Once you reach temp, both will shut down. The best we managed is to run the fan to keep air moving through the house. Quote Link to comment Share on other sites More sharing options...
CBRXX Posted June 11, 2015 Share Posted June 11, 2015 OK another question... If you have forced air system, why are you running a heat pump that cant keep up in the winter when you have gas available? Just put in a gas burning furnace. Or maybe another option to supplement would be a small vented gas boiler feeding a heat coil in your air handler. Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 11, 2015 Author Share Posted June 11, 2015 Heat pump was there first. When things go below freezing, the electric bill goes way up. That's the norm (once aux. heat kicks in). We went to an un-vented gas heater when dad got too old to haul wood in for the wood stove (what we used to do). It works like a charm. I pushed when they last had to replace the heat pump to go with something that used gas for heating (or as aux. heat), but they wouldn't bother listening. Now we have a whole-house generator AND the gas heater tied to a 500-gallon LP tank out back. I knew from having my own place that heat pumps were useless (or crazy expensive) once it got below freezing and you are running on electric heat strips for warmth. They didn't listen. I'm pretty sure a gas furnace is more $$$ than they want to spend at this point since what they have does the job. Quote Link to comment Share on other sites More sharing options...
CBRXX Posted June 11, 2015 Share Posted June 11, 2015 Since you live there why dont you haul in the wood. Quote Link to comment Share on other sites More sharing options...
TuffguyF4i Posted June 11, 2015 Share Posted June 11, 2015 Wood heat would certainly dry the place out. Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 11, 2015 Author Share Posted June 11, 2015 (edited) In a way, we like wood heat, BUT.... 1. That means buying or cutting wood. Something we don't have the time for and are not sure is worth the money (unless you luck out and get it on the cheap). 2. The wood stove has to be watched, restoked, etc. every few hours to maintain an even burn. Granted, for overnight we'd stuff it good and let it burn out by morning (or perhaps use what's left to restart in the morning), but gas was easier. Set it and forget it. 3. Messier. 4. Gas takes nothing to fire up. I debate burning both (use wood every now and then), BUT the gas nozzle is right behind the wood stove. I believe a good ceramic block placed over it would protect against any fire/explosion hazard from heat exposure, and the gas heater/fuel line can be disconnected and moved away, but that's more work than they'd want to bother. I would have preferred putting the gas heater in a different spot so we had both options, but the parents are a bit short-sighted about how they go about doing things. Sounds like more work, but with home projects, you really need to ask if what you're thinking will pose an issue 20+ years down the road. Edited June 11, 2015 by Aunt Sylvia Quote Link to comment Share on other sites More sharing options...
JoWhee Posted June 12, 2015 Share Posted June 12, 2015 Geez I could have sold you a brand new 60000btu furnace cheap! I could probably have trailered it down this weekend, God knows I'm bringing everything but the kitchen sink to philly! Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 12, 2015 Author Share Posted June 12, 2015 Believe you me, if I was calling the shots when the old heat pump went, I would have done things very differently. Hell, I only tell my parents shit for about a decade, then when they find it for themselves act like nobody told them about it sooner. I don't know if they're being dense or just trying to get back at my sister and I for our teen years. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.