Leaky Duct System

[rverde]

I was hoping someone could help me out with a leaky duct system. In my house when the heater is done blowing to achieve room temperature, I feel a cold draft coming in through the vents and cold air returns. So the temperature in the room drops and the heater kicks in again which adds up to high bills. I have been in my crawl space and attic to seal up gaps but I have not found the problem. I live in Indiana so during winter this is very uncomfortable. What are my choices to find this? I talked to a home energy guy and he said he could seal all the vents and blow a harmless smoke through the system to see where it is leaking. This doesn't seem that difficult but I wasn't sure what was needed to make this happen. Is this something I can do or should a professional do it? Any help is appreciated.

Rafael

[Ed Imeduc]

Not to sure just what you have here. Is all the duct in the crawl space and tight. Any vents open to the outside in the crawl space? is there a poly down on the ground there . insulation on the crawl space walls. The sill plate sealed down tight .. Check out http://aboutsavingheat.com/crawlspace.html

Does the attic have good insulation in it . good vents for up there?

Id say lets see what you can do here first then call some one. Post back in this same post and we can try and help.

ED ;)

[rverde]

Ed,

I have been working on this for about 6 months now so I have done some previous work. The crawl space has insulation on all the walls. There are 2 vents in the crawl space which I keep closed during the winter time. There are a lot of ducts in the crawl space and I have sealed them up pretty well. In the attic, I have ducts that I have inspected for leakage and last winter added extra insulation up there. The ridge vents were changed about 2 years ago that should be good. About 3 months ago, I had a guy come and do a blower test. It was unbelievable the amount of air that was being pulled through the vents and cold air returns. It definetely is not a closed system right now. :mad: I have been on a mission to figure this out but with no luck yet.

Rafael

[Ed Imeduc]

Out of the box here. We put registers in the duct work there in the crawl space and let them open winter and summer to heat the floors in winter and dry it out in summer. We never open any vents to the outside at all. You say the walls have insulation on them. Do you have insulation up in the joist space on the sill plate all around the home?
In the attic, I have ducts that I have inspected for leakage and last winter added extra insulation up there.

Id say look again up there. You said cold air came out of the register when unit is off. Now cold air falls so can it be comeing in from the attic.
Now you have a 6 mil poly on the ground??
The furnace do you have a make up air to it from outside? and fireplace in the home/

ED :thinker:

[rverde]

Ed,

The insulation on the crawl space walls is installed as in the weblink you gave me. The whole crawl space ground has 6 mil poly. The duct work in the crawl does not have registers like they do over there. I can double check the attic but I really doubt I will find anything else. Going back to my original post, would that suggestion about using smoke to find leaks a valid idea? Something I can do?

Rafael

[Ed Imeduc]

Yes for sure . There is one called Smokeys its clean non toxic. Might try a hvac shop there . Johnstone supply have them . If you can buy there wholesale.

ED ;)

[rverde]

I appreciate the help. I will give that a try to help me pin point where the leak is at.

Thanks!