Duct Sealing - Updated -Aeroseal
This was an interesting thread for me. I had a problem and there was lots of debate and some good information. So, in the end I got my ducts sealed. There is lots of info in the thread but I will try to re-cap and what I did.
As a matter of background, we have a 40 year old house and over recent years have gotten new windows and doors, new furnace and A/C and, added significant insulation in my attic. All that and more to save energy and make our home more comfortable.
One continuing problem was the airflow to some of the rooms was somewhat weak and as a result I have to balance my ducts every Spring and Winter and even during the seasons depending on how hot and cold it would get. Even then there were still cold/hot (depending on the season) spots in my house.
I have access to only perhaps about 20 to 25% of my ductwork and used metal tape and mastic on what I could reach to seal the ductwork but, 75% of them were in the walls or in ceilings and I could not do anything about those.
I saw an advertisement for Aeroseal and it made sense to me. I called them and to my surprise, they were able to come out within a few days. I must say, it was surely an effort to set up the tests but it sure does demonstrate the shortcomings of my ductwork installation. To my amazement, when they sealed all the vents and did the pressure test, my ductwork had a leak rate of 254 cubic feet per minute (equivalent to a 48 square inch hole)....Hmmmm, no wonder the back rooms were cool, they were getting no air! Fortunately, when they finished the application, while not completely sealed, it was a mere 31 CFM (6 sq in hole).
It took all day to set up the equipment and do the pressure test and then the sealing procedure. When they injected the sealing compound, parts of my house became all fogged up. The stuff was escaping out of every crack and joint and leak in the ducts.
Once they were done, the Aeroseal process had really done a good job of sealing the leaks. I immediately felt a huge difference in airflow to all the vents and especially the back bedrooms and the vents furthest away from the furnace. The very next day, I was in the basement re- balancing the ducts, closing some dampers and opening other dampers, and because the basement work areas vents were always closed off, I noticed how cold it was down there...a direct result of no leaking heat, I had to open a vent.
Today, I am very pleased with the outcome. I have proper airflow to all my rooms and I know when I “tune” my ducts from now on, the rooms will be the right temperatures and get sufficient airflow. One of the good things is I seem to have stopped heating wall spaces and ceiling cavities. To be honest, it is too early to tell if I will save any money on energy costs but, the comfort level of my home is significantly better than before the Aeroseal treatment and really, that is, to us, as important.
There is one thing though. Like I said, I have an old house with 15 amp circuits. They have to plug in a lot of stuff, fans, generators, compressors, heaters etc. Lots of equipment. This overloaded some circuits and the breakers popped. We had to find different circuits to plug into so we had extension cords all over the place. they need to get equipment that doesn't draw so much power.
I am pleased with what it did. It ain't cheap and may not be cost recoverable but, the comfort level in my house is so much better it was more than worth it for me.
So, in my job jar one of the tasks is to seal my old ducts. I have, over the years, gotten a high efficiency furnace, extra attic insulation, new windows and doors and there are still cold spots in my (fairly) old house. The next step was to seal the ducts to ensure the heat (and AC) gets to those areas.
I have used some metal tape in and around the furnace ducting (close to the furnace) and was going to buy some mastic and do the other joints soon. The thing is that only about 25 to 30% of the ducting is really accessible to be able to seal it properly.
So yesterday, in amongst the junk mail, is a local company selling a product that seems to be perfect for me. The product is AeroSeal. http://aerosealcanada.com/
A little research and I found the product and process getting awards and good comments, other than the cost. The cost seems to vary greatly. (and yes, I did search the forums and there were a couple older posts without much discussion or debate).
As everyone is looking for ways to save energy, ensure proper ventialtion in their living spaces, even many threads on curing hot and cold areas of the house (and yes, I am a big proponent of balancing the ducts and do thios regularily in my house), there may be other alternatives.
It seems to me that Aeroseal may be a good soloution to seal the areas of the ductwork that I cannot access. I am wondering if anyone has any experience or comments or knows of any one who has used this product?