Has anyone done Aeroseal?

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We're pondering this as an option for our horrible HVAC system and we're wondering what people's thoughts were on it.
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  • What exactly is wrong with your HVAC system? Aeroseal plugs holes, and that may be the issue you have, but, is that the real issue your having? This product claims to fix leaks, much like the system used to fix your tire that is flat. It sends in a gummy material that will coat the inside of your ducts, much like that of the tire and were the air continues to leak more is deposited in that location until the leak is filled. Sounds great? No so much. Your adding a chemical product in your ducts. There has not been enough information about this product in regards to outgassing or odors. Air delivery to each room can be effected by leaking ducts. That is a given. However even with leakage, the overall delivery of air to the rooms will not change all that much unless the leaks are really large. Those will not be sealed using this product. The hole sizes that are large enough to really change comfort delivery simply cannot be filled by this product, requiring a hand sealing system. If you were to go that route, for just a few locations, you might as well save a thousand dollars and have it all hand sealed. I have found after doing duct repairs and comfort improvements in dozens of homes is that in more times then not, its duct sizing, air leakage of the home, poor or improperly installed insulation both in the home and on the ducts and incorrectly sized equipment. So what exactly is going on and what are your complaints regarding your system? Your first order of business is to determine exactly what is going on in the house. This is not limited to just the duct system. Have a professional energy audit performed using a blower door evaluation and a duct blaster test. These two combined tests will determine exactly what and where repairs and improvements are needed. These tests will give you bench marks for future repairs so you can retest after work is completed to determine exactly if your work has accomplished its goal in the end.

  • Thanks for taking the time to respond. My issues are lengthy but I'll try to keep it brief. We bought a flip last year, a two flat converted into a single family with a black rolled flat roof, no attic, Chicago. There is a basement and it's finished, so all the duct work is within walls. New furnace (in basement), new a/c unit (on the roof), all new ductwork. We're not getting any heat or a/c on the second floor where the ducts/registers are in the ceiling. If you get up very close, within inches, you can kind of feel a tiny tiny whisper of air, but not enough to have any affect at all. And by that I mean not at all. The first floor is always comfortable. In winter, our gas bills were insane and the upstairs was a full 25-ish degrees colder than the first floor. Now in the summer, it's the opposite; a full 20+ degrees hotter even with the a/c, and still crazy bills. We have to have the windows open upstairs while the a/c is on or we'll die of heat. Dr. Energy Saver was just out after having two other companies come look (to no avail; they didn't test anything, just walked around and the second one cleaned the ducts) and this guy went around with his scopes and tools and heat reading things. He was going to do a blower test but changed his mind for some reason, likely because he had been here for over two hours at that point. I suppose I could ask him to come back and do the blower test. He affirmed our suspicions that there's no insulation at all in the second floor ceiling, which is problem 1. Because it was a flip, he suspects the duct seals weren't done well, hence the Aeroseal suggestion. The only accessible duct work is in the utility closet with the furnace, so nothing can be done by hand. I realize if the holes are big, they won't fill, but maybe something is better than nothing. Ultimately though, the system of ducts was likely done all wrong by some schmoe off the street. We have to do something because a.) it's very uncomfortable b.) our bills for gas and electric are unbearable and unsustainable and c.) we won't be able to resell with such a huge problem.

  • Doing the duct sealing will not solve this issue. The air leakage amount that the duct sealing will fix is not going to be enough to solve anything. Get a Duct Blaster test done. The blower door evaluation also will show you where air leaks in the house are, but you need to know exactly how poor the air leakage is in the system. Most central ac systems with furnaces in the lower levels having to deliver air to the 2nd floor do not cool very well. Have your roof painted with silver roof coating. This will reflect heat gains and radiant heat that is coming from the roof. I assume there is a small cavity between the roof framing and the ceilings below. Normally that is how they are built. Most of the heat gain is due to radiant heat moving though the materials after being absorbed by the dark color roof. In any case that will help. Because the ducts are not accessible even if they were air tight, they are picking up heat also. So what little air that comes out ends up being heated by the gains in the cavities where they are located. There are some work around things you can do. If the duct supplies are all separately sent up to the upper levels, a HVAC contractor can install a damper system that will shut off the lower levels as they get cool, so all the available air is being delivered to the 2nd floor. Another method of repair is to install a mini-split ac/heat pump system on the rooms upstairs. These systems now are about twice as efficient then normal AC systems such as the one you have now installed. They are not cheep, but based upon your current operating expense, you should get this back in no time in savings. Before you do anything else, I would suggest that not only you get the duct blaster test performed, but that the house be both sized for the heating load and duct design sizes. This is called a Manual J and D. This will inform you of exactly what heating and cooling loads and sizes are required to heat and cool the home properly. The Manual D will provide you with the correct amount of air supply that is required in each room. Armed with that information, you will be able to determine if even if the ducts are the right size for the area needed to be cooled. You can have a perfect installed duct system, but if its undersized its simply not going to heat or cool correctly. Another thing to look at is the sizing of the blower system for the cooling side of the system. Blower fans in furnaces have different speeds and capacities, If the blower size is incorrect, or set on the wrong speed this will cause all sorts of issues with the systems performance. If your planning to flip, I would go for the mini-split system. This is a add on improvement that allows you to determine the exact temp in each room that the indoor unit is located. Just do not spin your wheels in hope that sealing the ducts will solve your issues. Most cases it will do nothing that is measureable enough to make a difference. While in a correctly installed system you may see an improvement in savings, its not going to solve the issue your having with no or low flow. Do not let them convince you otherwise. Painting the roof silver will help a lot with comfort. Reflection of the suns energy will cool the ceiling down quite a lot. My number is on my profile, If you want to speak to me, please feel free to call. If I am not there, leave a message and I will call you back shortly after. Evenings are fine.

    • So far I received his estimate which was something to behold: $9200. That's $2195 for Aeroseal, almost $1200 to seal 11 can lights and replace with LEDs, $1000 to cut a 14" channel in the ceiling from house front to back on the second floor (does not include patch and repair) and then $4800 for both expanding foam and cellulose blow in, average depth of 18". Needless to say I almost choked. I emailed him back and asked him to come do the door blower test before any more discussion. I don't think a manual J and D are a part of their free energy audit, but I'll ask when I hear back. Wouldn't it be enough to just do cellulose? I understand the premise of expanding, to seal up hard to reach areas, but it seems a tad overkill. By the way, I don't think we could install mini splits as our 1890's brick house has very thick walls plus that might tip off a future homebuyer instantly that there are big problems. And what's the point of central a/c then. We do have dampers but when we close the first floor, it has no effect on either the first or second floor. We've tried it all. Thanks so much. I'll be back with his blower results hopefully next week.

  • Thank you very much for all your input, I really appreciate it. We were planning on painting the roof silver at some point but as the roof is inaccessible without a ladder, we haven't done it yet. I'll call the guy back and have him do those tests. I'm still waiting to receive his estimate for blow in insulation and the Aeroseal. He also suggested sealing the can lights on the second floor, by the way. Thank you too for offering me the chance to speak to you. I'll be back to this conversation at the least when I hear from the guy.