20 hrs to cool down from 80 to 72 is not necessarily poor performance. At what outdoor temp? Without seeing job, I personally think you would be better satisfied and more comfortable with a separate system for upstairs and downstairs. Of course, I am certain ductwork would have to be reworked or probably replaced altogether. Second choice would be one larger system with zoning controls for each floor. This can be problematic on a redo like you are discussing and would require an experienced HVAC contractor. IMO

I felt the same way in terms of the "asbestos fear factory." But I had a contractor explain to me that the bigger issue is the cement dust (a carcinogen) that will be created once the interior coating on the cement wears off. He found that about mid 1960's built homes and earlier will be releasing cement dust. Easy way to check: rub your finger on the ceiling of the duct: if you have dark "smudge" that is clearly not house dust which would fall to the bottom of the duct...you have cement dust blowing into your house. My house was built in 1959...and there was definitely cement dust on my hand when I rubbed the interior ceiling of my duct. Plus there is the fact that the inspector called out the Transite ducts...and I just did not want to buy a house with any asbestos fibers not encapsulated. I am just sharing my experience and that I found Duct Armor to be a great solution...and they were definitely not promoting a fear of asbestos when I spoke with them which was refreshing. Cheers.

"Would this work?" I don't know how well it will work because I don't know how effective your protective measures will be. What I can tell you is (A) the marjoity of hvac technicians are under qualified for the job they perform daily,much less this type situation for which trade schools do not spend one minute on training. (B) your GC is either clueless or doesn't care,otherwise provisions would have been in place long before you brought it up. (C) Internet well wishers can only give you stop gap measures. To pull it off effectively require's educating you on the whys and why nots then you doing the same for your contractors. I truly would love to walk you through the process but it's not possible. If it were I'd get on the net to have people tell me how to play musical instruments,tailor make myself a nice suit,handle all my legal matters and overhaul the transmission in my car,,,,,,,,,in only one day for each. My best advice was in first post. So that you don't go away empty handed,after this is over and it's time to use system,use merv 8 or better filters and be sure to replace them often. Every new or newly remodeled home has collected a lot of dust in nooks and crannies despite best efforts to clean up.

Elmer's inquiry deserved more of a answer than your chest-thumping, self-promoting, California-bashing commercial. The climate around Katy, Texas is certainly not "one in a million." It's similar... Just "similar" but not exact... meaning different. Me and Mr. Fudd's disagreements are well documented on this board the story continually evolves from duck to rabbit season and back again. One in a million is a generalized comment... a saying. But you Mr. Ross love to find something to argue about for the sake of arguing. Distinctly different? That's rich. I find it humorous to what people like to nit pick over. It doesn't change anything. I don't change anything about the comment I made. You can disagree if you want, I still say Katy, Texas is indeed "one in a million"... at least. Ray is a one-person company. He lives in the replacement contractor world. When someone is without heat, air conditioning or hot water, it's often the first replacement contractor to arrive that "wins." Not hot water... I am not a plumber. Texas licensed for AC and heat only (HVAC). Yes essentially that is the "service" I offer as well as the part of the world I live in. Air conditioning and Furnace repair service in Katy, Texas area. When I say "service" I mean it. Every day, including summer holidays, weekends. Repairs also include equipment replacement. I myself install all new equipment I sell. I don't sub out work to sub contractors unless the contract specifies that (which is extremely rare situation). If you don't like the way I do things you're free to look elsewhere. I'm not here to tell you what your ears are aching to hear, I am here to tell you like it is. (Firmly and exponentially based on experience.) You don't have to like what I say, most of the time it's not pleasant due to a variety of reasons. In some aspects similar to the confrontational aspects of this forum boards conversations. Anyone who has viewed my posts know I come thick skinned. Disagreements do not phase me. If you want a gimmick, chase a gimmick. I could not offer the service I offer if my approach didn't work after all these years. I'd be running back around chasing my tail. You'd never get thru when you try to call me. Seriously? Think about it. Chest pounding: If you want to call it that it's your opinion. You're free to have it. My experience is my experience. 26 years. Easily verified. 13 years running my own company. Again easily verified facts. Essentially it's an advertisement. I am not paid to be here. I am here drinking my morning coffee filling in that time. If this isn't advertising my business what purpose would I have to be here? I don't come here to argue with the metamucil fan club that propetuates this board. Ha, ha... you know who you are. People search for me. All I have to do is leave bread crumbs so people can find me. AC repair service Katy, Texas area. Everyday. When I say something I mean it. Not a spam service. Don't sell your info. Don't pester you. You initiate the service you want. It's not that difficult when you know what you're doing. If you want a 20 something or 30 something coming to your home, you have to ask yourself how much experience does this guy really have? If that's what you want go for it. I've worked for companies like that... having to go back behind some newbie over and over and over. Used in not very fun ways. Follow my rules. I've been doing this longer than some of you have been alive. My methods work. Experience. What is it worth? Who else on this board in all the world listed as a pro HVAC service provider has my work ethic? Name one besides me. (beside the mini split warehouse spammer) Truth is stranger than fiction. There are people out there who read these threads and never post due to this kind of argumentative climate so frequent here. How could I know such a thing? I service the Katy, Texas area.