[daepp]

Thanks Cab - good info!

Originally Posted by billybek

That ducting I can see in the photo looks to be mostly flex ducting. I can't even imagine the loss of flow due to resistance from this type of ductwork. Plus the fact that they look like they have been flattened and that significantly reduces the flow area and increases resistance to air movement. Good eye sir. Pretty much all of what I've seen beyond the units themselves is old, abused and flexible.
If possible, I would have them re run the mains (supply and return) in hard duct that is seam taped ad insulated. Accessible zoned dampering at the trunk or diffuser or both would be a good thing. I've now gotten this advice too many times to ignore!
The advice of going to a zoned system varying the airflow based on temperature is a good one but may be expensive.
The solar panel install on the sunny side of the roof with an air space under them will reduce the heat load on the upper floors and ceiling space. I'm sure hoping that will be the case!
I would not be afraid to look into mini splits that could handle a difficult zone to service from the existing mechanical area. Can one of my (new) compressors handle both the main unit and a mini-split, or do mini-splits have to have their own compressors?
I was looking at one the other day that the indoor coil looked like a painting frame that the home owner could change to suit the decor. What a great idea - we recently purchased a television that does much the same thing. We didn't want a TV to be the main focus of room, and now visitors think it's a painting.