Thanks tk03. I understand what you and udarrell are saying. I have a call into a window joint to see if I can get storm windows on my house soon. At the same time, I do need to act on a new system soon, too. So, let's say I get the house fairly sealed up with storms, maybe new weather stripping around the doors if needed. Then, from my OP, which system set up would be optimal for 2700-2800 sq. ft. home with 17 registers (+ 5 more in basement) and which of the dealers has done an adequate job of sizing my needs? Here's what my Trane rep had to say about my questions: "The static air pressure test is not required. Balancing of the dampers can make a nice improvement, without the static air pressure test. The exposed ductwork in the basement can be sealed with foil tape or duct sealer (caulk type or 1 gallon can). Home Depot has those items so you can do on your own if you like. The cost for us to do the duct sealing would range from $250.00 to $500.00 depending how much time it would take. The air infiltration for your home is most likely average, the equipment that I recommended will do the job well. The duct sizes within the walls cannot be modified to increase airflow very easily. The existing ducts that are in your house are typical for the homes in the area. The variable speed furnace will react to the duct work and adjust airflow. How? Electronically it monitors the RPM of the motor and checks the amp rating and speed settings. If it is not moving fast enough the power level is increased to the motor and the speed is increased. The current furnace cannot respond to the ductwork like the XV95. The TRANE XV95 can move up to 40% more air." My response: "I'm just concerned that if I were to make home improvements after purchase (buy replacement windows) that the furnace and/or AC would be oversized for my needs due to higher efficiency, less heat gain/loss from the replacement windows. At the sizes you recommended, would I be in danger of the AC satisfying the thermostat too quickly or not removing the proper amount of humidity if I were to tighten up the house with new windows, thus still leaving me with warm/cool spots in my house?" Again, thanks for your help! - Angrysalad

ekeg first you need a load calculation for both heating and cooling. get it in writing. review it carefully. on the AmStd quote, you need the model numbers to determine the size the dealer is quoting for both furnace and AC condenser. i personally think a two stage AC for a townhouse is overkill and not necessary. 72 KBTUs sounds way too large. and big is not better. and if you have reasonable electric rates, you could consider dual fuel, furnace with heat pump condenser. IMO TD

The availability of parts has been the biggest compliant about Lennox even before the problem caused by Covid. All manufacturers have this problem to various degrees. It depends on what part it is --- and when you need it. Supply houses get charged tax on inventory they store. So there's much more to this than just blaming a "particular brand" IE brand bashing. Certainly I've experienced the Lennox part problem before, but I've had issues with Amana as well and they are manufactured locally to me. Had problems with Carrier / Bryant -- & American Standard. There is no perfect brand, don't kid yourself. What does a "lengthy" HVAC career tell you? You have to actually do the work to know. (OR listen to me... but many on this board have a "problem" doing that. LOL) For the record, I wasn't blaming Covid... There's another "C" to blame. (final jeopardy, ha~ha) I service the Katy, Texas area.

My Texas house had two Trane furnace/AC units in the attic, and they were suspended from the roof rafters with metal strapping. The drain/condensate pan was then suspended under the A/C unit. This was a very common installation in that area. The units were not connected to the ceiling joists in the room below and did not touch them, so there was no direct transmission of vibration. You could tell the unit above the bedroom was running, but that was because you could hear the air flow into and out of the room (each bedroom had an air return). Bruce