New House, HVAC Nightmare

[nailbird]

Greetings all,

Just moved into a 1998-built home amidst the extreme heat here in Maryland. It was quickly obvious that something was amiss with the HVAC. I quickly found multiple problems.

The house is 2 stories with a basement - three levels and around 2400SF with lots of vaulted spaces on the floors 1 and 2. Given the extreme heat the 2nd floor was unlivable. The prior owners converted to dual heat (natural gas) and installed a new Rheem system.

The HVAC systems was running flat out. The basement was as cold as a meat locker, the 1st floor was getting some cooling, and the 2nd floor almost no flow at all. I started my investigation.

I could find no dampers in the house. A central chase (around 3'x3') runs from the basement where the air handler is located to the attic and serves as the return air duct for the house - inside the chase is a distribution duct that routes treated air to the attic for distribution to 2nd floor ceiling vents. The air handler is rated at 4.5 tons, but the outdoor heat pump is a 2.5 ton unit (hmmmmm). I opened the attic access panel and recorded over 135 degrees - despite being well insulated (batting) the ceiling drywall in the 2nd floor was hot to the touch. There are good-sized attic vents (about 2.5 ft in diameter) at both ends of the attic, but no air movement. I found water stains in the basement ceiling drywall and opened up a hole to find a lot of dripping condensation. The Rheem air handler sounds like a wind tunnel, the noisiest unit I've ever heard. There are no return air ducts in the basement. There is one return air duct on the first floor, and two on the 2nd floor.

After speaking to a few neighbors I discovered that several had upgraded their systems. The trend seems to be installing centrally controlled dampers, and a sophisticated thermostat that can sense temps on all three levels and direct air where it's needed.

I'm not familiar with Rheem systems, but not impressed with what I'm finding. I used Trane and Carrier systems on prior homes which were far quieter. I have a feeling I'm about to open my wallet wide to fix multiple problems.

I could sure use some expert advice as my head is spinning on this one!