We just had a Carrier Infinity 80 system with a Performance 15 seer a/c unit and the infinity control installed, along with an american standard accuclean unit. Unit is upflow, accuclean on the bottom, furnace over it, bit of sheet metal over that to connect to the three supply lines.
I have a couple of concerns that hopefully someone here can shed a little light on.
When they installed the accuclean/furnace stack, it seemed that the accuclean box was sagging a little in the middle. The furnace is narrower than the accuclean, and sits somewhat to the right of center on the accuclean cabinet. When the installer went to put in the filters, they wouldnt fit. He pulled up on the middle of the cabinet and that seemed to straighten it out, filters went in, filter came on and worked fine. I had the feeling from listening to the two guys talking to each other that neither one had installed one of these before.
After they were done with day #2, which was adding the a/c and installing the thermostat, the accuclean now comes on but doesnt ever "engage"...the LED light stays on but doesnt blink. I'm guessing they didnt properly connect the wire that tells it that the fan is on.
In checking it out, it was a little hard to get the front door off the accuclean and to get it back on. Had to force it a little, and I see that the cabinet is again a little bit compressed, sagging in the middle a little bit.
I'm concerned that long term this is going to be a problem. The installation guide mentions supporting the rig from the upper sheet metal, but they built this bottom up and I dont think its attached to the wall or ceiling except to join the top of the coil to the supply lines.
Duct-wise, I failed. After they replaced a lot of ducts and SAID they did all the sealing in the crawl space and attic, I was getting a 30-32% loss. They said it had something to do with some supply lines to the kitchen and bath coming up into the cabinets ("they just cut a hole in the floor and fed the line into the cabinet and then put a grate on the front"). I can see what happened there, but I'm surprised its a 30% loss in the system from two cabinets. In pulling up some floor registers, I can see that theres about a half inch to three quarter inch gap between the edge of the sheet metal and the floor cutout. Its not filled or sealed. We've got 14 of those. Its a 20 year old 3 story, and theres plenty of supply/return ducting running through the interior walls where its inaccessible.
A/C wise, the new Carrier Performance unit is huge compared to the old Payne 9 seer we replaced. The old unit was on a small slab that was starting to sink a little and left it a few inches below grade. The saleman mentioned "pouring a new slab over the old one to bring it up a few inches". The installers had a large plastic platform that weighed about 10-12lbs that they laid over the top of the old slab, and placed the unit on that. The plastic "slab" isnt attached to anything, and the a/c unit isnt attached to the platform. They also put the unit about 7" away from the side of the house, and I know you guys love that, but not a lot of choice since the ground slopes away from the house once you go past the edge of the old concrete slab.
Any info on how this SHOULD be done to have it be proper and work better for the long haul is much appreciated.