Update: The repair guy just left and here is what he found. The upstairs unit's air flow was low and he fixed that by chaning the 12 inch line with a 16 inch line. Still not sure if that was better choice than putting another air return, but he says it has about 800 cfms now which is suitable for a 2 ton unit. It turns out that my downstairs unitl had too high of an air flow with about 1500 cfms for a 2.5 ton system. He "repaired" that by putting a piece of sheet metal in the basement return to reduce it's air intake. The heat seems to be hotter coming out of the vents now, but some of the vents have very low air flow. Damned if I do, damned if I don't situation. After he got the air flow "corrected" he finished checking the system and found that both heat pumps are still freezing up at the compressors and they are building up way too much pressure. He thinks that both of the coolant lines have blockages or are restricted. If these blockages are not fixed he says the cooling/heating compacity of both systems will remain greatly diminished and that the one compressor will probably fail within a year due to the constant overpressure. Anyone else have any experiance with this? How about home warrenties, do they typically cover situations like this? Thanks

They're selling snake oil. There are so manys thing wrong with this proposal. First off, why do you feel you're not getting enough airflow? Is the room they used for their demo hard to heat or cool? If the existing 370 cfm is enough to keep that room comfortable, then there is no reason to pay money to increase the airflow. "More" is not always better. Your air handling system was designed to move air as an enclosed system. OF COURSE it's gonna move more air if you rig it to operate with the fan cover door opened. But again, more is not always better. I'll bet you could stand in that back room and *hear* the air rushing and whistling out of that vent after they took the blower door off. Your system should be set up to move the required amount of air as quietly as possible. You're also risking damage to the blower by making such a drastic change to the static pressure. The fan is designed to work against some amount of resistance. Lessen or remove that resistance and you could burn your fan motor out. A return in the basement is going to bring extra humidty and musty odors into your home. The air conditioning unit would have to work harder to remove the extra humidity. It could actually cost *more* money to operate. And if the unit was not capable of removing the extra humidity, you end up with damp air in your living quarters. This results in a cold, clammy feel that makes you feel uncomfortable. If you have some rooms that are hard to heat or cool, have a reputable HVAC company *calculate* how much air needs to go to each room. It's not a guessing game, and more is not always better. I noticed that you called the original installers and they blew you off. Forget them, they don't sound very professional. Try asking some of your neighbors for referrals, or check something like "craig's list". There has to be a reputable company in your area.

1.put an upflow airhandler on a platform on one end of the bldg. put condenser just outside of it, put a plenum on the supply with sidewall supply grilles blowing into the main building and run a round duct (probably 5 inch) over to a ceiling diffuser (8x4x5 or 6x6x5) in the bathroom. OR 2. hang a horizontal air handler with plenum on the supply with sidewall supply grilles on it and run a round duct to a ceiling diffuser in the bathroom. OR 3. put a bard type wall unit at one end of the building but instead of just putting the one grille on the supply, run a rectangular supply trunk duct down the center of the building with sidewall grilles on it and run a round duct to a ceiling diffuser in the bathroom. I dont charge a design fee over the internet :) good luck with your project.

I have HEPA air filters in multiple rooms of my house but it is still very dusty. I thought it was because the windows were open earlier in the year, because this is a dusty environment (Sierra Nevada mountains) but the windows have been closed for a month. There isn't forced air here, so it isn't the ducts. I vacuumed an entire bag's worth of dirt out of the carpets the first two months I lived here with a brand new Miele vacuum. I fixed the dryer vent which leaked. The dust still appears overnight! Help! I like the idea of a filter before the box fan although I am going to have to come up with something more attractive than duct tape to make that work in my bedroom!