Jennifer, I am a licensed HVAC technician in MA and an engineer for over 30 years. In stumbling upon your post I joined to urge you to please stop and reconsider what you are doing Monday. There are many ways to provide A/C for a house and the best way to start is to do a heat load for your house. If that has not been done you are being ripped off. The question of vents and dust and moulding can easily be answered with a unit from http://www.unicosystem.com/ These people and a couple of similar companies units are made for this condition and will answer all your questions. Delay the work and call the company directly. Simply put they made for historic restoration jobs, the move less air so smaller vents or different types usually hidden, less air means less dust blown around. Yes they are just as quiet or more when installed correctly and you will be happier! Cost is comparable and if you have not been given this option you need to question if the contractor is the right one for you, he should have offered this to address your particular concerns.

Most central A/C (and forced air heat for that matter) draw internal air, cool (or heatt) it, and the blow it out into the living space. Some window units have an option to mix a little outside air into the room. Usually there's just a button or knob to turn it on or off as desired. The unit is more efficient when it is not drawing air from outside. The filtering on window units is minimal.

If you were me, you would run away from Trane hi efficiency heat pumps. I have had the new unit, air handler, new lines for almost 3 years. The installer is certified by Trane and the unit has a 10 year extended warranty. When it was sold to me I was told everything is covered. I now have a 850 dollar bill on my hands because Trane refuses to pay the installer for work that had to be done on the unit last month. They have worked on the unit 5 times in 3 years. I can email you the documents that show that Trane will not back up the warranty, if you send me your email. By the way the unit does not currently work and I am not sure who to call, other than my attorney. Trane seems to not care when issues are pointed out. They go on selling the units like hot cakes and ignore those such as myself that have units that do NOT work. eddie_brown@yahoo.com

ok..thanks.. what is the condensate kit? and are there any other brands that stand out in the field?