Humid - Switched Trane xl1200 AC for a Payne HP - now very Humid
First of all, you don't have a humidifier on the furnace that is running in cooling mode, do you? Make sure it is not running, for some reason. Not likely the culprit, but anyway....
Dehumidification is achieved in residential systems based on how long the AC unit runs. The longer the unit runs, the more it is "drying out" the air. If the new system is getting your house cool enough (which it sounds like it is), then the problem is likely that you are cooling too well, and too quickly - meaning that the unit cycles on, quickly gets the thermostat to the set temperature, and turns off, without running long enough to "wring out" the moisture in the house. This is commonly the problem when an AC system is oversized for the building load - cooling is achieved too quickly and not enough dehumidification occurs.
Have you made any recent changes to your house that made it more AC efficient - such as getting new, insulated windows, adding insulation to an attic, etc.? It is possible that your system is oversized for your house, and the old AC unit was running so poorly/inefficiently that it sorta "balanced out" and was doing enough dehumidification, because it had to run longer to cool the space. Now you have a new, more efficient unit, and it gets the space cool so quickly that it is not drying the space out.
Of course, it could be the opposite - do you live in a humid climate, and recently did some work that would be letting more moisture get in to your house?
Try timing your AC cycle and see how long the unit runs before turning off. Do you have any idea how long it ran with the old unit?
Upon re-reading your post, if there is not enough air blowing period, make sure your cooling coil is clean, and that nothing is blocking the air passage through the unit.
Last edited by pjpjpjpj; 06-11-2007 at 01:18 PM.