I have a 100 yr old, 1200 sq ft house in Houston. I have no insulation in the walls, 10' ceilings, and every room has several original 3' x 6' and 4' x 6' windows on each wall. I have fully insulated the attic, added a radiant barrier to the underside of the roof, and sealed the windows as I best I can.
I currently have a relatively new Trane XB80 furnace and an ancient 3-ton Janitrol A/C condenser. The ductwork in the house is mess - a sloppy job from the late 80s, I would guess. I have improved improved it somewhat by adding a second return box and trying to seal the ductwork up better.
However, as you might expect, I have a big problem with humidity in the summer, given that I live in a not-very-tight old house in Houston. I run a large portable dehumidifer and have to empty it twice a day in the summer
I plan to now have the condenser, coil and all ductwork replaced, but due to budget would like to keep the existing furnace.
With the existing furnace, what is my best alternative for improving humidity control? One installer told me that, with a new condenser and ductwork, just changing the speed setting on the air handler fan would probably fix my problem. (It is currently at max).
Is there an "intelligent" condenser/controller system (of any brand) that would work with the existing furnace/air handler? What I would like to do is have a system that would be able to keep the house in the summer at 78 F and 40% rh.
Any advice would be most appreciated. I've gotten bids from 3 guys so far (all 3 ton units - 2 Carrier Comfort, 1 Ruud UAPL-JAZ), and none of them really wants to provide me any logical explanation of how I can do a better job of effectively controlling humidity in the house.