First post here. I appreciate all the great info.
Just bought a house and once moved in instantly had allergy issues. The AC was shot anyway so we replaced it with a new Trane unit. Despite this we are still having issues with high humidity peaking at almost 70 and down to 55 or so when the unit has been running. We are looking at adding a whole house dehumidifier with outside air ventallation. The question is what configuration to install it in. The first option pulls air from the return duct, mixes with outside air, filters and returns it to the return duct before entering the ac unit. I like this option because it will go thru the main units filter. My problem is that I dont know if it is a good idea to blow air over the coils when the AC unit is not cooling and redistribute the moisture off the coils back into the house. The second option is to pull out of the return and bypass the AC unit and feed air back into the supply duct. The problem with this option is I do not get the pass thru the AC filter and only the dehumifiers filter would filter the outside air mixed with the return air. Additionally I would need to add a damper on the supply so that when the ac was running it does not backfeed air thru the dehumidifier supply side . Can someone advise which option is better? The unit we are looking at is the true dry DR90 thanks in advance for any feed back.