The Santa Fe Advance is a powerful dehu and able to handle 3,500 sqft. of space Get a duct kit for the SF A. The intake comes with a 6" and 10" return. Have your a/c tech bring a 6" fresh air duct in through the rim joist to the 6" return. Connect the 10" return to a duct from the main floor.
Originally Posted by backpacker
On the supply side, attach a 10" Tee with a damper on the side of the tee open to the crawlspace. Connect a 10" supply duct to the mainfloor. Use insulated flex duct for all of the ducts.
Partially open the supply to the crawlspace enough to keep the crawlspace 50%RH. Open the 6" fresh air enough to introduce 70-80 cfm of fresh air to the dehumidifier. The fan on the dehu can operate 24/7 to provide circulation and fresh air throughout the space.
Keep us post on your results.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"