Layout for ducted minisplit?
My house’s floor plan has too many partitions to depend on comfortable heat distribution with ductless so I’ll take the slight efficiency hit to use duct ed distribution. The plan is to keep the ducts inside the “conditioned” envelope and very simple and all in the ceiling service cavity, both supply and return for the air handlers. My house is a rectangle with the long side running east to west. A central hallway divides the north and south areas. My proposed layout uses two air handlers, two zones, one “bedroom” zone on the east and a “daytime” zone on the west. Both air handlers are located in a “dropped ceiling” over the hallway and get return air through a grill at the east end and supply air goes to a “trunk” , also located in the dropped ceiling, flowing toward west. The air handlers and supply trunk ducts are mounted to the framing that supports the ceiling drywall. Supply branches, serve individual rooms though ceiling mounted” registers and run either from north to south or south to north . The top of the trunk ducts is the bottom of the branches and the top of the drywall. The trunk ducts are 6″x24″, the branches are 3″x14″ (could be 3″ x 20″). I plan 4 branches from each air handler. The ERV has independent inlet ducts and returns it’s processed air to the return air “box” of the east air handler. A 20″x20″x1″ disposable filter will be above each return air grill. All rooms that have supply ducts will have “jump ducts” for return air over their doors. I’m wondering, should I locate the supply register(s) closer to or further from the supply? Further, i think, results in more even temperature but clearly results in more pressure loss. My air handlers are capable of 0.4″wc @ 360CFM and can be “dialed back” to accommodate lower back pressure duct systems. I believe there is no need to add balancing dampers and there by additional losses. Will I be disappointed?
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