Tiny house ventilation/low CFM fan/ flashing
Hey folks, after reading the ventilation articles here I have a few questions.
Background: 30′ tiny home, new construction, about 225 square feet and 2400 cubic feet volume. All sheathing seams meticulously taped, tyvek completely taped. Located in coastal northern California. Heat source will be a small wood stove with a dedicated air inlet. I will soon install cedar tongue-and-groove siding over a 3/8″ rainscreen.
1. ASHRAE standard (just a reference point) suggests about 10 CFM for my place. Does anyone have a “gut feeling” for whether an exhaust only system would function properly without a dedicated make-up air source here? No blower door test results sadly. The lunos HRV fans look like a great balanced option but may not be cost effective in my relatively mild climate.
2. Does anyone have any recommendations for an exhaust fan that could do low-volume continuous (10 or less CFM) as well as boost enough for the TINY (25 sq ft) bathroom? So far I have only identified the Lunos RA 15-60 as an option.
3. How important is it that I get everything planned and flashed before the siding goes up? Planning to Flexwrap all duct penetrations to the tyvek. If I need to add a 6in duct later, could I cut a larger (say 10 in) hole in the siding, tape the smaller duct penetration, then find a hood that will fit snugly in the larger hole?
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