ERV for Studio Apartment
Trying to finalize decision on mechanical ventilation for ~600 SF 2d story apartment in the detached accessory dwelling unit I’m completing (North Idaho, Zone 5).
Originally, I planned an exhaust-only system, using a Panasonic WhisperGreen fan located in the bathroom, with motion sensor and timer.
Based on the results of initial blower door testing, I expect the living spaces in the building , which also includes 300 SF office + bathroom on the first floor, to come in at 1 ACH50 or less. That has me thinking exhaust-only may not be an effective solution, at least not for the apartment. Looking at balanced systems, I’m considering a Panasonic WhisperComfort ERV with Panasonic’s FV-WC04VE1 Wall Cap with Styrofoam adaptor so I can use a single wall penetration for both intake and exhaust. Or, something like the Panasonic Select Cycler paired with WhisperGreen Bath fan https://www.greenbuildingadvisor.com/article/pros-and-cons-of-three-types-of-ventilation-systems
Questions: If I go with the ERV, will I still need separate bath fans? At 0.8 Sone and 40 cfm, it seems the ERV is louder and moves less air than the WhisperGreen bath fan, and is designed for continuous operation. Is the energy savings from the ERV worth it vs. a bath fan plus Select Cycler? (For reference, the ADU is heated with 2-1000 watt baseboard heaters controlled by programable thermostats, and designed for net zero or better, with PV to be installed this fall or next spring).
I’ve attached floor plans below which should things a bit more clear, as well as photos looking east and west of the second floor apartment interior, showing framed-in bathroom with mechanical space above.
Thanks in advance for any advice.
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