Can a multi-head minisplit be electrically separated to two different electrical meters?
I’m wondering if single outdoor mini-split units, that operate two or more interior wall units, can have the electrical demands of the interior units metered separately?
I have spec’d a MUZ/MSZ-FH12NA Mitsubishi H2i Hyper Heat Pump for an apartment above a garage, and was trying to avoid installing two outdoor units, when I can buy one outdoor unit that would heat both the apartment and the garage/workshop and bathroom below. The apartment is on it’s own electrical panel, but shares the same electrical meter. I’m using a wattstopper like device to monitor the apartment’s electrical use (for billing purposes), that way we don’t incur an additional $30+ charge a month from our utility just to have a separate meter.
I’ve attached a plan that shows the wall makeup of the garage/workshop/bathroom, and includes window, door, and garage door R-values, and sizes ( for heat loss calcs). I’m pretty certain I can go with a FH09NA mini-split for the garage, but that means having two outdoor units, which increases my costs quite a bit – about $2500 more than going with radiant ceiling panels – obviously the mini-splits are more efficient. I also have lots of PV, because I’m hoping to have a zero-energy property.
The other concern I have is that the apartment (which are totally isolated from the lower garage), has it’s own entrance (with small vestibule), which provides a small mudroom type area for the NH winters we have. The apartment stairwell, which is accessed via the vestibule is open all the way up to the apartment. The apartment has exposed rafters and barn board, so it is a cavernous space. Should I assume that since the vestibule is just a entry vestibule, that the passive heat it collects from the mini-split above in the apartment will be sufficient? Do you think I should add electrical resistance heat there? OR should I figure out a way to isolate the vestibule at the stairwell (like an airlock persey?
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