Thanks for this ping. This unit could be used in our kitchen at the window over the sink to exhaust hot/stale air or to bring in fresh air from the outside.
Once you have a 12 V storage battery capability take a look at USB lights and fans. In the past year or so there have been significant LED driver advances and more efficient small DC motors.
Here’s a link to one of their fans I’ve used for more than a year...OPolar USB dual desk fan
Has a small foot print, easily stores, dual stack fans tilt and oscillate multi speed, very quiet w/10,000 mAh lithium batteries. Fit my sliding glass windows for exhaust and fresh air intake...all night long with power to spare...can operate on direct DC from wall adapter. They also have Great way to stretch available battery capacity.
Another big advantage is that with onboard rechargeable batteries the fans and light aren’t tethered to inverter outlets or extension cords...move them as needed. USB 5V items are cheap and efficient now...even RV owners are moving away from 12 Volt small appliances. Get a high USB 3 12 volt adapter plug and some power banks for distributed wirpower.hortable power.
If it is really quiet, it could be used in our family room or master bedroom to move the air around.
Doesn’t bother my sleep running all night...and my hearing is still excellent at mid 70 years age.