Hot answers tagged temperature
Simply exchanging the air between the rooms will equalize the temperatures because the air will mix. I would just cut two vents in the wall, one high and one low. Natural airflow probably won't be enough to balance the temperature, so put a fan in one or both of the vents. If you do both, point the fans in opposite directions. Again, it doesn't really ...
I am not aware of any professional products for this, but you could get an arduino or rasberry pi device with two temperature sensors, and hook it up to a bi-directional fan and write some code to have it automatically start at a certain temperature difference.
Here's a dead-simple idea: use a PTAC unit to air condition the room with excess heat, and dump it into the adjacent room. That's the general idea behind how companies with huge server rooms recycle heat during wintertime. Their systems are much more sophisticated, of course, inevitably involving heat exchangers, water cooling, thermostats, multiple zones ...
I would recommend first contacting a home energy efficiency company first rather than an HVAC company. HVAC guys are usually clueless about systemic problems like these and will usually try to sell you a larger unit without diagnosing the true cause of the issue (which is a pain in the neck and can probably be fixed for much less than the cost of new ...
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