No numbers on potential efficiency gains.

This also seems like a likely capital cost vs operational expenses optimization. What is the upfront cost premium for the dehumidifier vs lifetime energy savings?

I’m all for efficiency.

How much energy is used on AC?

How much would a 10% improvement in efficiency save?

This is anecdotal of course, but for me cooling with AC is easily over half of energy bills I get.

Better payback in terms of efficiency and resource use to just properly insulate buildings, seal up ducts, etc.

Better ventilation and effective greenery also help a lot. Green areas are easily a few degrees cooler than asphalt jungles. Use smaller roads, replace lawns with large trees and allow windows to stay open.

Floors near the ground level benefit from the plants. And it is a lot colder at higher floors anyway.

The problem is poorly-designed housing. Go semi-subterranean with heat pumps for unusual weather. Example: https://youtu.be/RoGuvvzHY1A

I wonder how that would fare in our climate in finland, where the ground freezes and thaws all the time, breaking just about everything we lay in it, including roads, signs, pipes, foundations...

Another issue in Finland is that the average soil temperature (like, a few meters down) is only five or six degrees. But that leave a lot of room for a heating upgrade...

IMHO if you can capture the massive surplus of sunlight in summer and use it in the winter, it would be a major win. Some way to set up a big underground heat reservoir ?

5~6 CELSIUS degrees. Low 40s, Fahrenheit.

Rebuilding all houses will take perhaps a century. It might be easier and cheaper to add insulation to existing houses, such as using spray cork:

https://buyspraycork.com/

https://thermalcorksolutions.com/spray-cork-the-perfect-non-...

This article seems to be mainly about larger air conditioning systems, whole house units or industrial ones, which is great, higher efficiency would be useful there. I'd also like to see some improvements in low cost window air conditioners. The only brand I know of that has tried to improve efficiency is Midea which sells inverter based air conditioners. It would be nice if they added a HEPA air filter, a heat exchanger to bring in fresh air with little energy loss, and if they kept mold out instead of encouraging it. We know air quality has a big impact on life and filtered air can reduce airborne diseases and reduce mold, allergens, and the need to dust off everything periodically. There has been little change in window air conditioners for decades, seems like an area that is ripe for disruption, and with efficiency improvements they would help reduce load on the grid and cost less to run. Also there is no reason a window unit can not be a heat pump and do efficient heating as well as cooling.