goti
Thanks for the link to the correct publication.
Sigmetnow
That's one serious T-Stat!
In Las Vegas the power company offered residential customers a discount it they were allowed to install a remote A/C cutoff which would be activated for a maximum of 15 min./hr. when they were at peak demand.
Went into effect about the same time as Jimmy Carter was subsidizing insulation and may still be in effect.
In practice the problem was that peak demand in Las Vegas was also the very hottest days of summer and the A/C units are sized so that they require 100% of capacity at the very time the power company was shutting them down.
Another problem was that they had thousands of A/C units trying to start at exactly the same instant and the resulting momentary brownout caused many units to fail, requiring the very expensive replacement of compressors - again at precisely the hottest times of the year.
A slightly aged heat pump is still a very good solution in most environments, and it sounds as though you've made trade offs that you can live with as far as energy savings and comfort are concerned. Kudos
Bob
Cutting edge technology is where technical problems can occur. In the Yukon study I'd linked to 1/3 had lost their compressor within the first year & 1/2 within 4 years of the installation. Other less catastrophic problems were rampant.
Sealing the home and lots of insulation should be the first steps taken to cut ff usage. Modern gas packs or gas furnaces are marvels of efficiency and all but one brand are actually quite low tech, and therefore not liable to high maintenance/repair bills.
I won't mention the brand by name, but they run a unique glycol system to extract the last BTU and replacing the very poorly located glycol pump is a very costly, recurring problem.
I'm glad to have learned about the new bivalent systems they're presently testing, but I'd give them a decade after sales are initiated to work the bugs out. They could solve the defrost problem inherent in heat pump design, but tweaking them to work at various temperatures, loads, and humidity levels is going to take some time.
In my California house with high humidity (until the last few seasons), and moderate temperatures, I've rigged the heat pump to cut out at 40 F when the rather aged gas pack takes over. As an absentee landlord this saves on compressor wear, condensate water problems, and provides the tenant with the most reliable heat available at very reasonable energy costs.
If I was living there myself I'd probably experiment by using, (and heating) the swimming pool during the cooling season and tweaking the heat pump to run until at least the first defrost cycle below 40 F. I'd expect noticeable energy savings, especially during the lengthening cooling season, a toasty pool, and lots to tinker with during the year.
Terry