I don’t think this is intended to be used in isolation. Cooling dry air is much less energy intensive than cooling dry air + a bunch of water. So, this device efficiently removes the moisture from the air, allowing the ac system to do less work.
I was thinking a smarter thermostat should be able to monitor humidity in the air and run the AC at a low level, ramping up as moisture goes down, but that doesn't seem to be a feature in any of them (product idea?).
Maybe a separate dehumidifier like the one in the article combined with an oversized system could work?
In Arizona 117 is common enough that you’d expect the AC to handle it with no problem but Texas it probably isn’t that common (guessing). Think the hottest it got since I’ve lived there was 122. People also commonly don’t cool their houses too low because it gets expensive, my sister used to have a McMansion and their AC bill was a lot (something like $400/month) and they were only cooling to around 78 or so.
Commercial spaces have giant units that cool much more than I want. What are they doing differently?
Wouldn't a "right sized" system plus dehumidifier be better? If you oversize the AC to the point it short cycles, it won't be providing as much dehum as you have now, so you'd just be shifting that load to the dehum, not helping overall.
One exception is Carrier’s Infinity system, which is variable speed. It’s relatively more expensive, still not all that expensive, and may be overkill if you don’t have multiple zones, which it can also handle. Also, you’re stuck with Carrier’s matching thermostats. But it may be a good choice if you’re looking for flexibility.
Any reason why? I would naively think that putting in a variable speed motor with a dial would be peanuts on the total cost?
Or just get a variable-speed heat pump to handle cooling and heating.
Most HVAC companies like to have a "standard" line they do and then charge dearly to deviate from that, because that's where callbacks and problems come from.
On the other hand, I'm asking them to sell me something that's more expensive and the fact that they don't want to tells me that they have some reason to believe I wouldn't be happy with the result.
The max 25 drop does seem to be a widely reported thing. For example, my first search result for "max ac drop" is this:
https://www.jerrykelly.com/blog/how-many-degrees-cooler-can-...
The temperature rises and the AC kicks on. The plenum chamber in the AC unit, which is near the roof and is hot is flushed out to the condo interior. So we get a blast of hot dry air, followed by a blast of cold dry air for a brief period. The large unit quickly cools the condo and then switches off. So on a hot day the unit is cycling all day. This still happens on the hottest days of summer [in contrast, perfect would be a unit that, in the hottest weather, turns on and runs all day, barely keeping up]. To boot, this raises the electrical bill and stresses the AC unit.
So don't get a unit that is too big. Go to the trouble to have the unit sized properly.
The dehumidifier sounds great but it will decrease reliability and be one more thing to fail. It might be worth trying. Definitely don't use it with an oversized system - use it with an undersized system!