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> BTW, everybody in Arizona has A/C. Amazingly, A/C demand peaks when the sun is high in the sky. Here in California, peak AC demand is late afternoon. Enviro
by mlyle 5y ago
> BTW, everybody in Arizona has A/C. Amazingly, A/C demand peaks when the sun is high in the sky.
Here in California, peak AC demand is late afternoon.
Environmental thermal mass means peak outdoor temperature happens a fair bit after peak insolation. Structures take even more time to heat up and add additional delay. Finally, people arriving home from work means increased AC use, too.
Demand stays fairly high after it gets dark.
(And it's my understanding most other places keep daytime heat later than here).
- WalterBright 5y agoSimple. Set the A/C temp to lower than comfortable during the peak solar times. Your house won't heat up immediately, if you've insulated it properly.
- mlyle 5y agoSure, there all kinds of ways to move demand around from when it would naturally peak based on peoples' preferences. This particular one is only mildly effective; precooling can lower later demand somewhat. My house is very well insulated, but I still cannot coast from 5:30pm to 9:30pm (when windows are sufficient for comfort and demand really starts to slope off) without an excessive amount of prechilling. My structure, insulation, and attic are all preheated by the day's heat and so there is a big warm thermal mass next to my living space. Also, opening windows overnight increases indoor humidity, which in turn requires more air conditioning the next day.
- WalterBright 5y ago> This particular one is only mildly effective If it'll save you 10% on your electric bill, would you do it? I would. And reducing peak demand by 10% can really reduce the cost and need for grid battery storage. Best of all, doing this sort of management of your HVAC system costs you essentially nothing. It's picking money off the ground.