Growing up in San Jose, my dad ran a very profitable business and was also miserly about home climate control (it's the single biggest energy expense, after all

Growing up in San Jose, my dad ran a very profitable business and was also miserly about home climate control (it's the single biggest energy expense, after all). A/C was limited to a single in-wall unit that was only to be used when outside shade temperature reached 95 F / 35 C. If you wanted to cool down, it was a fan or go for a swim. Heat was whole-house, natural gas with floor registers, set to inside 65 F / 18 C max. House had both fiberglass and blown insulation, automatic ridge-line roof venting, tall tree shade, multi-pane windows, weatherstripping, room isolation manual practices (door and register closing), etc. This was in the 1980's-1990's before "green" was standard practice, it was self-interested to save TCO money.