>Strangely, I saw more units with central A/C in Toronto than in San Francisco. I guess they're used to hot summers there. A home in San Francisco doesn't need

>Strangely, I saw more units with central A/C in Toronto than in San Francisco. I guess they're used to hot summers there. A home in San Francisco doesn't need central heating at all, but a home in Toronto (where it remains frozen for a few months in the year) very much does. Once you have central heating, adding a central A/C unit (or a heat pump) is not a significant additional expense compared to how much a home usually costs, and failing that can be roughed in for later installation, so the decision to purchase one when the summers get too hot is an easy one, or when you have a family and want A/C so that small children or the elderly don't roast while living/visiting.