What to Set Your Thermostat to During a Heat Wave According to energy experts and the U.S. Department of Energy, the sweet spot is 78°F (26°C) when you’re home and need cooling.

For the smart thermostat I have (an ecobee3), the answer is no. It does support two stage heating and cooling systems, but only a single zone. I think the Nest is the same. I have cheap Honeywell ...