Why it matters to you
Houston (IAH) logs about 3,288 cooling degree days against 1,266 heating degree days a year, so the thermostat's cooling schedule and fan setting shape comfort and run time most of the year. Leaving the fan on 'On' instead of 'Auto' can blow moisture from a wet coil back into the house.
Practical guidance
Homeowners can replace batteries, set schedules and keep the thermostat away from sun, lamps and supply vents. Before buying a smart thermostat, confirm it is compatible with your system, especially heat pump, multi-stage or communicating equipment; wiring changes at the equipment are technician work.