If you are trying to upgrade your heating & A/C equipment with a current smart thermostat, you can often get a rebate to help with the cost involved. I know the utility corporation feels that even if a little bit of savings occurs while you use your heating or A/C, then changing out the thermostat is well worth it. Some smart thermostats come equipped with sensors, giving it the ability to measure the temperature settings & monitor the climate control of basically any room, & not just the area where the thermostat is located. A smart thermostat will enable you to make changes to your temperature settings while you are not at your home, allowing the thermostat owner to make schedules as to when the A/C will turn on, or the heating unit, etc., but the smart thermostats with sensors are getting popular. However, keep in mind, that it is not exactly a straight-forward job to swap out the aged thermostat for a new, smart thermostat. There is plenty of work involved in doing so, & I recommend taking a picture of the inner workings of the aged thermostat, after the aged cover is removed. You will also discover youtube videos online about your particular, chosen smart thermostat, so watch it to prepare better because you will be investing quite a bit of time & currency into any thermostat you happen to get. So do your smart research & head on down to the local hardware store, but keep that receipt for the rebate so you can get a little bit of currency back on your current smart thermostat!