There are three main types of thermostats on the market today — manual, programmable, and smart models. Manual thermostats have a number of drawbacks, mainly in their limited accuracy and inability to adjust to temperature changes automatically. That leaves programmable and smart thermostats. If you already have a programmable thermostat, is it worth is to switch out to smart programming? Before you call HVAC services in Atlanta to do a new install, here’s what you need to know when comparing programmable and smart thermostats.