Smart or Wi-Fi thermostats are all the buzz these days, but some of it is just a matter of smart programming. Here’s what a smart thermostat can really offer you, and how to decide whether or not you really need one.

Regular thermostats let you adjust the temperature in your home—it’s just a control panel for your heating and air conditioning system. Programmable thermostats let you set the temperature and have the thermostat change it based on the time of day. What makes most smart thermostats, so “smart” is that they learn from your behaviors, allow you to control the climate in your home remotely, show you energy consumption in real-time, and can even adjust themselves based on ambient conditions like humidity.

For example, you can tell your Wi-Fi thermostat to shut off after you leave your house for work, and then spring back into action in just enough time to make the house nice and cool and comfortable, by the time you get home. Most Wi-Fi thermostats show you how long it takes to make the change you’ve requested, so you can see how effective your climate control system really is, and it discourages people from turning a thermostat all the way down to try “cooling off the house faster” (which never works). Plus, you can manage many Wi-Fi thermostats from your phone or a web app. From the remote interface, you can always see how much you’re spending on heating or cooling costs, tweak the programming to you save money and see the results immediately.

Wi-Fi thermostats usually come in two varieties: The type that learn automatically from your behavior and adjust themselves accordingly (and therefore don’t even need you to program them), and the type that offer internet connectivity for remote management and programming. The best models fall into both groups.

The catch is that smart thermostats tend to be expensive. Almost any smart thermostat will require more money at the outset than a simple programmable model, so factor in the time and/or the cost required to have it installed when you consider the cost.

Whether or not a Wi-Fi thermostat will actually save you money depends on a few factors. You have to consider how long it’ll take for the initial investment to pay for itself, how long you plan to stay where you live, and whether you really need all the bells and whistles. Only install a smart thermostat if you’re sticking around for a while, or plan to take it with you to your next home. Of course, if you’re the type who loves data and loves tweaking systems to improve them, a smart Wi-Fi thermostat will definitely save you money on your energy bill. Then you can always check your thermostat’s mobile app to see how much money you’re saving or energy you’re actively using!