The HVAC system for a house, or any other structure for that matter, is both complex and simple depending on how you look at it. There is always an air handler located somewhere in the place, and one of the most crucial parts of the HVAC plan is what is called the thermostat. This is essentially the core of the HVAC system, as controlling the temperature of the house would be much harder without it! Thermostats used to have a mercury bulb on the inside, but that technology is obsolete. In today’s more advanced world, the mercury bulb on the thermostat is replaced with digital thermostats that do the thinking for us. The thermostat comes in many weird shapes and sizes, with plenty of customization options to choose from. The cooling system thermostat can be programmed to turn the cooling system on or off at random times, too. This saves you energy, and cuts cost in the long run! With the outdated thermostats, you could not program them to do your bidding like today’s thermostats can. They were all manual, with no digital qualities about them. HVAC systems as well as thermostats have been evolving into super thinking machines, and the most modern thermostat doesn’t even need the human anymore other than to initially program a schedule or change a battery. Controlling an HVAC system remotely is possible thanks to special applications. Now, having a smartphone and the associated app for your thermostat means you can make the house cooler or hotter just using your phone. You couldn’t do that 20 years ago!