An efficient HVAC system keeps your home comfortable and saves you money. The first and most important way to increase the efficiency of your system is to regularly clean and replace your filters. You'll also want to schedule routine maintenance and tune-ups for your entire system including ductwork. Programmable thermostats greatly decrease the load on your system which saves money on bills as well as wear and tear on your system. Finally, although it's a big up front investment, considering a system upgrade will pay off in the long run.