One of the largest expenses associated with running a household is keeping the inside temperature comfortable. One way to control these costs is with a higher efficiency HVAC system. Designing Spaces Think Green visits Tallahassee, Fla. to visit a home with a newly installed high efficiency heating system. Daniel from Goodman Manufacturing explains what makes a home heating system energy efficient. He recommends replacing the gas furnace approximately every 15 years and installing a modern gas furnace that includes variable speed. The Goodman Heat Exchanges comes with a 20-year lifetime warranty and a 10-year equipment replacement warranty. Daniel also explains how the thermostat contributes to the overall efficiency of the system and how digital technology is making home management much easier.