Overview of Heat Transfer
Regardless of the season, warm air will always move warmer areas to cooler areas. In the winter, this means that warm air from living spaces will move into the attic, where it disappears. In the summer, the warm air in the attic will seep down into cooler living spaces. Both seasonal situations cause an HVAC system to run more to compensate for the heat transfer.
Lower Utility Costs
The United States Environmental Protection Agency estimates that homeowners can save about 15 percent on their heating and cooling costs by sealing homes and adding insulation to crawl spaces and attics. People living in northern areas will experience greater savings than those in the South because of climate factors, house construction styles, and the types of fuel used.
The average life expectancy of an HVAC system is between 15 and 20 years, but this time span could fall short for systems that need to run longer or more often due to insufficient protection. With tighter sealing and more layers in place, furnaces and air conditioners work less to maintain comfort. This translates into extended life for these systems, because they run for fewer hours and experience less wear and tear.
Running a furnace and air conditioner more often has a direct correlation on a home's overall carbon footprint because of the amount of greenhouse gases that enter into the air. Fiberglass insulation is an environmentally friendly choice because it can contain up to 60 percent of recycled content. Cellulose may contain up to 80 percent of recycled materials. Using recycled materials helps create space in landfills, and it reduces the amount of materials that enter the waste stream every year.
Construction standards have changed, especially since 1980. Anyone owning a home built before 1980 that has not been inspected for energy-efficiency is likely to have issues with insufficient weatherization. Installing additional insulation can have a positive impact.