OWNERS: Family who built an energy efficient home 30 years ago needed a new heating and hot water system. They really wanted to get off fossil fuels.


  • Originally built in 1990 but super-insulated
  • Semi-tight construction
  • 3,000 sq. ft.
  • Original fuel oil furnace and hot water heater
  • Pond close by

Original mechanical equipment was at end of life. Family consumed about 750 gals of fuel oil per year. It was dirty, smelly, and leaky. The homeowners were handy and could maintain the system mostly by themselves, but they wanted to move past a reliance on fossil fuels.


  • Replace old heating and hot water system
  • Reduce yearly costs to heat space and hot water
  • Get rid of smelly old fuel oil system
  • Add comfort with air conditioning and dehumidification


  • Blower door assisted air sealing
  • Installation of a 4-ton Water-to-Air Heat Pump connected to existing ductwork
  • Pond adjacent to house was expanded to accommodate pond loop heat exchanger


30% federal tax credit (state rebates were not available at time of installation)

Electricity went up $282/year but the homeowners saved $2,471 per year by eliminating their fuel oil bill. Payback for new system was less then five years