Mill Bay Home

The Project

A family from Mill Bay on Vancouver Island was building their dream home overlooking the ocean. The most important goal of this 9,000 square foot home was to counteract it's large size and leave as small a carbon footprint as possible. Geoexchange was an obvious choice, since it reduces the energy consumed for heating and cooling the home by up to 80%.  And in British Columbia, where the vast majority of electricity is generating using hydro, the emissions from running the systems would shrink to nearly zero.

The homeowners originally hired a local company to design the geoexchange system. While the design was functional, it was meant for a commercial building. The geoexchange design failed to optimize the capital and operating cost of the system. The homeowners went ahead with drilling the boreholes for their vertical geoexchange system, and in parallel approached CleanEnergy™ to review the system design.  The extensive experience of CleanEnergy’s engineers and designers led to an optimized system design, ultimately saving the homeowners over 40% of the capital cost of the system while still giving equivalent comfort, zoning and control.

CleanEnergy partnered with its local dealer, Pro Star Mechanical Technologies Ltd., who installed the units, ductwork and radiant floors. As the project manager, CleanEnergy was able to provide a turnkey solution including engineering design, project management, equipment supply and installation. 

CleanEnergy brings an optimized, fully managed product that creates customer value through balancing costs and benefits.
Owner of the Mill Bay Home

Geoexchange System Benefits

Carbon Emission Reductions
  • The annual carbon emission savings of the CleanEnergy geoexchange system is estimated at nearly 23 tonnes compared to a high efficiency natural gas system
  • This is the equivalent of planting fourteen acres of trees or taking 8 cars off the road every year
Operating Costs
  • The CleanEnergyTM system is estimated to save the homeowners over $44,000 over a ten year period based on the forecasted increased price of natural gas
  • The Mill Bay homeowners have an estimated annual savings of $3,139 on their heating, cooling and hot water costs compared to a high efficiency natural gas system

Equipment and System Benefits

Heat Pumps:

  • Three five ton WaterFurnace Envision forced air units
  • One five ton water to water unit that creates hot water for the radiant flooring and swimming pool

Ground Loop:

  • The loopfield consists of 36 boreholes to 175 feet deep, each loaded with 1” high density polyethylene pipe


  • Nine heating and cooling zones in the resident’s home maximize comfort while also conserving energy
  • Geoexchange provides simultaneous heating and cooling for the home
    • The swimming pool is heated during the summer by using the waste heat from the compressors in the heat pumps
  • Keeping the wine cellar cool in the winter provides increased heating efficiency for the heat pumps
  • The home is equipped with a humidity control system that provides a comfortable level of humidity all year round
  • The variable speed fans in the forced air units adjust with the energy load, providing increased energy savings
  • The desuperheaters capture the waste heat from the compressors in the heat pumps to provide approximately half of the home’s domestic hot water