For homeowners interested in reducing their personal carbon footprint through solar power but wanting to start off on a smaller scale than a whole-house option, an exciting, energy-saving solution will be available soon from heating and air conditioning leader Lennox Industries.  Expected to be available in 2009, Lennox’ new SunSource™ system is the industry’s first integrated, solar-assisted residential heating and cooling system – and it uses just a single solar panel of about 200 watts. Featuring a patent-pending design, the innovative system is currently in full operation at multiple test sites throughout the country.

“The SunSource™ system provides any green-conscious consumer an effective introduction to how they can significantly reduce their personal carbon footprint through even a small-scale solar power application,” says Bill Cunningham, Lennox product manager.  Using renewable solar power displaces the power consumers purchase through their electric utilities, he points out.

The energy efficiency gains are quite significant, Cunningham says.  “ “For instance, on a standard AHRI cooling test with 95 degree outdoor temperature, the efficiency of the unit is increased by 6% when full sun is available.   This saves the homeowner by lowering cooling costs but also reduces the amount of power that must be generated and transmitted through the grid by the electric utility.

The single solar panel provides dc power to assist the fan  that moves air across the outdoor coil, a key part of any home comfort system. This fan has an ac motor for normal operation and a special dc motor that assists whenever sufficient sunlight is available.  “It is a form of hybrid drive: as the solar powered dc motor is able to take over the fan load, the ac motor just backs-off on power consumption.  This is a continuous transition, even on days with limited sun, the SunSource™ system takes advantage of the available solar resources and reduces energy usage,” Cunningham says.  Figure 1 shows the ac fan power on a day in early September.  It was a partly cloudy day and the temperature reached 96°F.  The sag in the ac power during the middle of the day is due to the solar motor taking over most of the load.

The system will initially be available in a heat pump model, he explains, since heat pumps are used throughout the year and offer homeowners the greatest benefit.  The approximately 3 ft. x 5 ft. solar panel can be easily installed by a Lennox dealer, with a variety of mounting options available.

While final AHRI ratings are not yet available for the system, seasonal efficiency  will be higher than the company’s  current top-tier heat pump.  Figure 2 is a cut-away view of the new Lennox SunSource Heat Pump.

 “Most of the additional cost for the SunSource™ system is associated with the solar panel and will adjust as solar panel pricing declines,” Cunningham notes.  “The final price will be set by our professional installing dealer base.”  The estimated payback period will vary, he says, depending on location, future electric rates, and the total cost of installation.  The federal 30% solar tax credit and state and local rebates  reduce the additional cost and  payback period.

As a compact and relatively inexpensive introduction to the energy-saving benefits of solar power, the Lennox SunSource™ system will have many advantages, Cunningham says.  “The system can help reduce peak demand, increase energy efficiency, and maintain homeowner comfort.  It’s an effective way for environmentally aware homeowners to get started quickly with solar.”

Figure 1. AC (Purchased) Fan Power on a Partly Cloudy Day in September

Figure 2. Lennox SunSource Heat Pump

You can sign up to receive more information on Lennox SunSource by visiting
http://www.lennox.com/products/sunsource.asp.