BPI Building Perfornnce Institute


Entry Level Certificate of Knowledge

New York Solar Energy Society

sharp solar electricity

Solar Certified Installer

conergy pv system design and installation
PV System Design and Installation Certified * Solar Water Pumping Solutions Certified

American SOlar Energy Society

fronius inverter design and installation
Inverter Design and Installation qualified

new york city contractor
Licensed Contractor

license #1218929

Efficiency First


Home Performance

dsire usa

solar hot water

Solar Hot Water systems produce more energy for your investment than any other renewable resource, making it the smartest and most practical first choice toward a more efficient, greener lifestyle. Of all the renewable energy options, Wind, Photovoltaic, Geothermal; Solar Thermal’s initial investment is much less and the return on investment is much shorter.


Solar thermal systems heat your domestic water similar to existing (traditional) hot water systems. Efficient systems can convert up to 70% of the sun’s energy and deliver that directly to you.

Generally there are two types of solar thermal systems:


Direct systems are basic “open loop” designs. The water is heated directly by the sun in solar collectors mounted on the roof and that water is tied directly into the domestic hot water system. A thermostatic control signals when the solar collector is ready to heat water, sends a signal to the pump, which circulates cold water into the collector and heats the water. The heated water is stored in a conventional hot water tank.

During high use periods and or low sun irradiance the domestic water will be heated through supplemental energy sources; electricity, gas, oil.

This type of direct solar thermal system that circulates pure potable water is more efficient than indirect systems. However, they require more maintenance to keep the pipes clear of mineral deposits, and function best in warmer climates, where there is little chance of freezing temperatures.


Indirect systems are referred to as “closed loop” systems.  These solar thermal systems use a fluid with a low freezing point (glycol solution) to absorb the radiant energy from the sun.  The fluid is heated in the solar collector tubes mounted on the roof and circulated into a heat exchanger where it warms cold water heading into a hot water tank. Raising the temperature of the cold water before it gets into the hot water tank reduces the energy demand required to heat the domestic hot water.

The fluid solution flows back into the solar collector without mixing with the domestic hot water supply.
Indirect solar systems are utilized in climates that experience freezing temperatures over extended periods.


The Solar Rating and Certification Corporation (SRCC) is an independent non-profit organization that was formed in 1980, they develop and implement certifications to regulate the flow of quality products that enter the market. The Federal government along with numerous states and utility companies use these standards and the certifications from SRCC to base their tax credits and rebates.  For more information on solar thermal, State and Federal tax rebates and incentives visit these sites:


Drum River Consultants • 1707 Dean Street, Brooklyn, NY 11213 • audits@drumriver.com • 718-744-5727