In an effort to reduce their carbon footprint, the Fort Belvoir Army base in Fairfax County Virginia, recently installed a solar pool heating system for its Benyaurd Indoor Pool. The solar system was completed and connected on March 19, 2014. The solar pool heater is expected to save over $11,000 per year in energy use. This represents more than 40 percent of the annual cost to heat the indoor pool using natural gas.
Renewable Energy Focus
The Energy Policy Act of 2005 (EPAct 2005) established a number of energy management goals for Federal facilities and fleets. Executive Order (E.O.) 13423, Strengthening Federal Environmental, Energy, and Transportation Management, was signed on January 24, 2007, to strengthen key goals for the Federal Government. It set more challenging goals than the Energy Policy Act of 2005 (EPAct 2005) and superseded E.O. 13123 and E.O. 13149. E.O. 13423 requires Federal agencies to reduce energy intensity by 3% each year, leading to 30% by the end of fiscal year (FY) 2015 compared to an FY 2003 baseline. This goal was given the weight of law when ratified by EISA 2007. Accordingly, the Fort Belvoir Army base set its energy reduction goal at 30 percent by fiscal year 2015.
The Solar Pool Heating System
The solar pool heater works in combination with the existing natural gas fired heater. The gas heater will be utilized on days when the sun’s radiant energy is suboptimal. The system sends filtered pool water to the solar collectors when usable solar energy is available. Pool water is heated as it flows through the collectors before being returned to the pool. When the preferred temperature is reached, the solar system is bypassed, and pool water completes its normal circulation loop.
There are 80 4’ x 12’ Aquatherm Solar Industries solar collectors heating the pool with a total of 3,000 square feet of collector area. A SPEC Model-95 pump was installed downstream from the filter functioning as an inline booster pump. When the solar is on, the 5-horsepower pump sends 260 gallons per minute through the collectors.
Instead of screwing attachments to the roof membrane, the collector array was mounted to on a long-lasting composite wood-alternative, which was secured to the membrane roof with an adhesive and sealant, as well as additional pieces of the same membrane material.
Solar pool heating for the Benyaurd Pool is the most cost-effective form of pool heating, with no additional operating cost, low maintenance and a limitless supply of heat from the sun. When the sun’s intensity permits and ambient outside temperature is above 40- to 50-degrees Fahrenheit, the solar system is the primary source of heating the pool. The system will raise the unheated water temperature by 10 to 15 degrees Fahrenheit until the pool’s desired water temperature is reached.
The solar system used to heat the pool was manufactured by Aquatherm Industries, Inc. of Lakewood, New Jersey, and is specifically designed for low-temperature applications. The unglazed solar thermal collectors can efficiently heat water to a maximum temperature of up to 100°F – perfect for heating a swimming pool. The polymer solar collectors are constructed of durable, UV-resistant polypropylene and have an average life expectancy of 15 years according to Aquatherm.