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Roof-mounted solar assists in cooling too

Maker of SolarWall is testing a new product for the Army that could provide both heating and cooling aids for buildings.

Conserval Engineering is testing a new product with the U.S. Army based on its original solar thermal wall panels that could help cool a building in addition to helping heat it up, the company announced today.

The company is best known for its SolarWall corrugated galvanized-steel solar collectors that can be used to heat a building's HVAC (Heating, Ventilating, and Air Conditioning) system as a way to save energy and bring down heating costs. It's used mainly on commercial, industrial, or large apartment buildings with vast wall space. The National Renewable Energy Laboratory, for example, installed a solar collector air heating system from SolarWall for its Research Support Facility.

SolarWall air heating system panels are mounted on the Research Support Facility at the National Renewable Energy Laboratory in Golden, Colo. NREL/U.S. Department of Energy

Conserval Engineering's new product, NightSolar, employs technology that works akin to the Nocturnal Radiation principle, in which a large body, like the Earth, for example, after spending a day absorbing heat from the sun, radiates that heat back into the cold night air.

SolarWall air heating systems are attached to south-facing walls so they can absorb long-wave radiation delivered by the sun (aka heat) during the day and transfer that heat to passed air via the building's HVAC system. The new product does that and its opposite. Connected to air handlers or an air conditioning system, the NightSolar roof panel can also draw the heat from warm air inside a building and transfer that heat out into the cooler night air.

As with the heating version, the NightSolar system is limited in function and is an aid toward building energy efficiency but not really a solution.

For example, it can only chill air 10 degrees Fahrenheit below the building's ambient temperature, and only works between sunset and sunrise, according to company statistics.