Solar Heating with Dynamic Opaque Walls and Roofs

Please note: The attached file below contains a paper linked to a presentation in pdf format from the BEST5 conference. Open with Adobe Acrobat for best results.

Heating for space heating, water heating, and clothes drying, is the largest site energy end use in many buildings. In residential buildings, it can be as high as two-thirds of the total site energy need and similarly high in laboratory buildings and many commercial buildings with high ventilation requirements. Traditionally the opaque portions of the building envelope have been treated only as a barrier to air and moisture flow and did not contribute to energy supply from the large surfaces subjected to daily solar heating. Over the past 18 years, American Solar, Inc. has used heated air recovered from the solar heating of “conventional” weather tight metal walls and roofs to deliver heat energy to more than 30 buildings. These have included all the largest solar air heating roofs in North America, with one roof more than 200,000 square feet.

The buildings have included; industrial, agricultural, laboratory, office, and residential. The uses of solar heat have included: direct space heat, air-to-water preheat for domestic hot water, heat pump preheat, air conditioning reheat, radiant floor heating, and equipment heating. Almost all of the installed systems have been monitored, including three that have been extensively monitored under DOD ESTPC and USDA contracts for up to one year. Those systems have generated performance algorithms that enable performance to be predicted in all US locations using available TMY and solar position data. This paper presents results from the past 18 years of development ,with specific examples from the testing, sources of information on research reports, and recommended future directions.