Biological Systems Engineering


Date of this Version



Published in TRANSACTIONS OF THE ASAE VOL. 36(2): MARCH-APRIL 1993, pp. 559-567. Copyright 1993 American Society of Agricultural Engineers. Used by permission.


A low cost, simple solar heating system consisting of an active collector with an In-Floor Heat Distribution and Storage (IFHDS) system was developed in response to the energy crisis of the 1970s. A two-dimensional finite difference model was developed and used to simulate the performance of IFHDS system cross-sections. Simulation runs were conducted with a steady-periodic model for the temperature of the solar-heated air in the IFHDS system cross-section. The steady periodic simulation results indicated IFHDS system energy efficiency increases with decreasing air temperature in the room above the IFHDS system, peak temperature of the solar-heated air in the IFHDS system cross-section, and required temperature of the IFHDS system floor surface. The results also indicated that energy efficiency increases as thermal storage mass thickness decreases. The thermal storage mass thickness should be the minimum necessary to meet the requirements for maximum permissible daily floor surface temperature fluctuation, or time lag between time of peak, solar-heated air temperature in the IFHDS system cross-section and time of peak floor surface temperature.