Evaluation of a novel, low-cost plastic solar air heater for turkey brooding

Abstract

Solar heat could displace fossil fuel to reduce energy cost for brooding livestock and poultry. A transpired solar collector (TSC), consisting of a perforated dark-colored metal surface, can provide considerable heating but metal TSCs (mTSCs) are expensive. Since a perforated black plastic sheet will be less-expensive, a plastic TSC (pTSC) was evaluated. The 1.49 m2 pTSC (porosity of 1.2%) supplemented a propane heater in a room housing 240 turkey poults; an adjacent room without a pTSC, with 240 poults was the control. Monitoring was performed over two flocks of poults. A custom-built controller bypassed the pTSC during nighttime or when the room did not require heating to bring in fresh air. The pTSC gave a maximum temperature rise of 25.4 °C at a solar irradiance (I) of 882 W/m2 and suction velocity (Vs) of 0.033 m/s over 15 min. Over 178 h of operation, with an average I of 668 ± 295 W/m2 and average Vs of 0.036 m/s, the pTSC increased air temperature by an average of 8.1 ± 4.2 °C. Probably due to higher ventilation rate and an oversized propane heater, propane use was not reduced in the Test room with the pTSC vs. the Control room. The Test room had lower CO2 and CO concentrations due to higher ventilation, which may have improved turkey performance. The metal TSC gave a slightly higher temperature rise at a lower Vs but the less-expensive pTSC could be a more cost-effective solar air heater that could readily be scaled up for agricultural and other applications in many parts of the world. Scale-up considerations seem feasible and are presented for a 10,000-poult brooder barn.