Comparing Radiant Heater Performance Using Spatial Modeling

Abstract

Abstract. Radiant heaters are the preferred method of providing supplemental heat in poultry houses because they heat the floor and chicks directly to create a suitable microclimate by allowing for a range of thermal comfort options. Heat distribution at the floor is commonly evaluated using infrared thermography, which provides assessments of floor temperature distributions but cannot directly compare energy reaching the floor to energy consumed. The objectives of this study were to develop a system to measure the radiant energy emitted by round radiant heaters that reached the floor (measuring plane), use spatial modeling to estimate total radiant flux output at the measuring plane, and compare heater gross radiant coefficients (GRC). A radiant heater test stand was constructed over a set of linear arrays mounted with thin-film radiant flux sensors. Radiant flux measurements (n=160 per heater) were taken within the heated area of six round radiant heaters with a nominal rated output of 11.72 kW. Radiant flux data were collected at heater canopy elevations of 1.22, 1.52, 1.83, and 1.98 m above the measuring plane. Results from non-linear regression analysis showed that for all heater and elevation combinations, the radial distance from the heater center axis to 95% of the final asymptotic value was 4.71 m or less. Total heated area ranged from 13.90 to 61.46 m2 between 1.22 and 1.83 m canopy elevations. Mean radiant energy reaching the measuring plane was 2.54, 3.00, 3.34, and 4.29 kW for canopy elevations of 1.22, 1.52, 1.83, and 1.98 m, respectively. Mean gross heat input was 10.76 kW and ranged from 9.39 to 13.17 kW across all heaters. GRC ranged from 0.21 to 0.41 and increased with heater elevations. Keywords: Brooding, Gross radiant coefficient, Heater performance, Radiant flux, Radiant heating.