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ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Publications at this Location » Publication #342031
Title: Comparing radiant heater performance using spatial modeling

Author
item LINHOSS, JOHN - Mississippi State University
item Purswell, Joseph - Jody
item DAVIS, JEREMIAH - Auburn University
item ZHAOFEI, FAN - Auburn University

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2017
Publication Date: 7/25/2017
Citation: Linhoss, J.E., Purswell, J.L., Davis, J.D., Zhaofei, F. 2017. Comparing radiant heater performance using spatial modeling. Applied Engineering in Agriculture. 33(3):395-405. https://doi.org/10.13031/aea.12108.
DOI: https://doi.org/10.13031/aea.12108

Interpretive Summary: Radiant heaters are the preferred method of providing supplemental heat in poultry houses because they heat the floor and chicks directly. Heating the floors and chicks allows for a broad range of thermal comfort options and birds are able to thermoregulate through movement and behavior. Heat distribution at the floor is commonly evaluated using thermal cameras which provide visual depictions of floor temperature distributions but cannot directly energy transmitted to the floor or surrounding surfaces. The objective of this study was to measure the radiant energy emitted by round radiant heaters reaching the floor of a poultry house and compare the resulting heater gross radiant coefficients (GRC). Radiant flux measurements (n=160 per heater) were taken within the heated area of six round radiant heaters with a nominal rated output of 40,000 BTU/h. Radiant flux data were collected at heater canopy elevations of 4, 5, 6, and 7 ft above the measuring plane. Total heated area ranged from 150 to 661 sq. ft. between 4 and 7 ft canopy elevations. Mean radiant energy reaching the measuring plane was 8666, 10236, 11397, and 14638 BTU/h for canopy elevations of 4, 5, 6, and 7 ft, respectively. Mean gross heat input was 36715 BTU/h and ranged from 32040 to 44937 BTU/h across all heaters. GRC ranged from 0.21 to 0.41 and increased with heater elevations, indicating that most of the fuel consumed during combustion was used to convectively heat the air or radiated away from the floor.

Technical 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.