Mun, H.-S., Dilawar, M. A., Rathnayake, D. et al. 2021. Effect of a geothermal heat pump in cooling mode on the housing environment and swine productivity traits. Applied Sciences 11(22), 10778.

This study compared the effects of the cooling mode of a geothermal heat pump (GHP) system with those of a traditional cooling system (ventilation fans) inside a pig house on the internal house temperature, harmful gas emissions, and the growth performance of the pigs. During the 19-week experimental period, the temperature inside the house connected to the GHP cooling system was significantly lower (p < 0.05) than that of a house with a conventional cooling system. Similarly, the temperature–humidity index (THI) was significantly reduced (p < 0.05) in the GHP cooling system-connected pig house. Furthermore, the concentrations of ammonia (NH3) and hydrogen sulfide (H2S) were also decreased significantly in the GHP-installed pig house (p < 0.05). However, no differences were observed in the concentrations of particulate matter (PM2.5) and formaldehyde (p > 0.05). The pigs reared in the GHP-equipped pig house gained significantly more weight (p < 0.05) by the end of the experiment. The GHP cooling system can therefore be implemented as a renewable, environmentally friendly energy source in pig farms for sustainable swine production without adversely affecting the productivity parameters.