Field Test and Economic Analysis of Energy-Saving Renovation for an Old Nursery Pig Building in Beijing, China

Highlights An old nursery pig building was retrofitted to potentially improve envelope insulation capacity. A mathematical theory based on coal consumption was established to evaluate energy efficiency of insulation renovation for a nursery pig building. The heat loss of the nursery pig house with 90-mm-thick extruded polystyrene boards was 60% lower than that without the materials. Ground source heat pump and air source heat pump are economical and environmental-friendly heating systems. Abstract. Appropriate renovation of old buildings is critical for energy-efficient pig production. Currently, energy consumption, especially coal consumption, keeps on rising in the production. Therefore, it is essential to develop energy-saving renovation methods for old nursery pig buildings and use cleaner heating energies. A mathematical theory based on coal consumption was established to evaluate energy efficiency of insulation renovation. Two nursery pig houses were tested in this experiment. One was the retrofitted house with the 90-mm-thick extruded polystyrene boards embedded onto outer walls, and the other one was served as a control house without those insulation materials. The results show that the air temperature and inside surface temperature of the retrofitted house were significantly higher than those of the control house in winter. Therefore, though adding insulation layers to walls, the envelope insulation capacity was improved. Meanwhile, the heat loss of the retrofitted house was 60% lower than that of the control house (11.08 W m-2 vs. 27.93 W m-2), when the theoretical ventilation rate was 1560 m3 h-1. In addition, with the prohibition of the coal usage in forseeable future of China, the ground source heat pump and air source heat pump can be economical solutions for heating systems with clean and renewable energy.