*3.2. Electricity Consumption, CO<sup>2</sup> Emissions, and Cost Savings*

Table 2 lists the daily electricity consumption and cost analysis per day in both experimental houses. The daily electricity consumption during the weaning, growing, and finishing periods were decreased in the AHP house. The decrease in average daily electricity consumption in the AHP house was 63.5%.


**Table 2.** Energy consumption and heating costs of the pig houses during the various growth periods.

Electricity consumption was determined using an electric meter installed for each house for every day (8:00–20:00) and night (20:00–8:00), and was summed per day. Carbon dioxide (CO2) emissions were evaluated based on electricity consumption per day. The used conversion factor was 1 kWh = 0.483 kg CO<sup>2</sup> emissions [27]. Cost was estimated according to electricity consumption per day. The current value of 1 kWh electricity = 39.2 South Korean Won, and 39.2 South Korean Won = 0.033 USD was used (KEPCO, September 2020).

Consequently, a significant decline of the daily electricity cost was also observed in the AHP house relative to the control house. During the finishing period, the electricity consumption was reduced drastically in the AHP house, and the reduced average daily electricity cost was 63.6% compared to the control pig house. The total CO<sup>2</sup> emission was decreased in the AHP-installed house, and the average daily reduction was 63.49% compared to the control house.
