Rooftop-PV-Driven Air Source Heat Pumps in Mechanically Ventilated Broiler Houses: An Integrated Assessment of Thermal Environment, Energy, and Carbon Emissions in South Korea

In Korean broiler houses, an evaporative cooling pad (ECP) and a kerosene heater conventionally provide cooling and heating. However, ECP struggles to maintain the optimal rearing temperature under Korea’s hot, humid summer conditions, while winter kerosene heating produces on-site carbon emissions. This study evaluated replacing the conventional cooling and heating system with a rooftop-photovoltaic (PV)-driven air source heat pump (ASHP) that electrifies both cooling and heating. Using a building energy simulation model with a field-validated thermal environment component, 24 scenarios combining climate zone, weather condition, rooftop PV installation, and environmental control strategy were evaluated for thermal environment, energy, and carbon performance. The ASHP reduced setpoint exceedance hours (at least 2 °C) from an ECP average of 387 to 0 h·year−1 and eliminated heat stress hours (temperature–humidity index ≥ 78) but fully electrified the load, raising annual electricity demand to 192–204 MWh. Rooftop PV (323–382 MWh·year−1) exceeded this demand by day, giving 37–38% self-sufficiency and net-negative operational emissions under an export credit approach. Only ASHP + PV removed on-site fossil fuel, making it the substantive decarbonization pathway. PV coupling yielded net revenue with an undiscounted simple payback of 4–13 years. Combining secure thermal control, on-site decarbonization, and self-consumption-oriented operation, ASHP + PV is a promising option for climate-resilient, low-carbon broiler production.