Abstract: To reduce the power consumption of air conditioning when using fresh air function, a technical scheme using heat pump technology for heat recovery of exhaust air is proposed. A 3-horsepower air duct unit is selected as the research object. Using Midea's self-developed refrigeration system simulation software MCOOL under Nanjing city meteorological conditions, theoretical analysis is carried out on its energy-saving effect and economic indicators. The results show that compared with the basic air duct unit, for cooling and heating conditions, under the same capacity, exhaust heat recovery technology can reduce the compressor frequency by 3 Hz~15 Hz and 1 Hz~5 Hz respectively. The new technology can save 330.5 kW·h of electricity in the cooling season and 304.6 kW·h of electricity in the heating season, with an annual electricity savings of up to 635.1 kW·h, and the energy-saving effect is significant. The additional cost of the exhaust module is estimated, and the return on investment (ROI) is calculated to reach 83.2%, indicating a high economic value.

Key words: AC with fresh air function, Simulation, Heat recovery, Economy analysis