Energy performance of a bedroom task/ambient air conditioning (TAC) system applied in different climate zones of China

Highlights: • A CFD study was conducted on TAC system applied in different climate zones. • RSM method was used to predict energy consumption of TAC system. • Total energy consumption in summer ranged from 0 to 58.33 kWh in different cities. • Increasing the t_oz can reduce energy consumption by 23.42%–36.23%. • VAT (variable air temperature) operating mode can help save energy consumption. Task/ambient air conditioning (TAC) system applied to bedrooms has been investigated and its energy efficient performance reported. To promote the application of bedroom TAC to a larger region, a numerical study was carried out on a bedroom TAC system applied in five different climate zones. To simplify the numerical study, response surface methodology (RSM) was used to predict operating power of TAC based on CFD results. It's found that the daily energy consumption in the typical day was from 0 kWh in Kunming to 1.27 kWh in Shanghai, the averaged daily energy consumption varied from 0.47 kWh in June to 0.56 kWh in August for Guangzhou, and the total energy consumption in summer ranged from 0 kWh in Kunming to 58.33 kWh in Guangzhou. Meanwhile, the operating time of the TAC were also different between these five cities. In order to save energy, different set points of t_oz (average air temperature in the occupied zone) were investigated. It's found that increasing the t_oz from 24 to 25 °C can reduce energy consumption by about 23.42% in Shanghai to 36.23% in Beijing. Besides, the energy saving potential using two operating modes were compared: variable air flow rate and variable air temperature.