Experimental study on double heat pipe fresh air unit based on temperature and humidity separate control air conditioning system

To enhance the summer dehumidification performance of traditional air conditioning systems, a double heat pipe fresh air unit based on temperature and humidity separate control air conditioning system was designed. Performance tests were carried out under three working conditions: standard working conditions, rainy season and typical summer days, with an air supply volume of 300 m³/h as the benchmark. The results show that the cooling capacity of the surface coolers under the three working conditions is 5 kW. The dehumidification capacity of the fresh air unit equipped with U-shaped heat pipes is increased by 0.2 kg/h compared with the single surface cooler. The dehumidification capacity per kilogram of fresh air is 14 g in the rainy season and 12 g on typical summer days. The dehumidification performance is better than that of a single surface cooler. The double heat pipe fresh air unit reduces the cooling capacity of the heat pump unit by 0.5 kW by recovering the exhaust air's residual cooling, verifying the energy-saving characteristics of the heat recovery heat pipe heat exchanger. This study addresses the high energy consumption and insufficient dehumidification capacity of traditional systems, and provides a new energy-saving dehumidification solution for buildings in areas with hot summers and cold winters.