## 1 Introduction  
Surgical site infections are common in hospital settings [1] and can be caused by many factors, including ventilation [2]. Fungal growth problems have always existed in hot and humid areas [3]. Some postoperative patients with fungal infections in hospitals were reported due to the discharge of fungal spores from contaminated air conditioning systems [3, 4]. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)/American Society of Health Care Engineering (ASHE) Standard 170, Canadian Standards Association (CSA) Z317.2-15 standard, and FacilityGuidelines Institute (FGI) requirement all suggest a minimum ventilation rate, air temperature, and relative humidity (RH) for operating rooms (ORs) [5; 6; 7]. The indoor humidity level was associated with human thermal comfort [8], indoor air quality [9], and the operating efficiency of the air conditioning system [10]. Environmental monitoring and control are important issues in healthcare settings to ensure the health and safety of patients and medical staff. To minimize infection risk and maintain human thermal comfort, the ASHRAE/ASHE Standard 170 suggests the levels of temperature/RH in ORs [5]. The ASHRAE \"HVAC Design Manual for Hospitals and Clinics\" [11] also recommends the level of design parameters in the ventilation system of an OR. The dehumidification systems used in hospitals include conventional HVAC, LDAC and RDAC. Conventional HVAC systems lower the temperature of mixed air (outdoor and return air) through the air conditioning of chilled water coils below the dew point temperature to remove moisture (latent heat removal) [12]. This system tends to lower the temperature of mixed air, which must then be warmed using heated water coils to meet temperature and comfort requirements, thus wasting energy. Since conventional HVAC systems may not effectively control the temperature of outflow chilled water, their usage likely increases the RH of a room [12]. Furthermore, the conventional HVAC system uses the vapor-compression recycled design, whose refrigerant may be associated with global warming. Therefore, LDAC and RDAC systems are recommended for ventilation [13]. In contrast, LDAC systems have such advantages as high dehumidification efficiency, low energy consumption, and a dehumidification efficiency not affected by time [14; 15]. In hot and humid areas, the LDAC system has been proposed as an alternative system due to its advantages, such as removal of the air latent load and pollutants from the process air and reduction of electrical energy [15]. These advantages are also present in RDAC systems [16]. Lithium chloride is the commonly used desiccant because of its property of low vapor pressure and stability [15] as well as its thermo-chemically synergistic kill effect (up to 99.99%) on anthrax spores and their surrogates [17]. Thus, the LDAC system is similar to a wet dust collector to filter airborne particulate matters [15]. These LDAC systems transfer and disperse water molecules from the high partial pressure of water vapor to the low partial pressure of water vapor to achieve moisture transmission and dehumidification (latent heat processing) [14]. A salt or triethylene glycol solution is used to adjust the liquid desiccant concentration and temperature in order to achieve dehumidification. A typical LDAC system is divided into dehumidification and regeneration sides. When moist air enters the dehumidification side, it comes into contact with the low-temperature dehumidified liquid (with low vapor pressure) to perform heat exchange and expel dry warm air. Then, the moisture (now high-temperature humidified moisture with high vapor pressure) flows to the regeneration side where it comes into contact with the airflow from this side and discharges the humidity into the air to achieve the regeneration of the solution [15]. In 2010, [PERSON] et al. concluded that RDAC systems consume less energy and are more environmentally friendly than conventional HVAC systems [9].