Comparative Analysis of Energy Consumption, Indoor Thermal–Hygrometric Conditions, and Air Quality for HVAC, LDAC, and RDAC Systems Used in Operating Rooms

Tsung-Yi Chien,Feng-Jen Wu,Ting-Hsin Pan,Ching-Chieh Liang,Chi-Tsung Chen,Gwo-Hwa Wan

doi:10.3390/app10113721

Abstract

As controlling temperature and humidity is crucial for maintaining comfort and preventing microbial growth, operating rooms (ORs) are the most energy-intensive areas in hospitals. We aimed to evaluate the energy consumption of three dehumidification air conditioning systems used in ORs and their corresponding air quality for ORs at rest. This study selected three ORs using a conventional heating, ventilation, and air conditioning (HVAC) system; a liquid desiccant air conditioning (LDAC) system; and a rotary desiccant air conditioning (RDAC) system, respectively. The indoor thermal–hygrometric conditions, air quality, and energy consumption of the ORs were monitored in this study. The median levels of relative humidity (RH) were 66.7% in the OR using the conventional HVAC system, 60.8% in the OR using the LDAC system, and 60.5% in the OR using the RDAC system. The median daily total energy consumption of the RDAC system (10.1 kWh/m2) and LDAC system (11.8 kWh/m2) were 28.12% and 16.54% lower, respectively, than that of the conventional HVAC system (14.1 kWh/m2). The PM≥0.5 levels and airborne bacterial concentrations in the ORs met the ISO 14644-1 Class 7 standard and China’s GB50333-2013 standard, respectively. The RDAC system was clearly superior to the LDAC and conventional HVAC systems in terms of energy consumption.

Highlights

Surgical site infections are common in hospital settings [1] and can be caused by many factors, including ventilation [2]
Our results indicate that rotary desiccant air conditioning (RDAC) systems are more energy efficient than either conventional HVAC or liquid desiccant air conditioning (LDAC) systems
We observed no correlation between indoor temperature and airborne bacterial concentration, differing from Fu Shaw et al We found no significant correlation between relative humidity (RH) and airborne bacterial concentration, but according to the suggestion of the ASHRAE/American Society of Health Care Engineering (ASHE) Standard 170, the RH level should be carefully controlled to prevent the risk of microbial growth [5]

Summary

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 Facility.

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Conclusion