Hvac Design for Hospitals

Design Requirements

Comfort: To provide a comfortable indoor environment for patients and healthcare workers, in general, the temperature of the ward should be maintained at 22℃ - 25℃ and the relative humidity at 40% - 60%. Different areas such as operating rooms and labor and delivery rooms may have more stringent temperature and humidity requirements.

Infection control: The spread of airborne bacteria, viruses and other microorganisms is controlled through rational airflow organization and ventilation systems to reduce the risk of cross-infection. For example, a unidirectional or turbulent flow system is used to ensure that clean air flows from clean areas to contaminated areas.

Air purification: Highly efficient air filtration systems are used to remove airborne contaminants such as dust, pollen, bacteria and viruses to provide high quality air. A minimum of MERV 13 filters are usually required, and higher levels of HEPA filters may be needed in specialized areas such as intensive care units (ICUs), operating rooms, etc.

Reliability: Hospital HVAC systems must be highly reliable to ensure continuous and stable operation. Redundant designs, such as standby units and dual power supplies, are used to prevent system failures from affecting medical work.

Flexibility: Considering the development and functional changes of the hospital, the HVAC system should have a certain degree of flexibility, which makes it easy to carry out remodeling and expansion.

System Design

Cooling and heating source system

Selection: A variety of cooling and heating source methods can be used, such as chiller + boiler, ground-source heat pump, air-source heat pump, etc. Selection of suitable cooling and heating sources is based on comprehensive consideration of the hospital's scale, geographical location, energy supply and economic factors.

Standby: In order to ensure the reliability of the system, the cold and heat source equipment should be equipped with a standby unit, so that when one unit fails, the standby unit can be put into operation in a timely manner to ensure the hospital's cooling and heating needs.

Air conditioning system

Operating room: an independent purified air-conditioning system is usually adopted to ensure air cleanliness and temperature and humidity control in the operating room by using unidirectional flow or turbulent flow.

Wards: Fan coils plus fresh air system can be used to facilitate the independent adjustment of temperature and humidity in each ward while providing fresh air.

Public areas: such as waiting areas and corridors, all-air systems can be used to meet the air conditioning needs of large areas by centralized air treatment.

Ventilation System

General areas: natural ventilation combined with mechanical ventilation is used to ensure indoor air circulation and air exchange.

Special areas: such as infectious disease rooms, negative pressure isolation wards, etc., a negative pressure ventilation system should be used to ensure that indoor air can only flow from the clean area to the contaminated area, preventing the spread of germs to other areas.

Control system

Intelligent: Adopt advanced building automation control system (BAS) to realize real-time monitoring and automation control of HVAC system. Through sensors monitoring indoor and outdoor environmental parameters, equipment operation status, etc., the operation of air-conditioning equipment is automatically adjusted to achieve the best energy-saving effect and comfort.

Zoning control: According to the functions and usage characteristics of different areas of the hospital, zoning control is carried out so that the air conditioning parameters can be flexibly adjusted according to the actual needs of each area.

Noise and vibration control

Equipment selection: Choose low-noise, low-vibration HVAC equipment, such as high-efficiency, low-noise fans and pumps. In the process of equipment bidding and purchasing, the requirements for noise and vibration control are clarified to ensure that the equipment meets the standards.

Installation and vibration damping: When installing the equipment, adopt suitable vibration damping measures, such as installing vibration damping pads, vibration damping hangers, etc., to reduce the vibration generated by the equipment operation to be transmitted to the building structure.

Energy-saving Measures

Frequency conversion technology: Adopt frequency conversion speed control technology to automatically adjust the operating frequency of air-conditioning equipment according to the actual load demand and reduce energy consumption.

Heat recovery: Setting up heat recovery devices, such as air - air heat recovery device, water - water heat recovery device, etc., to recover heat or cold from the exhaust air and use it for preheating or pre-cooling the new air, so as to improve the efficiency of energy utilization.