How to Design a Hospital's HVAC System – A Case Study

1 HVAC Capacity & Energy Design

The hospital’s HVAC system was engineered to meet high patient throughput and 24-hour operational demands.

• Total cooling load: 17,325 kW

• Total heating load: 7,783 kW

• Cooling index: 112 W/m²

• Heating index: 50 W/m²

A 30% capacity margin was reserved to accommodate peak medical demand and future expansion. The cooling system is centered around six centrifugal chillers, including a variable-frequency unit for efficient part-load operation. Heating is provided by four atmospheric hot-water boilers, one of which supports dual-fuel (oil and gas) operation for enhanced reliability.

Special medical areas such as laboratories, clean operating rooms, and IVF departments are supported by independent air-source heat pump systems to enable early or delayed cooling and heating as required.

2 Air Conditioning Water System

The project adopts a variable-flow, single-stage pumping system on the load side combined with constant flow on the equipment side. Intelligent unit staging and differential pressure control optimize energy use under varying load conditions.

• Four-pipe systems serve maternity wards, NICUs, outpatient and emergency areas, and cleanroom spaces

• Two-pipe systems are used in standard functional areas

• Independent water loops support departments with special temperature and humidity requirements

During transitional seasons and winter, water-side free cooling via cooling towers supplies chilled water to interior zones, significantly reducing chiller runtime and operating costs.

3 Terminal & Air Distribution Systems

Public and high-traffic areas such as outpatient halls, waiting zones, pharmacies, and large laboratories use full-air systems with modular air handling units equipped with multi-stage filtration.

Smaller spaces—including consultation rooms, wards, and offices—are served by fan coil units with independent fresh air systems, ensuring both comfort and indoor air quality.

High-risk medical areas such as operating rooms, delivery suites, fever clinics, and autopsy rooms are designed with 100% fresh air direct-flow systems to meet strict infection control requirements.

4 Ventilation & Infection Control

To minimize the risk of airborne cross-infection, the hospital HVAC and ventilation systems are zoned by floor and function, maintaining precise pressure differentials that guide airflow from clean to contaminated areas.

Key features include:

• Dedicated exhaust systems for laboratories and pathology departments with high-efficiency filtration

• Independent exhaust and supply systems for central sterile supply areas

• Negative-pressure exhaust systems for toilets, soiled rooms, treatment rooms, and laboratories

• High-level exhaust discharge to ensure environmental safety

5 Intelligent Control & System Reliability

The HVAC system is fully integrated into the hospital’s Building Automation System (BAS), enabling real-time monitoring, automatic control, equipment interlocking, fault protection, and energy metering. This ensures stable operation, rapid response to changing loads, and long-term operational efficiency.

6 Project Value Highlights

• Designed specifically for women and children, prioritizing air quality, thermal comfort, and infection prevention

• Flexible four-pipe systems support early or delayed cooling and heating for sensitive medical departments

• Redundant and independent systems enhance reliability for critical care areas

• Energy-efficient design reduces operating costs while supporting 24/7 hospital operation

7 Project Summary

As an EPC general contracting project, this hospital HVAC system required a balance between technical excellence, operational reliability, and cost control. HVAC systems accounted for approximately 6% of the total project investment, with optimized allocation across cooling and heating sources, air and water systems, terminal equipment, and ventilation.

Through close coordination with the owner, EPC contractor, and medical process designers, the project successfully delivered a high-performance HVAC solution tailored to modern maternity and children’s healthcare facilities.