By Samuel Jacobs, Senior Engineer: Mechanical, WSP in Africa
Designing HVAC for healthcare in Africa is not just about meeting international standards but about making those standards work in environments defined by power constraints, supply chain limitations, and long-term operability challenges.
On projects such as the Roha Advanced Multi-Specialty Hospital in Addis Ababa, that balance becomes a significant undertaking. This 40,000 m² facility, with 350 beds and eight operating theatres, is being developed to meet international clinical standards and target EDGE certification.
African challenges
In many markets, HVAC strategies often assume stable power, consistent water supply, and readily available maintenance support. In much of Africa, those assumptions do not work. Power reliability, generator backup, water storage, and long-term operability all need to be considered from the outset. Equipment availability and supply chains also play a role, with components often imported and subject to extended lead times.
A single HVAC system is rarely able to address all the competing requirements of a modern hospital. Clinical safety, energy efficiency, flexibility, and resilience often pull design decisions in different directions. On Roha, the response was to adopt a hybrid system that separates and manages these demands more effectively.
Understanding the system
At the centre of the system is a chilled-water plant supplying air-handling units (AHUs). These units are responsible for managing the external air load, ensuring that conditioned fresh air is delivered in a controlled manner. In critical spaces such as operating theatres and MRI suites, these central systems manage the full thermal load to maintain strict environmental conditions.
To address internal loads more efficiently, Thermally Activated Building Systems (TABS) are used. These systems circulate high temperature chilled water through concrete slabs, providing radiant cooling and reducing the burden on high-airflow systems. By stabilising internal temperatures and managing peak loads, TABS contributes to both efficiency and system resilience.
Variable Refrigerant Flow (VRF) systems are then used to address the remaining internal loads and provide individual room-level temperature control. In a multi-speciality hospital, where occupancy and usage vary significantly between spaces, that level of control is essential.
More than temperature control
Airflow directly affects infection control and patient safety. Standards such as ASHRAE 170, with supporting standards like HTM 03-01 where necessary, define how air must be supplied, filtered, and distributed across different clinical spaces. Operating theatres, isolation rooms, and sterile processing areas all have specific requirements for ventilation rates and pressure relationships.
Air must flow from areas of higher positive pressure, such as sterile spaces, to areas of lower or negative pressure, preventing contaminants from entering critical environments.
This requirement has implications beyond mechanical design. On Roha, the HVAC strategy influenced architectural layouts and operational planning. The arrangement of operating theatres, isolation rooms, and adjacent spaces needed to support natural airflow paths that align with pressure zoning requirements. This required close coordination between engineers, architects, clinicians, and operations teams from the early stages of design.
Shaping the design
Sustainability targets, including EDGE certification, introduce an additional layer of complexity. Reducing energy and water consumption depends on both system design and building envelope performance.
By reducing peak loads, it becomes possible to design smaller, more efficient systems with lower airflow requirements. This has a direct impact on both capital cost and operational energy consumption.
In African healthcare facilities, where HVAC systems can account for a significant portion of total energy use, these efficiencies are not optional but central to long-term viability, particularly in private healthcare environments where operational costs are closely scrutinised.
Resilience, in this context, is closely linked to flexibility. A hospital is not a static environment. Different departments operate on different schedules, with varying load profiles throughout the day, week, and year. Systems need to respond to these changes without compromising performance in critical areas.
Data-led insights
Data and monitoring are increasingly important in managing this complexity. Building management systems (BMS) allow for continuous tracking of performance against design intent, supporting optimisation, early fault detection, and informed maintenance strategies. There is also growing potential for digital twin approaches to support long-term asset management and operational planning.
Looking ahead, hybrid HVAC systems are likely to become more prevalent in African healthcare projects. Advances in smart controls and real-time performance analytics will improve system integration and responsiveness. At the same time, the adoption of international standards will continue to establish a baseline for quality and safety.
State-of-the-art HVAC in African healthcare is not defined by the technologies used. It is defined by how well those technologies are integrated into systems that can be built, operated, and sustained over time. Projects like Roha demonstrate that it is possible to meet international clinical standards while addressing local constraints.
