Innovative HVAC system at Baragwanath hospital’s burns ICU enhances patient care

Technical input by Kamva Ndlala, Maninga Engineering consulting engineer, edited by Eamonn Ryan

Chris Hani Baragwanath Academic Hospital recently built an adult burns intensive care unit (ICU) – a key aspect of its efficient functioning was the HVAC system, aiming to optimise patient comfort and recovery conditions.

The Maninga Engineering project team (left to right): Daniel Delport, Lungelo Sibande, Kamva Ndlala, Sikhulile Nhassengo. All images supplied by Maninga Engineering.

The project, funded by a donation from Wits University alumni, was started in late 2021, with the goal to establish a state-of-the-art adult burns unit. Burn victims require specific environmental conditions due to the loss of their skin’s protective layers, making temperature and humidity control critical.

Following international standards, the burns ICU is maintained at a temperature range of 26°C to 28°C with humidity levels between 50-60%, significantly higher than typical healthcare settings.

Maninga Engineering lead engineer, Kamva Ndlala, details the technical aspects of the HVAC system installed. “We opted for hybrid air handling units with a three-stage filtration system. This includes primary, secondary, and tertiary (HEPA) filters to ensure the air is free from contaminants, especially crucial in an ICU environment. We also installed Daikin VRF (Variable Refrigerant Flow) units to aid in the conditioning of the air.”

The VRF technology was chosen for its ability to modulate based on fluctuating load demands within the ICU, ensuring energy efficiency without compromising on patient comfort or environmental control. Each room is maintained at positive pressure relative to corridors and external spaces, achieved through individualised air diffusers and VAV (Variable Air Volume) systems with room-specific sensors for precise monitoring and adjustment.

The project also grappled with energy efficiency challenges, particularly in humidification during winter. “To manage energy consumption effectively, we integrated a steam-to-steam humidifier. This innovative approach leverages existing hospital infrastructure, such as boilers, to minimise additional electrical load.”

ICU ward passage.

Commencing with groundwork in late 2021, the project moved into installation phases by 2023, with completion achieved recently. “It was a comprehensive undertaking from scratch. The entire structure was erected to meet the exacting standards required for a burns ICU.”

Throughout the project, collaboration with structural engineers and other consultants was pivotal. Ndlala highlights the seamless coordination with external partners in achieving project milestones.

Critical to the design and energy efficiency, was a pre-existing boiler at the hospital. Its vast capacity as a strategic advantage, Ndlala explains, “The hospital’s boilers, originally used for water heating, proved instrumental in our humidification strategy. By utilising steam from these boilers, we minimised additional electrical load and ensured consistent, isothermal humidification—essential for maintaining air temperature stability and system reliability.”

ICU ward room interior.

Ndlala emphasises the project’s commitment to sustainability and cost-effectiveness. “Our approach was to integrate sustainable solutions that leverage existing resources. This not only reduces operational costs but also enhances system reliability by avoiding unnecessary complexities in control mechanisms.”

Overcoming challenges

Reflecting on the project’s challenges, Ndlala cites space constraints as a significant hurdle. “Despite building from scratch, space limitations posed logistical challenges, particularly for accommodating the required airflow volumes. While the initial design accounted for technical requirements like double-skin ducting to mitigate noise and thermal loss—a critical factor in an ICU environment – on-site realities often presented unforeseen obstacles.”

Ndlala recounts one such challenge: “A misplaced pipe required careful coordination among contractors to ensure minimal disruption. However, the main issue was a face brick wall that initially hindered airflow from the plant room to the ICU. Fortunately, once removed, internal installations proceeded smoothly.”

“Meticulous coordination among the Maninga Engineering team and various contractors was imperative as the project encompassed wet services, medical gases, lifts, and HVAC systems designed by Maninga Engineering. Managing these disciplines ensured seamless integration and adherence to project timelines,” says Ndlala.

Innovations in plumbing and water management

Steam-to-steam humidifier.

Detailing the integration of plumbing solutions, Ndlala highlights the use of a calorifier for efficient steam utilisation in water heating. “The calorifier, akin to a large geyser, harnesses steam from the hospital’s boilers. The hot water is circulated through a multilayer pipe composed of PE-RT and aluminium, blending the advantages of plastic and metal piping systems. The substantial aluminium layer guarantees strong stability and exceptional mechanical strength.”

Additionally, a backup water tank equipped with a filtration system guarantees continuous water supply, crucial for both operational efficiency and patient care. “By prioritising patient comfort and system reliability, we integrated redundant systems for HVAC units. Each VRF unit was designed with an N+1 redundancy, ensuring uninterrupted operation even in case of unit failure.”