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LABORATORIES
MANAGING WORKFLOWS AND PRIORITIES( PART 2)
By Jaco de Wet, ACCM Airconditioning technical manager and a former hospital senior artisan
Inside the day-to-day realities of hospital HVAC maintenance. This is part two of a two-part series. voices
In a facility that never closes, maintenance management relies on rigorous prioritisation. I implemented a triage-based system to categorise issues according to their impact:
• Priority 1( emergency) faults were those with immediate implications for patient safety or clinical operations – for instance, a failure in an operating theatre’ s cooling system or an isolation room’ s extract fan. These incidents demanded an immediate, full-team response.
• Priority 2( urgent) issues, such as a chiller alarm or loss of comfort cooling in a ward, were addressed within hours to prevent escalation.
• Priority 3( routine) tasks, such as non-critical filter changes or minor repairs, were logged and scheduled once higher priorities were stabilised.
The hospital’ s Computer-Aided Facilities Management( CAFM) system underpinned this process. It allowed for transparent tracking, automatic work order generation and audit-ready record keeping. Even during emergencies, preventive maintenance activities were never lost – the system simply rescheduled them, ensuring full compliance continuity.
Team collaboration and cross-training were key, with clear communication, standard operating procedures and delegation. This allowed my team to‘ divide and conquer’, maintaining operational continuity even under pressure.
Pressure regimes were continuously verified. Operating theatres maintained positive pressure to prevent ingress of contaminants, while isolation rooms held negative pressure to contain airborne pathogens. Maintaining these conditions required careful calibration of supply and extract fans, along with consistent maintenance of belts, motors and variable speed drives to sustain design airflow rates.
Jaco de Wet, ACCM technical manager and a former hospital senior artisan.
Temperature and humidity control were equally critical. Different hospital zones required tight environmental control to balance patient comfort, infection prevention and equipment protection. The Building Management System( BMS) monitored these parameters around the clock, while technicians regularly calibrated sensors to ensure accurate feedback to the control systems.
All images supplied by ACCM
INFECTION CONTROL AS A CORE FUNCTION At the centre of all hospital HVAC maintenance lies infection control. The air filtration systems were designed as multi-stage defenses, starting with panel pre-filters, progressing through bag or compact cassette filters, and culminating in HEPA filters for ultra-clean environments such as operating theatres and isolation rooms.
Filter changes followed strict schedules determined by both time and performance. Primary filters were replaced every two weeks, compact cassette filters annually, and HEPA filters every five years or earlier if particle counts fell outside acceptable limits. Pressure drop readings from Magnehelic gauges guided interim changes, ensuring filters never operated beyond their effective lifespan. After major filter replacements, integrity testing such as DOP or particle counting was conducted to confirm seal integrity.
RACA Journal I March 2026
Chilled and hot water air handling unit. Primary fresh air filters and behind them are the secondary filters for the fresh air supply, which is one of two fresh air supply systems.
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