Air Handling Systems – Government Buildings

BJF Group was appointed to replace an end-of-life air handling unit (AHU) within a government building. The project delivered a modern, energy-efficient ventilation solution that significantly improved indoor air quality while ensuring the facility remained fully operational throughout.

Client and Scope

Drawing on extensive experience within secure and operational public environments, BJF Group worked closely with the client to design and implement a delivery strategy tailored to the building’s restricted access and continuous occupation. The scope covered the removal of the existing AHU, installation of a new modular system, and reinstatement of all mechanical and electrical services.

• Safe removal and compliant disposal of the existing AHU from a restricted basement plantroom
• Delivery and installation of a new modular AHU in sectional components to navigate tight access routes
• Reinstatement of mechanical services, including LTHW, chilled water, and ventilation ductwork
• Installation of new electrical power supplies and full BMS integration
• Fire alarm interface works, including cause and effect configuration
• Testing, flushing, commissioning, and performance verification of all associated services
• Provision of complete O&M documentation and as installed records

Project Goals

The scheme supported a wider initiative to enhance environmental performance, energy efficiency, and long term building reliability. This project focused on modernising key ventilation infrastructure while ensuring uninterrupted building function.

• Reduce energy consumption and cost.
• Improving indoor air quality and occupant comfort
• Reducing long-term maintenance requirements.

Execution & Results

Delivery required a highly coordinated approach due to restricted access and confined basement working areas. BJF carefully dismantled the existing AHU using specialist lift and shift techniques to navigate narrow corridors and stairwells. Throughout the works, strict noise, dust, and safety controls were implemented to ensure building operations remained unaffected.

Key elements of the delivery included:

• Specialist removal of the existing AHU, using lift and shift methods to move components through restricted corridors and stairwells
• Modular delivery of the new AHU, enabling safe manoeuvring through tight access routes and efficient on-site assembly
• Full reinstatement of M&E services, including chilled & heating water pipework, ductwork, BMS cabling, and power supplies.
• Implementation of strict environmental and safety controls, ensuring zero disruption to staff and daily building activities
• Commissioning, including functional testing, airflow verification, controls optimisation and full fire alarm cause and effect integration

Lessons Learned

• Early logistical planning is essential when working within confined or access-restricted environments
• Clear communication with building stakeholders minimises disruption and improves delivery efficiency
• Modular plant solutions greatly simplify installation where access is limited
• Programme flexibility is vital when interfacing with legacy systems and addressing unforeseen conditions

Summary

BJF Group successfully delivered a complex AHU replacement within a constrained operational environment while maintaining full building continuity. The project highlights the importance of precise logistical planning, clear communication, and the advantages of modular equipment. The upgraded ventilation system now provides improved efficiency, reliability, and comfort for building users.