Retrofitting Legacy Buildings with Modern BMS Technology

Challenges of Retrofitting Legacy Buildings

• Outdated or incompatible equipment
• Lack of documentation or as-built drawings
• Limited electrical or network infrastructure
• Budget constraints
• Minimizing disruption to occupants

Retrofit Strategies

1. Phased Approach

Instead of a full rip-and-replace, implement upgrades in phases:

• Phase 1: Install new supervisory controller and network backbone
• Phase 2: Replace field controllers and sensors
• Phase 3: Upgrade actuators and mechanical equipment

2. Gateway Integration

Use protocol gateways to integrate legacy equipment into modern BMS platforms without replacing functional hardware. For example, a Modbus-to-BACnet gateway allows old Modbus devices to communicate on a modern BACnet network.

3. Wireless Solutions

When running new cabling is impractical, wireless BMS devices offer a cost-effective alternative. Wireless sensors and controllers can be installed quickly with minimal disruption.

ROI of BMS Retrofits

Typical payback periods for BMS retrofits range from 2-5 years through:

• Energy savings (15-30% reduction)
• Reduced maintenance costs
• Extended equipment lifespan
• Increased property value

Retrofit Case Study

A 1980s office building in Manchester was retrofitted with a modern Trend BMS, integrating existing pneumatic actuators via BACnet gateways and adding new wireless sensors. Results:

• 28% reduction in energy costs
• Improved occupant comfort scores
• Project payback in 3.2 years

Planning a retrofit project? Contact Alpha Controls for a feasibility assessment and cost-benefit analysis.