Advanced Energy Optimisation
Optimising mechanical and electrical plant to reduce cost without compromising compliance or comfort. Engineering-led efficiency improvement.
Beyond Basic Energy Efficiency
Most commercial buildings have exhausted obvious efficiency measures—LED lighting, insulation, basic time scheduling. Yet HVAC systems continue to waste 20-40% of energy through poor controls, simultaneous heating/cooling, excessive outside air intake, and suboptimal plant sequencing.
Advanced energy optimisation addresses these complex inefficiencies through controls tuning, plant performance testing, and model-based optimisation strategies. This work requires chartered engineering expertise and deep HVAC knowledge—it is not achievable through generic energy assessments or facility management alone.
Optimisation Strategies
AHU Optimisation
Testing actual airflow rates against design intent, reducing excessive ventilation rates, implementing demand-controlled ventilation based on CO₂ or occupancy sensors, and eliminating simultaneous heating/cooling. Many AHUs deliver 150-200% of required airflow—reducing fan duty cuts energy consumption by 30-50% without compromising IAQ.
Cooling Plant Sequencing
Optimising chiller staging and condenser water temperature reset to improve part-load efficiency. Poor sequencing causes multiple chillers to operate at low part-load (inefficient), or single chillers to operate at high load (reduced reliability). Advanced sequencing matches chiller operation to actual cooling demand, reducing kWh/ton by 15-30%.
Night Purge Strategies
Exploiting cool night air to pre-cool buildings before occupancy, reducing daytime chiller runtime. Night purge is particularly effective for high thermal mass buildings in temperate climates. Automated control based on outdoor/indoor temperature differentials maximises free cooling without manual intervention.
Deadband Tuning
Increasing temperature control deadbands (the range within which heating/cooling systems do not operate) reduces unnecessary plant cycling and simultaneous operation. Widening deadbands from ±1°C to ±2°C can reduce HVAC energy consumption by 10-20% without affecting occupant comfort. Requires careful commissioning to avoid comfort complaints.
Heating System Optimisation
Implementing weather compensation (reducing flow temperatures during mild weather), optimising boiler staging for part-load efficiency, and reducing unnecessary system temperatures. Many heating systems operate at fixed high temperatures year-round—weather compensation reduces gas consumption by 15-25% without capital investment.
Variable Speed Drive (VSD) Control
Optimising VSD setpoints for pumps and fans to match actual demand. Existing VSDs often operate at fixed speeds or poorly tuned control loops—proper commissioning reduces motor energy by 20-50%. Pressure differential control, trim & respond algorithms, and night setback further improve VSD efficiency.
Real-World Savings Examples
Office Building, London (15,000m²)
Baseline: 180 kWh/m²/yr electricity consumption
Interventions: AHU airflow reduction, chiller sequencing optimisation, deadband widening
Result: 28% reduction (50 kWh/m²/yr), £42,000 annual saving, 12-month payback
Data Centre, Manchester (5,000m²)
Baseline: PUE 1.8 (Power Usage Effectiveness)
Interventions: Free cooling maximisation, hot aisle containment, raised floor optimisation
Result: PUE reduced to 1.3, £180,000 annual saving, 18-month payback
Retail Park, Birmingham (25,000m²)
Baseline: £120,000 annual gas consumption
Interventions: Weather compensation, boiler sequencing, zone control improvements
Result: 22% gas reduction, £26,000 annual saving, controls-only intervention (zero capex)
Sustaining Performance
Optimised systems require ongoing monitoring to sustain savings. Controls drift occurs through setpoint overrides, schedule changes, and sensor degradation. Buildings without performance monitoring typically lose 30-50% of initial savings within 2-3 years.
We recommend annual recommissioning or continuous monitoring platforms (BMS-integrated analytics or cloud IoT systems) to detect performance degradation and trigger corrective action. Continuous monitoring costs £500-2,000/year but protects £10,000-50,000+ annual savings—highly cost-effective insurance against performance erosion.
Related Services
Request Optimisation Assessment
Our chartered engineers conduct advanced energy optimisation for commercial, industrial, and public sector estates. We provide guaranteed savings contracts with performance monitoring and annual recommissioning. Contact us for a site-specific optimisation proposal.
Request Optimisation Assessment