The Hollins High School, Accrington
Low-Carbon Heating Retrofit and Energy Efficiency UpgradeVital Synergy partnered with The Hollins High School, an 11–16 secondary academy in Accrington, to deliver a comprehensive sustainable heating retrofit. The project replaced an outdated boiler system with state-of-the-art air source heat pumps and modern controls, dramatically reducing energy use and carbon emissions while improving comfort and compliance. Meticulous design, careful project execution and innovative technology together delivered up to 40% energy savings and modernised the school's heating infrastructure.
Client Overview
A three-storey, 11–16 secondary academy of approximately 5,500m² in Accrington, Lancashire. The school's existing infrastructure relied on three ageing gas-fired boilers that were inefficient, carbon-intensive and increasingly unreliable, prompting a major decarbonisation and energy efficiency project to upgrade its heating system.
Key project drivers were to replace fossil-fuel heating with a low-carbon solution and future-proof the building, achieve energy efficiency improvements to control rising costs, ensure regulatory compliance with improved EPC ratings and government climate targets, and enhance classroom comfort and heating reliability for students and staff.
A comprehensive on-site survey of the existing heating plant, distribution networks and building fabric mapped each zone's heating requirements. Detailed heat loss calculations and load analysis sized the new equipment precisely, with multiple low-carbon options evaluated for efficiency, capacity, feasibility and long-term sustainability.
Five large Clade air source heat pump units, totalling 960kW, replaced the gas boilers. Four units meet full heating demand while a fifth provides standby redundancy, supplying the building's entire heating needs and contributing to hot water generation.
New insulated distribution piping and low-temperature heat emitters were sized for efficiency. Optimising for lower water temperatures reduces heat losses, maximises the heat pumps' Coefficient of Performance and improves occupant comfort.
A modern Loxone Building Management System manages heating schedules, thermal zones and heat pump performance, enabling automated setback during unoccupied periods and real-time remote monitoring. Salus smart thermostatic controls allow local classroom temperature adjustment.
Key Outcomes and Benefits
Five Clade air source heat pumps now supply the school's entire heating demand and contribute to hot water generation, with built-in standby redundancy for resilience.
Annual heating energy consumption is down by up to 40% compared with the old gas-fired system, lowering operational energy costs across the academy.
An estimated 175 tonnes of CO₂ is cut annually by replacing fossil-fuel boilers with low-carbon air source heat pump technology.
The new system delivers consistent, comfortable low-temperature heating across the entire three-storey secondary school.
Four units meet full heating demand year-round, with a fifth providing standby redundancy to safeguard reliability during peak winter loads.
The retrofit improved the school's EPC rating and aligns with Net Zero carbon goals and updated building regulations for the education sector.
Project Detail
A rigorous health and safety plan governed every stage of the retrofit, from pre-construction planning through to final handover and commissioning. Frequent coordination meetings with the school's facilities team and the LET Education Trust kept all parties informed of progress and upcoming works.
Major works were scheduled during school holiday periods, including the summer break, to avoid disrupting teaching, with commissioning and testing completed before reoccupation.
Design Approach and Engineering Strategy
Vital Synergy's design team used a rigorous, data-driven methodology, beginning with a comprehensive on-site survey of the existing heating plant, distribution networks and building fabric. The survey mapped each zone's heating requirements and engaged the school's facilities managers directly, building an understanding of the legacy system's limitations and site constraints, including space restrictions and known asbestos-containing materials in the older plant areas.
Survey data fed detailed heat loss calculations and load analysis, sizing the new equipment precisely and confirming the building's thermal demand. Multiple low-carbon options were evaluated for efficiency, capacity, feasibility and compliance with regulatory standards before air source heat pumps were selected as the optimal solution, offering the best balance of energy efficiency and carbon reduction while fully meeting heating needs even in cold weather.
Compliance and Safety
Hazardous materials, including asbestos-containing paint identified in the old boiler room, were safely abated by certified specialists ahead of the main works. Strict protocols governed core drilling and working at height throughout the plant replacement, with site segregation maintained around live teaching areas at all times.
Thorough testing and commissioning of equipment and controls followed installation, alongside facility-manager training on the new Loxone BMS. A complete Operation and Maintenance manual and support package was handed over to the school on practical completion.
Programme and Delivery
Detailed surveys and heat load analyses carried out up front enabled accurate equipment sizing, ensuring the new system meets comfort needs efficiently and adheres to regulatory standards. Executing the major retrofit work during school holidays and off-hours allowed construction to proceed without affecting learning, an approach now informing Vital Synergy's model for upgrades in occupied schools.
Upgrading the whole heating ecosystem together, generation, distribution and controls, proved crucial to unlocking the full performance of the heat pump technology. New low-temperature emitters and smart Salus controls give the system a dynamic response to changing conditions, while the standby heat pump unit provides a significant uplift in reliability over the old boiler arrangement.
Legacy for Education Sustainability
Beyond the energy and carbon savings, the retrofit improved the school's EPC rating and brought the heating installation into line with current building regulations and educational facility standards. The completed retrofit stands as a flagship example for sustainable school upgrades, demonstrating that large, occupied educational buildings can be cost-effectively transitioned away from fossil fuels without compromising daily operations.
The lessons learned at Hollins, on thorough upfront survey work, phased delivery around the school calendar, and treating the heating system as a single integrated ecosystem, are now informing Vital Synergy's approach to retrofit projects across the education sector.
Moving away from gas boilers to air source heat pumps felt like a big step, but Vital Synergy made the transition smooth from start to finish. We're already seeing the benefit in our energy use, and the new Loxone controls give us much better oversight.
Estates Manager · The Hollins High School, Accrington
