Case Studies

Harris Primary School THERMOBOIL Installation

  • Client

    Lancashire County Council
  • Location

    Harris Primary School, Fulwood, Lancashire
  • Sector

    Boiler Installation
  • Requirements

    To replace outdated domestic hot water cylinders with a new, highly efficient thermodynamic unit and remove the existing cold water storage tank from the school’s attic.
  • Objective

    To make the school more energy efficient and, in doing so, reduce the school’s CO2 emissions and energy bills.

New Thermodynamic Unit


Lancashire County Council approached SC Horsfield Building Services Engineers to update the hot water system at Harris Primary School in Fulwood, near Preston, in order to improve the energy efficiency of the school, thereby reducing energy costs and emissions.

The focus of the works was the hot water supply to the school’s kitchen, which was using a tank-fed, domestic hot water storage cylinder. The 2m x 0.8m cylinder used two 6KW electric immersions to provide the hot water required for three large sinks, one hand basin, and one industrial dishwasher.

As part of our initial inspection, we installed meters on the TCWS to the cylinder and on the three phase electrical supply, allowing us to monitor the energy consumption over a two week period. This would enable us to show any improvements following the installation of the new, highly efficient thermodynamic unit.

We recommended the installation of a THERMBOIL unit, a new concept in thermodynamic compact systems. This innovative water heater, which includes a heat pump system with solar gain and a water tank, has been designed to capture the ambient solar energy to heat water efficiently, thereby reducing energy consumption compared to conventional systems.

In this instance, we installed the THERMBOIL RH (Rapid Heating) unit. The THERMBOIL RH uses panels which can be placed inside or outside the establishment, meaning they can capture both solar and environmental energy. Due to its greater thermodynamic power, heating time is much quicker, ideal for Harris Primary School’s demands for large volumes of direct hot water.

Other advantages of the THERMBOIL RH unit include: two compressors connected to two independent circuits, maximising efficiency; shorter recovery time; an auxiliary electrical system; and an anti-legionella system. The unit has a high-quality finish, an appealing design, is quiet and does not require an annual inspection or sterilising, saving the school around £750 per year.


The old cylinder and cold water storage tank were decommissioned at 3pm on Friday 8th July and within 48 hours the new 500 litre THERMBOIL RH unit was displaying a water temperature of 60°C.

Meters installed on the MCWS to the cylinder and on the single phase electrical supply were monitored over the course of a typical week. Compared to the reading from the original system, the results were quite staggering.

  • Energy bills will reduce around 60% each year
  • CO2 emissions will reduce by around 2500kg each year
  • The school’s Energy Performance Certificate is currently graded D. When the school is reassessed, we are hopeful that the reduced CO2 emissions will lead to the EPC being graded to a C

The old water tanks have been decommissioned, resulting in improved water pressure to the kitchen, for both hot and cold water.

The impact of the school on the environment has been vastly improved and, what’s more, the school should see a Return on Investment in just two years.

Harris Primary School is now a much greener school!

Call 01772 654402 to find out how Horsfield can help your business.

Energy bills
reduced by 60%

CO2 emissions reduced by approx. 2500kg