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Case Studies

Harris Primary School Thermoboil Installation

  • Client

    Lancashire County Council
  • Location

  • Sector

    Local Authority
  • Requirements

    To update the school's domestic hot water system.
  • Objective

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

002-1464-tb500The focus of the works was a tank-fed, domestic hot water storage cylinder supplying hot water to the school’s kitchen. The 2m x 0.8m cylinder used two 6KW electric immersion heaters to provide the hot water required for three large sinks, one hand basin, and one industrial dishwasher.

As part of our initial inspection, meters were installed on the TCWS (tank cold-water supply) to the cylinder and on the 3-phase electrical supply to the immersion heaters. The meters would enable us to measure and record energy/water consumption data over a 2-week period prior to decommissioning and removal of the old cylinder.

In this instance, we recommended and installed a Thermoboil TB 500E; this innovative water heater is a new concept in thermodynamic compact systems and combines a heat pump system and a water cylinder in one unit, and the thermodynamic collector panels were placed inside the tank space to capture the ambient environmental energy from the kitchen next door. Due to its greater thermodynamic power, heating time is much quicker, and ideal to meet Harris Primary School’s demands for large volumes of direct hot water.

Other advantages of the Thermoboil 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, and is quiet.

Decommissioning of the cold storage tank in the loft space means that the school does not require an annual inspection, or sterilising regime, 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 Thermoboil unit was displaying a water temperature of 60°C.

Meters installed on the MCWS (mains cold-water supply) to the cylinder and on the 1-phase electrical supply were monitored over the course of a typical school week, then compared to the reading from the original system, the results were quite impressive.

  • 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, and the new mains-fed cylinder has improved the kitchen water pressure 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