Upgraded heating cuts fuel bills by 80%
At the heart of an 80% improvement in the energy consumption of the heating system at a youth centre in Devon are Honeywell CM67 programmable controllers.
Gas bills for a youth centre in Devon have been cut by 80% following an upgrade of the heating systems, including the installation of Honeywell controls. The savings amount to nearly £300 a year, and the electricity bill has also been reduced. Alan Gregory of The Stove Shop and consultant Arthur Richards of Advanced Hot Water and Heating Design, introduced several features to make the system serving Kingsteignton Youth Centre highly responsive, efficient and cost-effective to run. The most important plumbing improvement was to add a new feed and return from the boiler room to manifolds in the heating cupboard on the other side of the building. All seven Honeywell CM67 controllers can switch the boilers, with water flow controlled by Honeywell motorised valves. System efficiency was improved by replacing a single large boiler with two smaller Quantum 80 boilers of 23 kW each. Their combined output is the maximum system demand. Underfloor heating circuits are supplied by a via a Honeywell 28 mm thermostatic mixing valve to blend flow water from the boilers with return water from the system to deliver a constant temperature to the heating circuits. Another detail to enhance efficiency is the automatic bypass circuit, to prevent the boilers cycling on and off. The sports hall is heated by an air-handling unit on the roof. It was previously controlled by a timer that passed hot water unnecessarily around a loop when there was no call for heat. Honeywell valves now interlock with the boiler to switch it off when heat is not needed. Control is provided by a CM67 programmable controller for each of the seven heating zones. Sarah Diaz, centre development manager, says, ‘It is very simple to set individual times and temperatures for each zone. I program the set temperature in each zone to change automatically at various times during the day and from day to day, so rooms are heated to the appropriate temperature for each activity. It is also easy to over-ride a set temperature if necessary. Each controller is hard-wired to the zone it controls. Sensors cannot be adjusted, to prevent tampering. The controllers incorporate optimum start as a further energy-saving feature. Despite the previously high gas bills, rooms were often cold. The improved comfort levels have made a huge difference. ‘The centre has established itself a vital place at the heart of the local community,’ Says Sarah Diaz.