Heating Control Systems: How they Work and Their Impact on Energy Performance Rating
It stands to reason that houses with modern heating control systems have a better energy rating than houses without a heating control system. But how is the energy performance of a house affected by this and what does the heating control system consist of? This article seeks to answer the questions.
Benefits of Heating Control Systems
The benefits of a heating control system are:
• The ability to control heating and hot water; turning them on and off automatically
• To save money on heating bills by installing and using controls efficiently
• To adjust the temperatures in each room individually without having to heat the whole house to the same temperature.
Components of a heating control system
Whatever type of central heating system the owner has, be it gas or oil-fired, a full set of controls are needed. These are a timer or programmer, a thermostat for the room and thermostatic radiator valves (TRVs).
The programmer will switch off the heating automatically when the owner is not at home and when it is unnecessary, i.e. when they are asleep. A programmer allows the owner to set an “on” period and “off” period. Most models will let the owner set the central heating and domestic hot water to go on and off at different times. Note that these serve different purposes; central heating water is needed by radiators whereas domestic hot water is used by the kitchen and bathroom. The programmer can be set to allow the owner to have domestic hot water instantly and whenever required.
Generally, most households want different rooms to be heated at different times of the day. The bed-room and bathroom would be heated in the morning, the kitchen and living room in the evening, for instance. The “zone control” option on the programmer allows this by having different heating circuits for different parts of the house; there is a separate programmer for each circuit. If a new heating sys-tem is being fitted, zone control is recommended because it helps to reduce heating costs. For example, in a two storey house, two zones may be required, one for each level of the house.
The thermostat is a preventative measure, stopping the house from getting warmer than necessary. Thermostats turn the heating on until the set temperature is reached and then turn the heating off until the temperature drops. It is imperative that they are placed in spots where there is a free flow of air, i.e. not blocked by curtains or furniture and not placed near heat sources. This is because they need a free flow of air to sense the temperature. The room thermostat should be set between 18 and 21 degrees.
Thermostatic radiator valves (TRVs)
The purpose of TRVs is to reduce the flow of water through the radiator. They do not control the boil-er. TRVs are fitted to radiators and when the room temperature goes above a certain set temperature, the water flow is reduced. The owner sets the level for the room; a lower setting saves energy and money.
Impact on Energy Performance Certificate
The impact on the Energy Performance Certificate of having a heating control system equates to having an additional 10 to 15 points in the energy rating compared to a property without a heating control system which is similar in size, style and age.