Our notoriously unpredictable climate makes the winter months the most challenging time of year for UK heating engineers to maintain a comfortable, healthy climate for people to live and work in.
Heating systems in public spaces such as office blocks, retail outlets, hospitals and schools come under stress, with multiple variants compromising the smooth running of a system including the movement of people, the use of electronic appliances, open windows and doors and individuals tampering with thermostatic controls.
This combination contributes to an environment that is either too hot or too cold and that often does not have enough ventilation, as well as causing inefficiencies in the heating system.
In a work environment in-effective temperature control can have a knock-on effect of poor performance, and overzealous use of heating as well as icy blasts from CHW units can be equally troublesome and uncomfortable for a workforce.
To promote a comfortable environment and individuals’ wellbeing, heating engineers are advised to focus on balance and control. The correct design and implementation of central heating and CHW systems will provide the right balance for optimum comfort levels and effective temperature control year-round.
The “T set” is the desired room temperature required exactly at all times of year and throughout the day. With poor balance and control the system swings become too great, causing extreme temperatures in our environment and energy wastage.
A properly balanced, variable-volume system can be achieved with the correct set of dynamic balancing and control valves – these ensure the correct distribution of flow throughout the whole system irrespective of any pressure changes, or the partial system load that will inevitably occur for the majority of a building’s operational life.
If the correct balancing is not established, it will result in unequal distribution of the flow and a surplus effect in some terminals while not enough in others, consequently lowering the quality or comfort control.
One solution is the use of differential pressure control valves (DPCVs), which has proved to be extremely efficient in helping to stabilise the temperature in heating systems.
A DPCV is set to maintain a steady differential pressure, under dynamic balancing conditions, which ensures flow cannot exceed a desired rate. This helps reduce both energy consumption and the risk of noisy, vibrating pipes while also simplifying the commissioning process.
Another option are thermostatic radiator valves, which are self-regulating and control the water that enters a radiator, and are ultimately able to help maintain a desired room temperature. They come with tamper-proof temperature settings and are ideal for commercial buildings.
Similarly, in installations that require balance to be controlled in a specific location – for example, one point of delivery to a room – pressure-independent control balancing valves can be used. These are particularly effective on four-pipe HTG and CHW terminal units – for example, fan coil units and air-handling units – that can overheat a space or emit chilly blasts when over-circulating chilled water in the system.
Paul Wightman is technical specifications manager at Albion Valves