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Marflow Hydronics has launched the Remote Commissioning concept, an innovative approach designed to simplify the installation and commissioning of fan coil and chilled beam systems. It is able to significantly reduce the cost of installing such systems, while also ensuring they operate at optimum efficiency.
One element of the concept is the use of addressable pressure independent 2-port valves from Belimo, linked to a BMS or local controller. This enables valves to be adjusted remotely from a central PC or other control device without the need for an engineer to enter the ceiling void. Consequently, as well as speeding up commissioning, it also enables quick and easy re-configuration of systems – to accommodate layout changes within the space, for example.
“Most people don’t realise that centralised, remote control, which is widely used in other building services systems, can be applied to chilled and hot water systems,” explained Marflow’s Martin Lowe. “However, the Remote Commissioning approach is about more than new valve technologies. It is designed to give the specifier and installer complete control of the project from start to finish. As such it also incorporates centralised management of valve information and hydronic performance data, advanced pre-fabrication techniques and innovative commissioning processes using Marflow’s single station balancing method.
“At its heart is a recognition that design, installation and commissioning practices in many projects have failed to keep pace with key developments in the industry. These developments include the growth of design and build, skills shortages and the increased use of multi-national labour forces, and the opportunities provided by modern valve technologies.
“As a result, this outdated approach is failing to deliver the best result for the contractor and the end client in many projects,” he continued. “Our approach seeks to rectify the current fragmented approach to system design by creating a single system from one source; a complete process that equals a complete solution,” he added.
The system can be divided into several stages:
Smarter design
Attention to detail from the start of the project and anticipating problems before they occur can optimise the use of site labour, compensate for inherent skills shortages or inexperienced operatives and minimise the risk of installation errors.
Management of information
Many problems arise from poor communications between members of the project team The Marflow system brings all valve information and hydronic performance data into a single, purpose-designed spreadsheet package that is continually updated, with any changes being distributed to all relevant parties.
Innovative installation
Rather than seeing pre-fabrication as simply a way of transferring site work to another location, the Marflow approach takes full advantage of the benefits of pre-fabrication. These include use of innovative valve assemblies, location of all valves for each zone in a single location that also contains information about the system, facilitation of single station balancing (see below), pre-insulation of the manifold box and use of pre-insulated, flexible pipe.
Reducing installation errors
Pre-fabricated assemblies are supplied complete with all components, using labelling and colour coding of connections to ensure correct installation. Full instructions are provided, using diagrams so that language is not an issue.
Single Station Balancing (SSB)
Unlike proportional balancing, which is laborious and time consuming, the SSB method uses a subtraction technique to identify problem valves. This is based on knowing the design flow rates for each individual valve and, therefore, the total flow rate for that fan coil group.
Assuming all the valves are functioning correctly, isolating each valve will have a predictable effect on the total flow rate for the remaining valves. Where an unexpected result is observed it is a simple matter of elimination to quickly identify the valve that causes this, enabling the commissioning engineer to home in on the problem area.
SSB is discussed in more detail in the background notes
Innovative valves and controls
The Remote Commissioning concept takes full advantage of the functionality of Belimo’s pressure independent two port control valve, linked to a BMS fan coil or chilled beam controller, and an actuator that can be set from a remote location to the required position to give design flow rates. This allows only two valve sizes and four valve configurations of flow and return to be used in achieving the design performance.
The BMS controller, housed in its own case, can be wired to the actuator via pluggable leads and sockets within the assembly. A power plug socket is provided for mains power to the controller and to allow switched power to the fan on the fan coil unit. A plugged cable is also provided from the controller to the fan coil unit supplying power and the temperature sensor. The communication cable to the BMS is also a pluggable connection.
In summary, the Marflow system is designed to achieve the following: