When size matters
Published: 06 October, 2016
Faced with less and less space being available for piped services, how can designers respond. Paul Wightman of Albion Valves shares some ideas — ideas that can also improve the operation and response of those systems.
The modern buildings-services industry has never been under more pressure. There is an ever-growing requirement for engineers and system designers to deliver more — more cost savings, more energy efficiency, more product innovation, more balance and more control —and all this in a built environment with less space and less room for manoeuvre.
Diminishing space for developing combined with the UK’s culture of oversizing is a compounding issue for building engineers. It has never been more important to ensure that a building’s internal systems are designed to make the very best use of space available. As a consequence, specifying equipment designed specifically to save space has become a fundamental element of modern building design.
In new-build and major refurbishments, it is the very early decisions in the design process that determine whether or not the building will run efficiently. The design team must take an integrated approach to all aspects of design to ensure they are fit for purpose, but without creating overcapacity.
Designing systems that optimise space can mean real commercial gains. In a piped system, using fewer larger valves and reduced pipework in risers, not forgetting a reduction in plantroom sizing, when added up can create more commercial retail or living space — so potentially an extra unit in a city apartment block!
At early stages of building design specifiers should consider incorporating products such as Albion’s Monolink, a pre-assembled factory-tested valve arrangement, in which a single unit combines all the features required for a terminal end to meet a distribution pipe; its components include a strainer, bypass valve, balancing valve and drain cock — with no need for assembly on site.
The Monolink is adaptable for a wide range of pipe connections; its H-block structure comprises only four simple union joint connections instead of the standard 22. In addition, the simple and highly compact arrangement minimises the time and space required to connect, allowing much easier installation than the traditional approach and with a much-reduced risk of leakage.
In accordance with BSRIA (Building Services Research & Information Association) requirements, a Monolink also contains all the features required for the process of flushing, reverse flushing and chemical cleaning of heating and cooling systems prior to balancing and setting for standard operation.
Additionally, dynamic balancing allows engineers to control the requirement exactly where the energy demand is — such as in meeting rooms, offices or shop-floor space. Using products such as the PICV (pressure-independent control valve) that will work as a combined commissioning valve, differential-pressure control valve and 2-port motorised control valve (i.e. a 3-in-1 product) means there is the opportunity to save on installed products throughout the system, so there is no need for bigger balancing valves on branches or even bigger balancing valves on risers.
Ultimately, variable-volume systems can help ensure that pipework, valves and fittings are as compact as possible — potentially helping to save space, installation and commissioning costs whilst ensuring performance and reduced energy consumption.
A system based on this design and product specifications can ultimately mean fewer access points or smaller risers and branch core spaces within the building — potentially creating more value-added asset to the property.
In addition to their shopping list of space saving equipment, building engineers need to consider building occupancy, convergence factors and diversity to help prevent needlessly oversizing.
If we consider a commercial building designed to accommodate 2000 people, we should be mindful that the likelihood of all 2000 people being in that same building at the same time is improbable. An informed estimate would speculate that on any one day, a maximum headcount may be 1600 to 1700 people and that is probably oversizing it; yet the building caters for 2000.
If a building has an accurate terminal control, then better comfort catering for higher occupancy levels may be achievable within a given space, so saving on original building size outlay. This a diversity calculation; when more people are in an area than anticipated the flow can be directed to these areas whilst ensuring a base load flow in areas with lower occupation levels to ensure comfortable conditions.
Engineers should also be mindful that there is also greater flexibility within dynamic controls and variable-volume systems; the flexibility lends itself to long-term projects on installation. If we consider a building that is only part-finished when the first phase of tenants move in, dynamic products allow that part of the system to be commissioned and made operational.
As development reaches completion and remaining parts of the building become occupied and the system becomes operational, there is no need for the original phase areas to be revisited or re-commissioned — as would have been necessary with traditional static balancing valves and control products.
In the modern society of overcapacity, informed designers will fabricate a building with diversity in mind and intentionally undersize, so that although the system is built upon a design condition this may be less than 100% capacity and, in many cases, is designed to meet in the region of 70 to 80% of capacity.
Therefore, if everything in the system called for full demand at the same time, the system would be undersized and unable to cope. System control is paramount to ensuring that building performance is accurately adjusted and regulated demand is met 100% of the time without the inefficiencies of oversizing.
Modern dynamic products enable engineers to make extensive changes via the building-management system’s controls to meet demand without having to get their hands dirty with the complex task of altering pipework and valves.
Experienced designers can be confident that occupancy levels and cycles of movement of people and processes are such that in mixed-use development (e.g. retail, office and residential), there is an extensive diversity of loads throughout the day and areas of priority change, so that the system will actually deliver perfectly even if on the surface it appears undersized
So as population and our built environment grows, and paradoxically our space within it diminishes, sizing piped services has a vital role in new building developments. However, it will only deliver the best results when part of a fully integrated design that also considers diversity, convergence, building use and, crucially, the people using it.
Paul Wightman is technical specifications manager with Albion Valves UK.