Commercial heating


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Mind the gap W


hile good energy management is central to reducing demand, the heating and hot water system has long been identified as a natural target for efficiency improvement. As one of the largest users of energy in a building, the performance of this service not only influences the building’s operational costs and environment impact but can impact on occupant well-being and productivity.


But as designs grow more complex and hybrid systems are increasingly applied to reduce emissions associated with heating, there’s a greater likelihood of a gap between the design and its as- built performance. This leads to reports of high efficiency condensing boilers not achieving the anticipated performance and savings, or CHP units that waste heat in favour of generating electricity.


Stick to the spec If the goal is to use the energy input more efficiently, how, then, to avoid


Stick to the spec


poor system performance and unnecessary energy waste? The starting point, particularly on more complicated projects, is surely for consultants, contractors and manufacturers to unite to protect the original specification. The most important part of the project, the specification, is the result of lengthy research and careful consideration, with the specified equipment frequently helping define the heating solution. As a result, where the specification document details precise equipment and/or manufacturers, any divergence runs the risk of impacting on the overall efficiency and performance of the system. A simple example might be a CHP and boiler hybrid solution where a particular boiler has been specified for its high temperature secondary return feature to optimise operation. Replacing the boiler with a different make or model might seem a small change, but without this feature the service could be compromised.


Avoid cost cutting Avoid cost cutting


Sticking to the specification helps ensure not only longevity and quality, but also safety, minimising the risk of issues further down the line. Indeed, one of the key recommendations to come out of the Dame Judith Hackitt’s Independent Review of Building Regulations and Fire Safety was for a clearer, more transparent and more effective specification process to put an end to cost-cutting compromises. That being so, why, then, are changes still made to the recommended equipment? The frequent cause is value engineering (VE). The original aim of VE was to improve the value of a design through cost, all the while maintaining its integrity and function. But when it comes to heating and hot water, VE is typically reduced to a cost-cutting tool that removes rather than adds any project value. What’s more, VE brings time implications to the project delivery, with reviews and changes to specification and design making the process less rather than more efficient. All too often, the unfortunate result is a system – and building – that fails to deliver in terms of both performance and efficiency and a customer


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First, manufacturers should ensure the product information provided is clear and up to date. This will avoid any ambiguity surrounding heating ment and their achievable efficiencies.


r and up to date. This will avoid any ambiguity surrounding heating equipment and their achievable efficiencies.


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Next, good manufacturers should be considered as a valuable technical resource for specifiers and contractors alike. Involving experienced manufacturers at the early stages can help save time and money as, with their in-depth knowledge of their products, they can advise on how maximise their efficiency. As they will often have seen a similar scenario before – and its outcome – they will be able to provide helpful exemplar designs. Early engagement would also enable the designer to develop a robust physical specification alongside the design philosophy rather than ad hoc.


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oney as, with their in-depth knowledge of their products, they can ise on how maximise their efficiency. As they will often have seen lar scenario before – and its outcome – they will be able to provide


A further pragmatic solution might be for consultants and contractors to consider providing manufacturers with a budget for the project at the outset. This would eliminate the need for any cost cutting at a later stage as the system could be designed with both the project and budget requirements in mind.


Whole life costing


Switching to a whole life costing approach would also provide the customer with a more accurate evaluation of the equipment that includes not only the initial capital costs but reflects the ease of installation, maintenance and servicing. The warranty should also be assessed as it will indicate the confidence of a manufacturer in the reliability of their products’ ability to deliver high quality performance time after time.


to deliver in terms of both performance and efficiency and a customer fails to get the promised outcome.


Finally, we should consider a move away from the term ‘equal or approved’ to ‘equal AND approved’ to ensure that the performance delivered is as designed, if not better. If we return to our previous example of boilers, this replacement of just one word would make everyone winners. It would give the designer greater confidence in the quality of the products, plus the ongoing peace of mind that the specification will be met. The customer or end user specification would be assured of achieving the required high quality, energy-efficient outcome. Installers and FM providers would benefit from boilers that are easier to work with and hassle free in the years ahead.


Even on more straightforward, generic projects, where cost may


With more stringent energy performance requirements set to be introduced for non-domestic buildings, we need to put an end to any processes that cause unnecessary energy waste. With greater collaboration and adherence to best practice specification and engineering, we can be confident of achieving more energy-efficient heating and hot water provision in every building, every time.


www.heatingandventilating.net


With calls to reduce energy waste in commercial buildings, eliminating energy performance gaps between the heating system as designed and as built should be a priority, says Baxi specification director Tom Murray


be a major consideration, the unwavering focus must always be on delivering the best possible solution for the customer. Take a boiler replacement project. We are all familiar with the phrase ‘equal or approved’ in performance specifications. Yet while different boiler makes and models might appear similar on paper in terms of efficiencies and emissions, how many products are actually ‘like for like’ in reality? The truth is that they often differ greatly when it comes to quality and reliability.


Steps to best practice


Fortunately, there are a number of practical steps that we can take to ensure best practice and end unnecessary energy waste.


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