Space and whole life costs are two of the major considerations when selecting commercial condensing boilers. Ryan Kirkwood, Specification Manager for Remeha, evaluates the design options that will make best use of plant room space and optimise boiler lifetime performance
The UK has been set a new, more ambitious target to reduce greenhouse gas emission levels to net zero by 2050. If we are to come anywhere near this goal, we must address the energy efficiency of our existing buildings and their heating systems.
Boilers are at the heart of the heating systems in many commercial buildings, so it’s essential that they operate efficiently. Of course, each building will have its own unique requirements. But many facilities and energy managers are turning to modular boiler designs to meet the tighter environmental requirements, particularly in buildings with fluctuating heat demand.
Forward-thinking manufacturers offer an extensive range of reliable, energy-efficient solutions that enable accurate matching of the actual heat requirement to optimise overall system efficiencies. And if we design for easier future servicing, the lifetime of the boiler will increase still further.
But arguably the two most common design hurdles are space and capital costs. So let’s consider how we can design better with careful boiler selection.
Good boiler selection
As space within plant rooms remains at a premium, the size and design of the boiler will be key, making achieving a high output in a compact footprint a frequent challenge.
Restricted plant room access? The logistics of physically getting the plant into the building – and safely removed at the end of its lifecycle – is another aspect that will need to be addressed.
Fortunately, the arrival of smaller, more lightweight condensing boiler models means that they can be manoeuvred safely into position. Additional features like the inclusion of integral wheels or the ability to disassemble high output boiler into parts again smooths access constraints and associated costs.
But maintenance areas, access space and walkways also need to be calculated when determining boiler selection. With that in mind, let’s evaluate the options.
Modular boiler arrangements can normally be separated into two categories: stacking and floor standing.
Stacking units are designed to be positioned vertically. Typically, a stack of around six to nine modules, usually combined using a vertical header at the rear, will achieve the required output.
A key advantage of vertical stacking style arrangements is their ability to offer a larger heat output in a smaller physical footprint. However, as these arrangements require access on all sides of the plant and pipework arrangement, this generally results in the units being ‘islanded’ in the plant room. The vertical headers will also need careful attention to ensure that the boiler pumps, system pumps and overall hydronics are set up to perform as intended.
Floor standing modular configurations occupy a similar footprint in terms of plant, but access is usually only required at the front. As a result, they can achieve an equally, if not more, compact configuration overall.
When it comes to servicing and maintenance, a multiple floor standing boiler design offers several compelling advantages. Fewer modules will typically be required to match the heat load, so maintenance and servicing costs will be correspondingly lower across the lifecycle of the boilers. And while interconnecting pipework tends to be placed above the units, at a similar height to a vertical-stacking arrangement, the modules are all at the same height, so maintenance can be carried out safely at a lower level.
Regardless of the design, with all modern condensing boilers, quality construction and longevity are critical. The heat exchanger is central to this, as many floor standing boiler arrangements and most vertical stacking systems use aluminium heat exchangers to keep weight down and efficiency up.
Look for boilers with monobloc heat exchangers as they will allow constant thermal expansion across the whole heat exchanger, reducing the need for large joins and improving performance, reliability and lifespan.
Understanding how the connecting pipe kit holds up to the overall job specification, with quality parts, pumps and valves, is also advisable. How flexible and how readily available are the products and accessories? And how easy are the boilers to control?
Efficiency starts with the boilers
When it comes to heating, efficiency arguably starts with the boilers. Modular boiler designs can provide a time saving, energy-efficient solution to meeting heating requirements in restricted plant rooms.
But it’s essential to think carefully about how the plant space is allocated and to ensure good boiler selection. Reliable performance, future ease of maintenance and part replacement are all factors that should be considered from the outset.
And with manufacturers like Remeha helping energy and facilities managers to evaluate the various options, we can achieve the best, most energy-efficient commercial heating solution every time.