SPONSORED BY Big hitte Big hitte g O ver the last year or so, and engineering


manufacturers havemade vast strides in the design g of modern boilers,


particularly the latest light commercial wall hung units. Advances in boiler technology have resulted in improved levels of performance, especially in key components, such as the heat exchanger, pump and controls,which have key roles to play inmaximising reliability and efficiency.


(includingATA


The latest boil ers to enter the market AT


TAGCommercial’s newXL-F


and XL-Wmodels) have taken things a step further by integrating all themain componentswithin the boiler itself, significantly redu


costs and the space required.Plus, bymaking all these key components accessible from t installation, ongo maintenance is m


reduces engineers’ time on site. Of all the internal components, the


relationship between the heat exchanger and the pump is crucial in ensuring energy efficiency


y remains as high as


possible. It is recognised throughout the industry thatmodern heat exchanger technology has evolved considerably during the last 10 years or so,with an increased abil lity to maximise heat transfer, while m


maintaining reliability.


This can be attributed to the vastmajority ofmodern heat exchangers beingmade fromstainless steel and comprising multiple, pp, specially


y engineered pipes, g p p ,


ensuring the capacity to achieve high levels of heat transference and condensation –while preventing contamination.


properties ensur further advantag As amaterial,


ring it remains smooth, es,due to its unique stainless steel offers


the front of the boiler, oing servicing and made easier


The continued evolutio has resulted in the lat way in terms of efficie Paul Martin, national s Commercial, looks at t


despite th ers in light m g


ency and performance. est units leading the on of boiler design


in technology and des ign on modern light commercial boilers


he presence of sulphuric and


nitric acid in thewater (created fromflue gas condensate). In fact, stainless steel can neutralise any such corrosive effect and sustain a longer lasting,higher level of operatio


to alternative heat exchanger materials. volatility of the operational ents heat exchangers are


systems, t exposed t environm Given the


o as part of commercial heating this is a significant plus point.


It is the heat exchanger’s job to


transfer the thermal energy generated from burn


m ning gas into the system water.r.


This iswhere themodulating circulation pump comes into play.


ucing installation time, r, which also


In high efficiency boilers, the pump ensures thewater inside the heat exchanger remains turbulent; this agitates thewater flow, so there is no insulating barrier between the heated water and thewall of the heat exchanger, resulting in a rapid transfer of heat. Turbulent flowoccurswhen the


velocity in thewater channel is high – a factor tha Because t


at is determined by the pump. the pump is moving water


around inside a small, closed system (between the boiler and the lowloss header or


r heat exchanger depending


of the application), it does not expend a lot of en


nergy, so is very efficient.


Plus, the turbulent flowof thewater helps preserve the lifespan of the heat exchanger itself by reducing the build-up of any precipitates on the heat transfer s


surface. the fluid m


Aturbulent flowsees the particles in move in random and chaotic


directions,unlike a laminar flow,where particles a


are flowing in parallel lines.


This turbulence ensures a higher heat transfer coefficient, so not only does energy efficiency remain as high as possible, the boiler also reaches and


ma onal efficiency when compared


Th bu an he a t


e boilers are able to communicate ilt-in, intelligent modulating pumps. d XL-F ranges actually have two at exchanger models in our XL-W urbulent flowofwater, the dual Given the importance of creating aintains set-point temperature quicker.


with the pumps and receive accurate feedback on their operational status. The pumps also continually monitor the flowrate, recognise any blockages and pre


event damage, as well as ensuring optimum performance and efficiency. This links us back to the heat


exchanger;when these components contain specially designed hydraulic chambers,water turbulence is optimised to ensure maximum heat transfer,whilemaintaining the lowest possible pressure drop.With some models (including those referenced earlier) nowcomprising dual heat exchangers operating independently fromone another, they are effectively working as an internal cascade. As a result, if one heat exchanger requires replacement or repair, the other can remain fully operational, so a system will not completely lose heat during ess


e a 180kW W maximum output and 18kW kW


minimumoutput of has awider – and therefore superior –modulation ratio of 10:1. Indeed, boilers are considere


ed to


have a ‘good’modulation ratiowhen their minimumoutput is one fifth or sixth of the maximum achievable output. Energy efficiency is further


enhanced by controllability,with built-in cascade boiler controls now commonplace in newcommercial units. Incorporating these as par the main boiler removes the need for additional, external controls, although it is important to consider enhanced connectivity options, so that boilers can be easily integrated with building management syste


d t of


ems


sential maintenance or servicing. Sowhat else needs to be considered when selecting amodern light commercial boiler?When it comes to saving energy, modulation is an important factor. Boilerswithwide modulation ratios not only improve efficiency, they also reducewear and tear on components. This ratio is a boiler’s ability to reduce its maximum output to itsminimumoutput; the wider themodulation range, the better the


e efficiency. For example, a 150kW


maximumoutput and a 37.5kWminimum output results in amodulation ratio less than 4:1. In contrast, a boilerwith


(BMS). Compatibilitywith common data protocols used in building automation, such as BACNET, MODbus, LONbu KNX, aids integrationwith BMS, further optimising overall system efficiency. Froman installation perspective, it is important that any control panel or user interface is positioned so it is easy to access, read and opera Positioning this at eye level and/or at the top of the boiler not only allows this, it also protects the electronics b locating themaway fromthe heavy dutymechanical (andwater carrying) components inside the unit.


mation, us and


ate. ics by


The latest light commercial boilers offer a wealth of features and benefits, in terms of specification, installation and longevity alike. Integrated components and controls, aswell as advances in heat exchanger and pump design, have all contributed to improved


efits,


reliability and heat-up times.By utilising modern boilerswith these enhanced technological credentials, installers can be assured of powerful, efficient and long-lasting heating performance..


COMMERCIAL SUPPLEMENT


BOILER market


wwwheating


www.heatingandventilating.net


gandventilating net


September 2020


!"


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48