Your heating & hot water on a plate!
July 04th 2007

High efficiency—fully modulating boilers and plate heat exchangers have changed the face of commercial heating and hot water installations !

Aseries of exciting technological advances in recent years has changed the way that many enlightened consultants and installers look at the design of commercial heating and hot-water systems.

However, there still remains a perception , among some out there, that it is always better to separate heating and hot water in commercial premises – this is simply not the case.

The high water content and minimum turn down ratio with older style boilers and calorifiers was associated with poor energy efficiency due to boiler cycling and excessive stand by losses. Todays ultra modern boilers and plate heat exchangers have the advantage of low water content and are fully modulating which leads to the efficient production of both heating and hot water services.

The Stokvis Econoflame range of premix boilers for example ( 43 boilers - outputs ranging from 45kW to 1031kW, semi condensing and fully condensing models all with stainless steel heat exchangers), modulate on a frequency – inverter controlled fan and a pressure controlled gas valve, greatly boosting their efficiency compared to a typical boiler set up. (NB. All Econoflame premix boilers are ECA listed and all qualify for Enhanced Capital Allowance. Part L requirements are exceeded .Nox emissions are the lowest in Europe)

Many existing commercial installations comprise a large cast-iron sectional boiler feeding the demand of a calorifier and off peak loads tend to be small.This means that the boiler will be cycling on and off all the time,wasting valuable energy. In addition, the storage capacity of the calorifier – if excessive – leads to heat being leaked to the plant room, compounding energy wastage.

While it is true that a higher primary heating load is required for a system that incorporates a plate heat exchanger, this is easily overcome by ensuring that the hot water services take priority over the heating load. Since even on part load, the requirement for hot water services can be quite high, boilers can be sized to ensure that a normal off peak load falls within the modulation range of the boiler.

Another argument put forward by those advocating separate hot water and heating systems is that this system results in relatively low loads. In fact, although there are higher loads associated with the use of a plate heat exchanger, these are only applied for a relatively short period of time. Plate heat exchangers use the boiler capacity more effectively than an old fashioned boiler and calorifier set up – which requires a lower load but extending over o longer period. A system based on a plate heat exchanger combined with a low water content, fully modulating boiler is inherently more energy efficient .

Stokvis, in their endeavour to push the boundaries of energy efficiency even further using a boiler and plate heat exchanger combination, have introduced the ‘C’ series of plate heat exchangers. The ‘C’ stands for condensing, and their design enable the principle of condensing to be utilised both for the heating and hot water loads. If the return – water temperature to the boiler is above dew point of the flue gas, there is little point in specifying a condensing boiler, however, specifically designed to operate with lower flow and return temperatures – primary flow 70°C and return temperatures achieved of around 45°Cthe ‘C’ series when married to a fully condensing Econoflame boiler can significantly increase the seasonal operating efficiency of a system.The ‘C’Series is available in three ranges - a total of some 50 units with outputs up to 742kW In a nutshell there are many very good reasons for having your heating and hot water on a plate !!

Stokvis Energy Systems was established in 1985, since then we have grown in stature and product range and today provide ‘state of the art’ Boiler Plant, Plate Heat Exchangers, Pressure sets, Booster Sets and complete Packaged Plant Rooms, many of which are already installed in some of the UK’s most prestigious buildings. A national team of professional and committed sales engineers work in close liaison with clients, whether Consultants, Contractors or End Users, in selecting the most suitable equipment for their specific project requirements.

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