27 February 2007

HOT WATER SYSTEMS THAT DEFEAT LEGIONELLA

Minimising the risk of Legionnaire's Disease is an important consideration in the specification of hot water systems for commercial, industrial and public buildings.  A memorandum from the Chartered Institute of Building Service Engineers details the strict safety codes which need to be followed.  These recommendations cover all aspects of sanitary hot water systems - from planning to installation, commissioning to maintenance.

Stokvis Energy Systems has researched the Legionella problem thoroughly.  However, while recognising the need to introduce a system which avoids static hot water, an area in which Legionella thrives, the company has also concentrated upon system efficiency.

An economical solution is essential if the problem is to be solved.  A hot water system must therefore be practical, cost-effective and meet public welfare requirements.

There is increasing pressure to move away from traditional large quantities of stored water to rapid, readily available hot water systems.  Another factor is the increased demand for smaller, space-saving units.

A packaged plate heat exchanger provides instant hot water at extremely efficient rates - a method of heating that has been popular in Europe for many years.  In essence, plate heat exchangers take the cold water supply and heat it directly on demand, rather than heating and storing the water.

The unit comprises a series of vertically mounted, corrugated plates in a sandwich structure and works on a primary and secondary contra-flow system.  The corrugations create a greater surface area and turbulence between the plates ensuring that a high degree of heat transfer is achieved.

The corrugated stainless steel plates are simply clamped together with factory fitted primary and secondary flow and return water connection placed at one end for ease of installation.  Should cleaning be necessary, the plates are easily unclamped giving direct access to both sides of each plate.

The packaged units incorporate pumps, motorised primary control valve, temperature, time, control and safety controls and flow, return and cold feed, connections to give alternative modes of operations including normal/reduced flow temperature and normal temperature/off, as required. 

On their own, plate heat exchangers help to alleviate the concern about Legionnaire’s Disease and when packaged together with peripheral components they offer a compact, space saving alternative to the traditional approach.

When used in conjunction with high efficiency, fully modulating, condensing or semi condensing, gas fired boilers such as the Stokvis Econoflame range of boilers, a very powerful, versatile package evolves.

A recent innovation from Stokvis is the ‘C’ Series of Econoplate Plate Heat  Exchangers. The ‘C’ series has been specifically designed to operate at lower flow and return temperatures and to marry with fully condensing boiler operation – giving optimum efficiency and optimum performance – vital points to bear in mind in view of the new EPB Directive and Part L requirements.