Poor water quality impacts on heat transfer efficiency in two ways: Impairment or blockage by debris, or through the development of a restrictive or insulating deposit layer. Suspended solids may remain from construction phase, or are generated by corrosion, precipitation of minerals, biological growth or fill water contamination. Protecting heat transfer is essential to overall system performance and plate heat exchangers (PHEx) and terminal emitters, such as fan coil units (FCUs), are often numerous and particularly susceptible.  Blockage of strainers protecting these components is one of the most common problems operators experience e.g. A large commercial inner city development could have > 1,000 FCU’s and a large district heating scheme > 2,000 individual Heat Interface Units (HIU’s – small PHEx per residence).

Reactive maintenance due to mechanical defects on pumps, valves, seals, strainers is costly, disruptive, labour intensive, and invariably leads to customer complaints and costly disputes. Reduced component lifespan raises building life cycle costs which is a major concern for building owners, landlords and operators.

Detrimental deposit layers created by corrosion, scale or biofilms reduce flow, impair heat transfer, seize moving parts and generate suspended solids. To ensure the ‘energy carrier’ remains in its optimal state a robust all encompassing water treatment strategy must be implemented, it should include side stream filtration for effective ‘polishing’ and reliable water chemistry, both of which are complimentary to a microbiological monitoring and biocidal dosing regime.

The EnwaMatic® is a multifunctional technology that provides:

• Filtration size: Side stream, media ‘depth’ < 5 microns.  All particle types, irrespective of   density or magnetite content.  ‘Surface filters’ – cartridge / bag are more  prone to blockage.        
• Corrosion inhibition: Alternative to chemical dosing.  Maintains total iron levels < 1.0 mg/l. (BSRIA  < 6 mg/l).        
• Scale control: Removes excess hardness by pH elevation, ‘controlled precipitation’.       
• pH control: 8.7 – 10.7  (Not suitable for aluminium components - contact ENWA for  alternatives.      
• Air separation: Side stream removal of excess air / micro-bubbles.