Refurbishing plant in-situ

Published:  01 July, 2004

To bring old air-conditioning equipment up to modern standards of efficiency and performance, Airedale Service can refurbish existing plant in situ when it is not practical to strip it out and replace it.

With so much air-conditioning plant almost part of the fabric of the building, refurbishment can present major difficulties — a situation that has been addressed by Airedale Service.

Eventually, most air-conditioning systems, including chillers, close control and comfort units, will reach the end of their useful life. There can be many reasons for replacing existing systems, including mechanical failure, tighter energy-efficiency targets, noise-reduction strategies, refrigerant issues or capacity and performance problems.

Systems installed when a building is constructed are often very intimately connected to the fabric and structure of the building, and their removal can pose considerable problems. Larger plant is routinely positioned within the structure of a building before the project is complete, and any attempt to remove the redundant equipment can result in the need for structural alterations involving the expensive removal or modification to roofs, walls and access points.

In some cases the building may well have been extended or modified in some way, and, of course, there is the likelihood that the actual functional requirements of the structure have changed due to new tenancies, altered working patterns and general economic and technological progress.

To address these issues and provide building operators and users with an up to date, energy efficient system requires an on-site unit refurbishment programme to restore systems to ‘as-new’ condition and overcome many of the problems outlined above. Such an approach has been developed by Airedale Service with its ‘AsNew’ concept.

In situations where access is severely restricted, or where business-critical operations need to be maintained throughout the replacement programme, units can be rebuilt on site, replacing major components with new alternatives which take advantage of the very latest energy-efficiency technologies.

All-round benefits

Modern screw, scroll and reciprocating compressors are much more energy efficient than was the case a decade or more ago when many buildings were constructed with air-conditioning systems in place. In addition to more effective compressor design, additional investment in sophisticated controls, electronic expansion valves and much-improved fan technology have resulted in systems which produce much lower carbon emissions.

Compressors are now much quieter and have far less impact on the crowded urban environments which exist today. Improved control technology has also paved the way for the much wider use of free-cooling chillers in applications which involve continuous processes such as Internet, telecommunications and control of infrastructure.

Close-control units are now routinely provided with free-cooling cycles, and modern comfort units also benefit from this technology to provide energy-efficient cooling whilst simultaneously maintaining good indoor air quality.

Planned programmes

Airedale Service, for example, has developed an ‘AsNew’ service and can replace compressors, evaporators, fans and other major components with the very best that the market can offer, replacing aging and inefficient parts with the most up-to-date technology. Improved controls packages, which result in improved energy efficiency and reduced running costs, can also be included — and are always recommended as part of a refurbishment programme.

Together with the client, Airedale engineers agree a comprehensive schedule of works, which is designed to minimise disruption and downtime. In situations where large numbers of units are being refurbished, the programme will be phased so that there is always sufficient capacity to enable the building to operate as closely as possible to normal.

A dedicated team of engineers orders, checks and tests the new replacement parts and builds any sub-assemblies prior to installation. The same team then undertakes the refurbishment programme, according to the agreed schedule, and commissions the new system before handover to the client.

Minimal disruption

Airedale engineers involved in the AsNew programme work closely with the building owners and operators to ensure a successful outcome. By carefully considering all possible obstacles, expensive structural modifications to the building are unnecessary — avoiding a great deal of disruption, both to processes and staff, whilst sophisticated operations are maintained, especially important in areas of IT, telecommunications and finance.

AsNew is proving very popular in the financial-services industry. Service manager Adrian Trevelyan says, ‘Many of our clients operate sophisticated banking support services where continuity and reliability are essential.’

Environmental benefits

AsNew also addresses many issues that may have developed since the original system was installed. The replacement of systems employing ozone-depleting refrigerants is an obvious example which benefits the environment, as does the introduction of newer gases which offer improved energy efficiency.

Replacing traditional chiller components with up-to-date alternatives can have substantial economic and environmental implications. The New Part L of the Building Regulations inspires building operators to pay meticulous attention to both full-load and integrated par- load operating efficiencies. Updating chiller components can result in impressive full load energy-efficiency ratios (EERs) which are further enhanced when demand is reduced, enabling the unit to operate at part loads with minimum unit power consumption, resulting in reduced running costs and carbon emissions.

As-new is proving very popular in a wide variety of critical industries where downtime is not acceptable. Careful scheduling ensures minimum disruption and also minimises associated construction costs. Building owners are increasingly aware of the major benefits of this approach.

Airedale Service,Leeds Road, Rawdon, Leeds LS19 6JY.

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