Out with the new, in with the old

It can often be more cost- and energy-effective to refurbish existing building services plant than replace it.

With energy costs in the UK continually increasing, most (if not all) organisations are looking for ways to reduce their energy consumption (and therefore their carbon emissions). Refurbishing existing building services plant – such as air handling units, fan coils, boilers and chillers - can be more cost effective than replacing with new.

Not only does this refurbishment approach reduce the overall raw material consumption and its embedded carbon footprint, it can also effectively upgrade existing plant to the latest standards - enabling reductions in running costs of up to 50% (dependent on design and current condition).

Just as importantly, a refurbishment approach can reduce capital costs. For instance, in the case of air handling units (AHUs), depending on the extent of works required, we have found that refurbishment can cost between 20% and 50% less than the replacement option.

To put that into real financial terms, consider an AHU with an airflow of 7m³/s that incorporates all of the heating, cooling and ventilation functionality one would expect. To supply and deliver this new would cost approximately £12,500 (based on good access and the above specification). To refurbish a similar unit by: replacing all the internal components, treating any corrosion, replacing damaged external panels, re-commissioning and providing a 12 month warranty would cost approx £9,500 – a cost saving of 24%.

 However experience shows that when you include additional costs such as removal of the existing AHU and adjacent ductwork, fitting of new ductwork and refitting/adapting all the connections, the savings, compared to buying new, can increase to 50%.

Also, when longer lead-in times and the potential disruption of delivery and onsite fitting are taken into account, AHU refurbishment starts to look even more appealing.

Understanding the processes involved

In all such cases, the first stage is an initial inspection to assess the current condition, the potential for refurbishment and the cost implications of the options available. Remaining with the AHU example, clearly all components will suffer some age deterioration, but this will have affected some more than others.

Cooling coils, for example, may have suffered a corrosive oxidation effect, especially in areas of high air pollution. There will also be considerable wear and tear on moving parts in fans and motors, while static components may have years of life left in them.

In addition, refurbishment options should include mechanisms for reducing energy consumption, perhaps by using newer, more efficient designs of component that comply with modern standards and specifications. The efficiency of fans, fan motors, heating and cooling coils, insulation and direct expansion equipment can all be improved in this way. With larger items of equipment there are also access considerations, which may make it very disruptive to install new plant.

Once the evaluation has been completed, a method statement and risk assessment can be produced, along with detailed costings to facilitate the decision making process.

Clearly, these same principles can also be applied to other building services plant, including fan coils, air curtains, chillers and boilers. The key is the application of specialist expertise to assess the situation and arrive at the best solution for those responsible for the effective running of the plant.

For more information please contact Envirotec

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