Economic uncertainty is increasing the heat on FMs. Managers across the country are now seeking double-figure efficiencies on their air conditioning systems. John Durbin offers 10 tips on how to keep your cool while also reducing carbon emissions
30 September 2010
1. Switch to
VRV systems
Variable Refrigerant Volume (VRV) technology delivers typical efficiencies of between 300 per cent and 500 per cent – among the highest levels being achieved in the industry.
2. If possible, employ heat recovery
Within the VRV system, employing heat recovery has been proven to deliver a Coefficient of Performance (COP) of more than ten – previously unheard of. Balanced mode operation is achieved by cooling one area of
the building, which is experiencing the highest heat gains, and transferring that reclaimed heat to other areas of the building that need heating. (The same process can also be used to provide hot water for kitchens and washrooms.)
3.Understand the system The system works by indoor units maximising the occasions when this balanced operation can take place, with the heat recovery system diverting recovered heat to wherever it is needed, thus contributing significantly to the goal of
zero heat rejection.
4. Analyse right from the start
Consider a building’s multiple requirements, usage patterns and varying occupancy levels in order to design a fully integrated system that optimises energy efficiency and heat recovery. Doing so will help you to achieve those industry-beating efficiency levels. A building manager will not necessarily be able to input into the early stages of design. However, they are more likely to be able to exert their influence in the efficient maintenance of these systems.
5.Consider operating efficiency
An air conditioning system’s operating efficiency has an impact on emissions and energy consumption; it also affects the reliability, cost of maintenance and the life expectancy of the system. If air conditioning systems can be kept running at an optimum level, the result is longer lasting, cheaper to run units that produce fewer emissions.
6. Remote monitoring
Remote monitoring involves gathering and analysing data from a particular system, usually by the air conditioning provider via specialist equipment, which uses an internet connection, It is a useful weapon in the fight to ensure that systems operate at their optimum level.
7. Fault prediction If using a remote monitoring system, ensure that it also provides a malfunction prediction module too. Via constant monitoring and analysis of data from the equipment, any abnormalities can be picked up at an early stage. This means failures can be prevented and possible down time reduced to an absolute minimum. Ideally, this service will also flag certain operational issues such as blocked or contaminated air filters or heat exchangers. As a result, performance and efficiency can be improved. This optimisation will also increase the lifespan of the equipment.
8. Energy saving
The best remote monitoring equipment will also offer an energy saving function. Such systems should be designed to remotely adjust the operating parameters of air conditioners to ensure optimum energy efficiency. They can include a remote weather forecast provision which is then combined with data collected from the air conditioners. If energy saving measures are possible,
they can be made remotely.
9. Look for efficiencies By examining how the real-life performance of an air conditioning system varies from its predicted performance, a canny FM can root out further efficiencies.As predicted performance is generally expressed in terms of nominal performance, there can be significant differences between this and actual performance.
10. Get back
to basics Finally, don’t forget the basics – maintenance and inspection. Regular maintenance and servicing visits are vital to ensuring optimum performance, as is making sure units are clean and dust-free. Something as simple as a self cleaning cassette can optimise performance. It will maintain peak operational efficiency and significantly reduce the lifetime cost of the air conditioning system. Post-inspection and compliance reports can also contain valuable efficiency information.
Top tips
- Heat recovery – taking excess heat energy (from refrigeration units or IT suites) and reusing it elsewhere
- Heat recovery in balanced mode – as above, but with the arrangement of the indoor air conditioning units to optimise performance
- Utilise remote monitoring – to prevent problems from occurring and to optimise performance
- Ensure regular servicing and cleaning of equipment – something as simple as self-cleaning filters within indoor units can increase efficiencies
- Take advantage of air conditioning inspections – not only are they compulsory (above a total of 12kW of cooling installed) but the subsequent report will offer useful information to improve efficiencies
John Durbin is engineering department manager at Dalkin UK
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