There are convincing financial reasons why companies should strive towards improved energy efficiency. John Durbin looks at how the economic argument impacts on air conditioning.

Draft European Energy using Product (EuP) legislation stipulates that air conditioning equipment will soon need to demonstrate 'seasonal efficiency' on energy labels. Although the industry could be forgiven for issuing a collective groan at the prospect of even more regulation, this policy could be good news for your customers - building managers looking to cut running costs and improve their companies' bottom line - and therefore good news for you.

Real performance of an air conditioning system, generally expressed in terms of nominal performance, is likely to vary from predicted performance. However, by assessing and then improving real-life performance, huge increases in efficiency are possible.

The new EuP legislation will require seasonal efficiency ratings for all air conditioning equipment, meaning that performance will be calculated and expressed according to its seasonal efficiency rating over the year. This will eventually appear on a new energy label, giving users a better idea of anticipated real life performance.

Because the Seasonal Energy Efficiency Ratio (SEER) is a more accurate measure of a system's efficiency than the more traditional EER, huge increases in efficiency can be demonstrated.

Manufacturers are anticipating this legislation and, indeed, products are already on the market containing seasonal inverter technology. This delivers higher annual seasonal efficiencies than the latest super inverters and offers big improvements over contemporary non-inverter systems.
This new technology takes account of multiple cooling and heating temperatures as well as the unit operation at partial load as well as full capacity. It will also consider the power consumed by equipment in auxiliary mode when the compressor is off.

Seasonal efficiency ratings are not the only development that can help boost energy efficiency. It can also be improved by monitoring efficiency remotely or by using 'intelligent systems'.

Taking remote monitoring first, the operating efficiency of an ac system not only has an impact on emissions and energy consumption, but it also affects the reliability, cost of maintenance and life expectancy of the system. Keeping air conditioning systems running at an optimum level results in a longer lasting, cheaper to run system that produces fewer emissions.

The best remote monitoring will offer additional energy saving functions, designed to remotely adjust the operating parameters of air conditioners to ensure optimum energy efficiency. Energy saving can be obtained by using remote weather forecast information local to the specific site. This information is combined with data collected from the air conditioners.

Judgments can then be made based on this information and, if energy saving measures are possible, they can be made remotely. Systems such as these will also account for occupancy levels and variations in installation (piping lengths etc.) when calculating energy saving potential.

However, even bigger energy efficiencies can be made using heat recovery in balanced mode within a variable refrigerant volume (or flow) system. This intelligent approach to heat recovery can deliver coefficients of performance of 9 or even 10. Yet, it is still not widely recognised in the UK market that a heat recovery system operating in a balanced mode can increase energy efficiency levels massively.

Achieving balanced mode operation might involve 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 require heating or hot water. To do so, the indoor units need to be arranged to maximise 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.

• The author is Daikin UK's engineering department manager