ACR Journal

April | May 2023 Energy costs are on everybody’s minds right now so in addition to choosing an energy e cient low GWP refrigerant, it’s a good time to be reminded of the other actions that can be taken to minimise wasted energy use. The service and maintenance of a cooling system can help to improve energy e ciency and reduce total emissions. Such actions will likely pay for themselves over the lifetime of the equipment. Optimal energy efficiency To ensure systems continue to operate at their optimum level, a good maintenance programme is recommended. In recent years there has been a decline in end users seeing the value of routine maintenance in favour of a more reactive type of approach. For these users, this could prove to be more costly in the long run than paying for good regular maintenance. This is probably the easiest strategy to employ but often end users do not see the benefits of spending money on a system that appears to have nothing wrong with it. However simply cleaning the heat exchangers, ensuring fans are REFRIGERANTS 30 Better energy efficiency can be achieved through good servicing and maintenance, says Dave Richards, UK Head of Sales at Climalife. Making maintenance a priority operating correctly and checking the system operating parameters can have a significant impact on system emissions. Figure 1 shows the impact of increasing condensing temperatures with R-449A at low and medium temperature conditions. Even a very small increase in the condensing temperature can lead to significant decreases in energy e ciency, for example, an increase from 25°C to 27°C condensing temperature can lead to a 5-8% loss of compressor energy e ciency. It doesn’t take much dirt or debris on the condenser coil to cause a small pressure increase and it is easily prevented by regular use of cleaning products which will prevent build-up of debris that can block the air flow through the coils, maintaining the optimum energy e ciency. In situations where condenser fans have either failed or are malfunctioning, energy e ciencies could easily drop by 25% or more. Oil checks Regular oil checks should also form part of a good maintenance regime, to ensure all the moving parts of a compressor are lubricated to their optimum level to give you optimum energy e ciency. Combined with regular cleaning of heat exchangers, this will have a large positive impact on energy e ciency. A test kit, such as Acitest Unipro WW from Climalife, can instantly check the acidity level of refrigerating oils. This can help to increase safety and productivity of installations. Coil cleaning Coils should be cleaned within ventilation systems as the coil is in the direct air flow path on all ventilation systems. Therefore, it has a direct impact on the rate of air flow, e ciency of heat transfer and indoor air quality. When coils are covered in dirt or debris it adds an extra layer between the air that is blowing over the coils and the refrigerant inside that absorbs and releases the heat. This layer of dirt acts like an insulator and makes heat transfer less e ective. Having units with dirty coils not only leads to higher energy bills, poorer air quality and system reliability can also be adversely a ected. Even relatively low levels of deposition on the coils can cause these detrimental e ects and potentially decrease system lifetime. A powerful cleaning product such as Frionett Coil Cleaner, from Climalife could be used for the degreasing of indoor unit coils. By using a product such as this, you will see the cleaning and degreasing power unblock the airflow by eliminating Volume 9 No.3 Figure 1: Degradation of C.O.P. with increasing condensing temperature for R-449A here Dave Richards