How to Reduce air Conditioning Cost & Malfuctions

Almost every home in Hong Kong relies on air conditioners to keep them cool during warmer weathers. During hotter seasons, air conditioner costs can constitute over 50% of a household's electricity bill and because of the high usages, it is also one of the appliances that are more prone to malfunctions, which includes, complete breakdown, warm air outflow, dripping, circuit board errors, leakage of refrigerant etc.

Air conditioner malfunctions usually happens when its proper functioning is most needed, and the ability to find the right engineer to fix it quickly and cheaply will be challenging. In addition to offering our services in a responsive and reliable manner, below are some tips from V Repair to help you reduce the cost of air conditioner and the probability of malfunctioning.

Get an energy efficient air conditioner

  • Most of the air conditioner manufacturer will affix an energy label to the product (in accordance to the EELS). The label will have a grading from 1 to 5 and 1 being the most energy efficient

  • Energy Efficiency Ratio (ERR) - it's the ratio between the product's cooling capacity (BTU/hr) to its power consumption (W), as such the higher the EER, the better your air conditioner is. Typically this number ranges from 8 - 10

  • Coefficient of Performance (COP) - similar to EER, its also a metric for efficiency with the product's cooling capacity over its power consumption. The only difference is that the unit of the cooling capacity is in watts. Again, the higher the number, the better it is. Typically, it ranges from 2.3 to 2.9

Sizing the air conditioner correctly

  • Sizing is important in a way that if the air conditioner is oversized, there will be energy wasted and the product will be more prone to malfunctions and large temperature fluctuations indoor due to the frequent on/off of compressor. An undersized air conditioner simply can't get the job done.

  • Accordingly to the Electrical and Mechanical Services Department (EMSD), assuming the ceiling height of 2.7 sq m, the below guidelines serves as an indication

For cooling capacity, 1 KW - 3,412.14 BTU/hr

For cooling capacity, 1 KW - 3,412.14 BTU/hr

Air Conditioner Maintenance

The efficiency and the performance quality will definitely deteriorate over time, the more you use it the faster the deterioration and depending on the make, it could be within 2-3 years. Regular cleansing and maintenance can slow down the deterioration and prevent premature malfunctions. Here is a couple of common issues with air conditioners in Hong Kong, some you can deal with it yourself, others would need to be done by experienced maintenance professionals.


Most residential flats use split type air conditioners, which would have similar filter to the above. Source: Internet

Most residential flats use split type air conditioners, which would have similar filter to the above. Source: Internet

Clogged air filter will reduce air flow through the evaporator and increase energy consumption, it could also cause the air flow to be warmer and could potentially lead to clogging in the drainage pipes leading to drippings later on.

As such, air filters should be cleaned regularly (which is relatively easy) to avoid too much dust accumulation. You should follow the operation manual and literally just use wet towel and a brush to clean the filter, then put it back on.

When putting it back on, please ensure that the filter is secured and covers the whole area of the evaporator coil such that there is no gap allowing airflow to circumvent the filter and enter the evaporator directly.


While the air filter is the first line of defence in terms of stopping dust and dirt particles, but there is still a chance that some may slip into the blades, condensers, evaporator coils etc, as such a deeper/more thorough cleansing of the air conditioner is recommended on an annual basis to ensure your air conditioner functions normally and doesn't waste energy.


The evaporator / condenser is assembled with light grade aluminium thin sheets, which under normal circumstances should be tightly assembled by separated from each other. These fins are relatively easy to be bent blocking airflow or in some cases corroded. This can be detected visually, if that's the case, please get in touch with a professional to have that fixed if not replaced.


Depending on various factors such as frequency of usage, brand etc, leakage of refrigerant is not uncommon. With sufficient refrigerant, your air conditioner's cooling capacity will be lower, hence less energy efficient. Topping up refrigerant can solve the problem on a short term basis, but more importantly, one should find out the reasons, and if the leakage is severe, then replacement of the air conditioning unit should be considered. 

For split-type air conditioner, topping up of refrigerant is done on the outer unit, as such professional personnel should be contacted.

V Repair's scope of coverage helps to deal with more frequent issues, like topping up refrigerant, fixing the circuit boards (which relates to remote malfunctions), drippings and cleaning air filters. While we don't cover for thorough cleaning of the air conditioner unit, we will be more than happy to provide quotes for our responsive and reliable services.