Should I Repair Or Replace My Air Conditioning System?

My air conditioning system is getting old, does it need replacing?

Like many good questions, the answer is not straightforward as it depends on several factors.

  • How many hours has the system run? Is it running 24/7 or just in the summer when it gets extremely hot?
  • Is it working extra hard cooling an area in which excess heat is being produced, such as a server room?
  • Is the system well maintained by a reputable company? Poor maintenance can add extra strain to a system leading to premature failure.

The average life of a well-maintained air conditioning system working in average conditions for 8 – 10 hours per day is approximately 15 years.


My air conditioning system has been very dependable for many years, so why has it needed some repairs recently?

Like any other excellent quality mechanical equipment, the first few years of use are dependable, especially with a good service and maintenance program, but after a while general wear and tear is inevitable. Most air conditioning manufacturers will supply a warranty on the parts for up to 7 years, but realistically not long after this time, you can expect to have to conduct maintenance repairs. Regular service of the system will allow engineers to find some of the potential problems and proactive repairs can be carried out before it becomes a larger issue.


What might fail in my air conditioning system?

Basically, air conditioning failures can be broken into three main areas,

  1. Mechanical failure – this typically will be a failure of the compressor or a fan motor.
  2. Electrical or electronic failure – this typically will be a failure of a PCB, an electrical contractor or one of the many sensors feeding information back to the PCBs. Unfortunately, quite often a mechanical failure will cause an electrical fault which also damages a PCB or another sensitive part.
  3. Refrigerant loss – a leak in the system causes all or some of the refrigerant to be lost and the system either becomes ineffective or fails completely.

Usually, with mechanical and electrical/electronic failures the faulty components can be replaced with manufacturer spares and the system brought back into working order. With the refrigerant loss, it can be more complex so we will explain this issue in more detail.

What can cause a refrigerant leak?

Refrigerant leaks can be caused by several factors, including

  • System vibration can cause a leak over time.
  • Time and age can cause joints, connections, and valves within the system to become eroded or to fail.
  • Corrosion and in particular the coils in the condenser (outdoor unit) and the evaporator (indoor unit). Both coils have air from the atmosphere blown over them and so if this air has a contaminant which corrodes copper, in time the coil will fail, and the refrigerant will leak out of the system. These contaminants can be quite simple Volatile Organic Compounds (VOCs) such as cleaning sprays, air fresheners and “off-gassing” by building materials and furniture. Keeping coils clean through regular servicing is important to extend their life.


Can I just get the system refilled or topped up with new refrigerant?

This question can be answered very simply – No. This would be a direct contravention of the 2014 EU F-Gas Regulations (517/2014). Under these regulations, the air conditioning operator (usually the owner) and the third-party contractor have a legal responsibility to prevent F-Gas released into the atmosphere. As soon as a leak, however small, is discovered there is a responsibility to stop the leak without “undue delay”.


Why is a refrigerant leak considered so serious?

All refrigerants have an environmental impact if released into the atmosphere. There are still some air conditioning systems in use which use Hydrochlorofluorocarbons (HCFCs) as refrigerants. These are a family of chemicals consisting of hydrogen, chlorine, fluorine, and carbon. HCFCs are ozone-depleting substances, and their use has been phased out in the UK. HCFCs have exceedingly high global warming potential. R22 is an example of an HCFC which may be found in an old air conditioning system. Newer air conditioning systems use Hydrofluorocarbons (HFCs) as refrigerants, but these still have an exceedingly high global warming potential. R410A and R407C are examples of HCFs found in air conditioning systems.


Can a refrigerant leak be repaired?

In most situations, a refrigerant leak can be repaired unless the system is very old, and the damaged part is no longer available as a spare part. In the case of a coil failure then it is usually best to replace the complete coil as local repairs can be effective, but then the coil can fail in a different place quite soon. Once a leak has been repaired then the system must undergo a pressure test to ensure there are no other leaks.


The leak in the system has been repaired can I now refill the system with new refrigerant?

If the system uses R22 refrigerant, unfortunately, the answer is no. R22 is an HCFC, and these are now banned refrigerants. If a system running on R22 loses or has the refrigerant removed to conduct a repair, then this is the end of life for the equipment as all that can be done with R22 refrigerant is for it to be recovered and sent for disposal.

If the system uses a refrigerant with a Global Warming Potential (GWP) of less than 2500 then, once the engineer has correctly prepared the system, it can be refilled with virgin or reclaimed refrigerant. Reclaimed refrigerant is previously used refrigerant which has been recovered from a system and reprocessed at a specialist plant to remove all contaminants to restore it to virgin quality.

I’ve got some refrigerant in an old redundant system can I transfer that to my repaired system?

Basically, the answer is no, unless the refrigerant is not a banned refrigerant, and it is recovered and then treated to become a reclaimed refrigerant.  For small quantities, this is not economically practical.


How do I decide whether to repair or replace my old air conditioning system?

Like most CAPEX projects it comes down to budgets and how business-critical a fully functioning air conditioning system is. In today’s business environment the care of staff is critical and so probably your air conditioning system is more important than you may have previously considered.

Salix Mechanical has over 30 years of experience in helping clients by conducting surveys of air conditioning equipment and providing balanced advice. If you have any questions or concerns about your equipment, contact Salix Mechanical today to arrange your free no-obligation site survey.

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Rob Tuffin