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Compressor Maintenance Guide

Maintenance is a critical activity in the HVAC sector, not least because a malfunctioning compressor costs time, money, and business. It can also have an undesirable impact on the health and comfort of building occupants if it results in the poor performance – or failure to perform at all – of the HVAC equipment serving a living or working space.

The trouble is that the perception of maintenance is often negative because the word ‘maintenance’ itself implies keeping things as they are… retaining the status quo… preserving the current state of affairs… continuing along similar lines… more of the same. The inference is that maintenance is a fixed pursuit that offers no room for improvement and contributes nothing to quality of life.

This is wrong on two levels. First, it’s always possible to boost the performance of a maintenance regime. Indeed, it should be seen as a crucial element in every business’s continuous improvement cycle. Secondly, rationalising the compressor maintenance operation can lead to big improvements in the HVAC operating process.

The cost of a sound maintenance programme is ludicrously low when compared with the cost of dealing with, say, a catastrophic compressor failure or refrigerant leak. As well as preventing such disasters, effective maintenance can also make a significant contribution to the bottom line by ensuring that the compressors are energy efficient and therefore produce lower power bills and higher environmental performance.

But the most compelling argument in favour of a properly implemented maintenance strategy is that it guarantees reliability. And reliability is magic: just about every indicator – from safety to environmental performance, morale, retention, and customer service – improves if you establish reliability as a core value.

What is compressor maintenance?

Compressors play a critical role in the overall efficiency of HVAC systems. They are at the heart of the HVAC system because they circulate refrigerant and therefore transfer heat from the refrigerant to condenser.

As the name suggests, the primary function of the compressor is to squeeze refrigerant gas. This raises its temperature and pressure, and the resulting high-pressure gas then flows to the condenser where it releases heat and converts into a liquid.

The liquid refrigerant then moves to the evaporator coil where it absorbs heat from indoor air, turning back into a low-pressure gas and completing the cycle.

A smoothly functioning compressor improves the system’s energy efficiency, which saves money on energy bills and helps protect the planet from climate change.

However, to achieve this, the compressor must operate at its optimum level, and that requires effective maintenance.

Maintenance means different things to different people and in different contexts but when it comes to HVAC compressors, it really comes down to servicing the equipment such that it ensures longevity, efficiency, and optimal performance.

Regular inspections or tune-ups can, for example, help prevent refrigerant leaks, overheating, and electrical problems as well as making breakdowns less likely.

Maintenance can include regular routine inspection of the compressor, cleaning condenser coils, lubrication, checking refrigerant levels, insulating refrigerant lines, monitoring airflows, and calibrating controls.

The actual regime, however, will depend on your particular circumstances including how many compressors are involved, what types they are, their applications, and how hard they are being asked to work.

Why is compressor maintenance important?

As well as maximising energy efficiency, good maintenance also helps prevent the disruption that can be caused by unexpected malfunctions. Furthermore, it can extend the lifetime of the equipment and provide peace of mind that everything possible is being done to keep the HVAC process running well and downtime is being kept to a minimum.

The cost of doing maintenance can be off-putting, but ignoring this crucial activity is a false economy because the cost of not doing maintenance will almost certainly be higher. Indeed, its outlay is absurdly low compared with the price – both financial and in terms of stress – of dealing with a compressor failure.

An effective maintenance programme offers a host of benefits. For example, it results in fewer breakdowns and reactive repairs, longer equipment life, lower energy consumption, and better regulatory compliance.

But the advantages don’t end there. Maintenance is the most cost-effective way to ensure reliability, safety, and energy efficiency of compressor equipment. It is also an area ripe with opportunities. According to some studies, total costs could be slashed by up to 50% simply by switching from reactive to predictive maintenance.

But the most compelling argument for properly implemented maintenance is that it guarantees reliability and therefore peace of mind. Reliability – the ability of equipment to achieve its intended function consistently and dependably without failure or breakdown – is the keystone when it comes to being able to trust the performance of compressors.

Neglecting maintenance will inevitably result in a steady decline in air conditioning performance while energy use and fuel bills steadily increase. That makes a compelling case for effective investment in maintenance in partnership with a tried and trusted expert in the field.

Compressor Servicing

What are the types of compressor maintenance?

There are, essentially, four maintenance categories. The first is reactive – in other words, it requires a response to a problem – and the other three are planned and preventive – they anticipate problems and aim to neutralise them before they happen.

Corrective maintenance is essentially a ‘run-to-failure’ approach that involves restoring defective equipment to a working condition as quickly as possible after it has stopped working. Since it means fixing breakdowns is classed as a ‘run to failure’ approach. It is reactive and unplanned because remedial work is carried out as and when equipment fails in operation. It will not deliver high performing HVAC equipment and is also expensive in the long term, leading to the depreciation of asset value.

Planned preventive maintenance (PPM) is designed to ensure the best possible operation of equipment and avoid expensive unforeseen equipment failure or shutdowns. Unlike corrective maintenance, PPM is designed to find potential problems before they lead to equipment failure.

  • Corrective – tasks executed to repair a faulty device after it has broken down.
  • Predetermined – tasks completed according to a calendar schedule or operating time.
  • Predictive – tasks conducted by monitoring the performance of equipment using formulas to project future breakdowns.
  • Condition-based – tasks performed by monitoring the condition of equipment using real-time sensor measurements to help avert unexpected future failures.

Compressor maintenance can broadly be split into two sections – that performed by the customer and that performed by a compressor overhauler like LH-plc.

There are essentially eight actions in the first category:

  • Check the compressor for leaks both visually and using leak spray (a clue that there might be a leak somewhere in the system is low refrigerating pressure).
  • Check that suction and discharge pressures are within the standard operating range of the compressor.
  • Check that the motor’s Amps are within standard operating range.
  • Inspect contacts and tighten terminals as necessary.
  • Megger-test the compressor to check the compressor’s resistance.
  • Perform an oil test on the compressor to check for leaks.
  • Replace the oil in the compressor.
  • Record operating pressures, amperages, and voltages and make sure they are within the manufacturer’s recommending operating parameters.

Maintenance that should be conducted by compressor overhauler includes:

  • Replacing suction and discharge valves and valve springs.
  • Swapping out mechanical parts that have worn.
  • Replacing worn bearings or if the bearings have exceeded the manufacturers recommend run hours.
  • Replacing piston rings and discharge valves.
  • Checking the tolerance on the crankshaft journal and connecting rods and replacing them if they are out of accepting operating range.
  • Performing a full pressure leak test.

What can LH do for you?

LH-plc provides a comprehensive range of services that support compressor and chiller maintenance, including fault finding, commissioning and decommissioning, refurbishment and repair, and specialist maintenance.

  • Compressor servicing and maintenance: Enhance the performance and dependability of your industrial compressor systems with LH-plc’s comprehensive Compressor Servicing solutions. 
  • Specialising in compressor servicing and maintenance, including air compressors, rotary screw, scroll and reciprocating compressors, our approach is grounded in a deep understanding of your unique business needs, ensuring that your systems function seamlessly.
  • Turbocor compressor maintenance: The unique characteristics of Turbocor compressors make correct maintenance essential. The principles behind the Turbocor compressor are completely different from conventional compressor systems. LH’s engineers have over 15 years’ experience working with Turbocor chillers.
  • Chiller fault finding: We employ cutting-edge technology to diagnose faults, including sophisticated infrared thermal imaging cameras which help identify and quantify heat sources.
  • Chiller commissioning and decommissioning: Following the introduction of the F-Gas Regulations and other related legislation, refrigerants must be handled and disposed of carefully as part of a formal decommissioning process of air conditioning and chiller systems.
  • Chiller refurbishment and repair: Replacing chillers involves expense and disruption as well as being subject to relatively long lead times whereas refurbishment is cheaper and more flexible.

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BOX 1

Develop a maintenance strategy

Maintenance is vital to the smooth running of any business that operates machinery, including compressors. Good preventative maintenance cuts running costs and reduces the likelihood of potentially expensive breakdowns. It can also extend the lifetime of equipment and provide peace of mind that you are doing everything you can to keep the HVAC equipment running and downtime at a minimum.

A HVAC maintenance strategy provides a complete outline for how to minimise downtime, keep maintenance costs under control, and ensure compressors are working at or near capacity. The best strategies help to maximise compressor performance and save money. To succeed, they must include three critical elements – effective planning, documentation, inventory management, and education and training.

  • Planning: Maintenance planning starts with one simple rule: keep the equipment operating. Planned preventive maintenance (PPM) – see ‘What are the types of compressor maintenance?’ in the main body of this guide. Well-designed PPM can detect failures before they happen and avoid disruption to the compressor’s smooth functioning.
  • Documentation: Record keeping is essential if you are to maintain control over the maintenance process. That’s why an effective maintenance strategy includes documenting maintenance activities such as dates, times, the nature of the work, and who carried it out. As well as helping you to track your system’s maintenance history, accurate and up to date written records (even if they comprise no more a simple logbook) also aid you in ensuring that warranty requirements are met and enable you to troubleshoot should a problem arise.
  • Inventory management: Catalogue spare parts and components of the HVAC system, including details such as dates purchased, serial numbers, and particulars relating to warranties. This will alert you to when it’s time to replace parts and help you lessen the impact of unexpected ‘fix it’ costs.
  • Education and training: The HVAC sector is particularly innovative, and its technology is ever-changing and improving. It is essential that you remain informed and stay up to date with current developments and working practices. That is why education and training play such an important part in any effective maintenance strategy.

Help with all of these elements and more is available from companies like LH-plc, which can provide support and resources to achieve the best possible compressor maintenance results.

BOX 2

Maintenance contracts explained

A maintenance contract is an agreement between the customer and service provider which outlines the tasks, schedules, and service frequency intervals. This differs from a repair contracts, where maintenance providers offer what seems like a good deal where they will complete repairs under a certain value (say £1,000) within the monthly retainer.

Maintenance contracts can offer solid business benefits including financial savings, quality assurance, and peace of mind. Essentially, there are four maintenance contract options – an in-house service and maintenance team, OEM (original equipment manufacturer) specialists, a third-party maintenance provider, or a combination of these.

The outlay for employing an in-house maintenance team can be high when considering staffing and training costs and the expense involved in managing inventory.

Engaging an OEM specialist does not necessarily allow you the best opportunity to capitalise quickly on the latest innovative products.

Typically, the third option – a contracting a third-party to perform maintenance tasks as and when necessary – offers the best value for money because expert technicians can offer the best in terms of preventive maintenance and, should there be any equipment problems, they can ensure they are fixed efficiently the first time every time.

Contact LH-plc to discover how we can help you with your compressor maintenance needs.