Maintenance prevents, detects and corrects the failures of an air conditioning system. Hence the importance of not skimping on investments that support the proper functioning of this type of equipment.
by Duván Chaverra Agudelo
Experts say that the first thing to keep in mind when talking about maintenance in air conditioning systems is that this should not be billed as an expense, but as an investment that will protect the equipment and extend its life.
The detection, prevention and correction of faults are ensured by proper maintenance. Bacteria are the main enemies of different air conditioning systems, either split, window type or compact, central by means of ducts or a fan coil. For that reason, special care should be taken of filters and other places where humidity and temperature are favorable for these biological contaminants.
To deepen the subject, this time we invited three experts in the field of maintenance of these systems. They are Fernando Cabrera, air conditioning and energy efficiency consultant; Alfredo Sotolongo, president of Protec Inc, and Camilo Botero, president of Camilo Botero Ingenieros Consultores.
For Sotolongo, any maintenance plan, whether air conditioning or any other type of electromechanical system, must be based on manufacturers' recommendations and common sense. "You have to start with the simplest: changing the filters of the units, which prevents the coil from getting dirty and the unit losing efficiency, this is in addition to the manufacturer's recommendations," said Sotolongo.
Generally, experts recommend that the washing of evaporator and condenser coils be done with a damp cloth rubbing every corner to remove excessive dust and dirt.
Fernando Cabrera highlights the issue of times as another important factor to take into account: "The regularity of the service is agreed with the client based on the use of the conditioned space, for example the houses can have a bimonthly regularity, the monthly offices and special rooms of clinics every week. Parallel to this, the type of equipment that the installation has is studied to evaluate how much is the estimated time per team to carry out maintenance and based on this the most appropriate technical personnel are coordinated".
For his part, Camilo Botero comments that "the maintenance of these systems is no different from any industrial preventive plan. Activities must be perfectly defined, for example in Carvajal S.A., when I was engineering manager, we called it "Lemop" (Lubrication, Electronic, Mechanical, Operational, Predictive). A manual must be made with all the activities perfectly defined in time, frequency, level of the personnel that executes them, tools, security, among others".
Engineer Botero agrees that the manufacturer's recommendations should be well applied to avoid damage to the devices, but also explains that the issue of the environmental conditions where the device operates must be taken into account: "The operating regime of the equipment (one, two, three shifts or critical equipment that cannot be turned off throughout the year) will be taken into account. The environment where they are located is very significant, for example if there is too much dust, it is brackish, or it is left out in the open."
Maintenance according to...
Regarding the issue of maintenance according to its components, the president of Protect said that in small units that are used in residential and some commercial applications, the compressor is the most important element. "You have to make sure that the condenser is free of airflow obstruction and stays clean. In addition, operating pressures must often be checked to ensure that there are no refrigerant leaks."
Fernando Cabrera, for his part, also highlights the compressor as the most important component: "It is the most expensive and the one that intervenes directly so that the refrigerant flows throughout the refrigeration circuit. In the installation of ice water the outstanding components would be the pumps, which must always be in good condition for the correct functioning of the system. Another important item is the air filters, since these considerably reduce the efficiency of the equipment, if they are dirty."
On the other hand, maintenance according to the type of system has some details of differentiation, however, experts agree that the development of this phase should not be discriminated by the type of air conditioning equipment.
Engineer Botero, who is also the current secretary of the Federation of Ibero-American Associations of Air Conditioning and Refrigeration (Faiar), emphasizes, according to his experiences, that "preventive maintenance does not discriminate between large or small systems; it must be the right one for each team or part of it."
After-sales service
It is very common within the industry to hear repeated complaints about the after-sales service offered by companies. Currently, one of the strategies of the companies to achieve a better positioning in the market is to guarantee the after-sales service, and that includes the maintenance of the air conditioning systems.
When consulting Camilo Botero on this matter, his impressions were: "Complicated question." But after the exclamation he said that "I have always thought that critical maintenance should be an intrinsic issue to the company or institution that has the equipment or installation, but undoubtedly that the manufacturer or supplier of equipment has to have the specialized personnel and the appropriate spare parts to attend to the damages that the own maintenance department does not know how to solve".
Sotolongo, for his part, recommends hiring for preventive maintenance the same company that did the installation, due to how well familiar they are with the system. "It's recommended, but not essential."
Engineer Cabrera opines on the matter that "a methodology widely applied in this is that the installation companies of the systems (in the case of being a new installation) have in their items a preventive maintenance scheduled for twelve months after the system is delivered, in order to comply with the issue of guarantees in equipment components and installation of the same".
Finally, as Botero mentions: "Murphy's law in this respect is inexorable." That is, when something bad can happen, everything is given to make it happen, for that reason, it is advisable to always be very well prepared, with trained personnel, tools, procedures and manuals for any eventuality.
To highlight
Essential steps for maintenance
Although it depends on the equipment, the engineer Fernando Cabrera, consultant of air conditioning and energy efficiency, explains the most important steps to take into account for a correct maintenance of the air conditioning units:
- Visual and auditory inspection: in it the technician must observe the state of the cabinets of the machine, some type of trace of leakage, be it water, coolant, oil, etc. Some kind of abnormal noise in the installation, among many others.
- Cleaning: in this step the washing of the system is carried out, in the part of its heat exchangers, this could be done with a chemical wash if the equipment presents a strong problem due to dirt in its exchangers.
- Lubrication: in this step some parts could be greased as the bearings that merit it, although it should be noted at this point that it will basically depend on the manufacturer's recommendations.
- Parameter registration: the parameters of pressures, amperages, voltage, among others, are finally measured in order to record them in the corresponding format.
To highlight
Types of maintenance
The National Learning Service (Sena – Colombia) conducted a study based on the Labor Competence Standards in which it indicates that the main objective of maintenance is conservation through the repair, maintenance and improvement of equipment, machines and tools required by the different production systems.
The types of maintenance exposed by the Seine are classified as follows:
- Predictive or condition-based maintenance: consists of inspecting the equipment at regular intervals and taking actions to prevent failures or avoid the consequences of them. It includes both objective (with the instruments) and subjective (with the senses) inspections, as well as the repair of the defect (potential failure).
- Preventive or time-based maintenance: consists of reconditioning or replacing at regular intervals an equipment or its components, regardless of its state at that time.
- Predictive maintenance or fault finding: consists of inspecting hidden functions, at regular intervals, to see if they have failed and reconditioning them in case of failure (functional failure).
- Corrective maintenance or breakage: consists of the reconditioning or replacement of parts in an equipment once they have failed, it is the repair of the fault (functional failure), it occurs urgently or emergencyly.
- Improvement maintenance or redesigns: consists of the modification or change of the original conditions of the equipment or installation. It is not a maintenance task per se.
