Spring Clean Your Air Conditioning Unit

If it’s to function at its best for the maximum possible time, an air conditioner will need occasional maintenance.

This maintenance needn’t always be especially drastic; indeed, it can often be completed in a matter of minutes, and will help to considerably extend the lifespan of the device. But even the occasional professional service will invariably prove worthwhile in the long-term.

Let’s first examine how the occasional clean might, in time, pay for itself.


During the height of summer, an air-conditioner that’s clogged with dust and whose fans are coming loose will need to expend considerably more energy than a brand new one. Even if your air conditioner was very efficient out of the box, this performance will surely be limited by the passage of time. The occasional service will help to limit this decline, and ensure that your unit uses the minimum possible amount of energy.

Guard against repairs and replacements

Fixing something that’s already broken is often a great deal more costly than preventative maintenance. What’s more, if your air-conditioner suddenly breaks down, you’ll have to live without its abilities for a few days while the necessary repairs are arranged and carried out. Often, the point of failure arrives when the unit is being pushed to its limit – typically during the height of summer. Regular maintenance will limit the chance of such an occurrence, thereby saving you money on the parts required and the labour of installing them, as well as the indirect cost your business might suffer as a result of the damage (a shop, for example, might attract less custom if it’s stiflingly warm).


Air conditioning systems are often sizeable investments, and come with accordingly sizeable warrantee so that you can have peace of mind when you make your purchase. But often warrantees come with conditions attached, which must be fulfilled if they’re to be honoured. Be sure to check your warrantee to see whether you’re required to maintain the unit – otherwise you might need to pay for any repairs yourself.

What should maintenance consist of?

Your cleaning and maintenance checklist should comprise four items: the filters, the fins, the coils and the drains. Let’s take a look at how we might care for each of them.


As the fans in your unit circulate air around the coils, they’ll also push it through a fine mesh filter, where any bits of ash, dust and oil will stick. Over time, a layer of grime will form on this filter, which will make it more difficult for air to pass through, and in turn force the fans to work a little bit harder to achieve the same level of performance. This will shorten the lifespan of the device, and increase its energy consumption.

Replacing a clogged filter with a clean one can have an appreciable impact on performance. In some cases, the improvement can be as much as fifteen per-cent. Depending on the sort of air-conditioner you have, you’ll need to either take the filter out and clean it, or replace it entirely.

This is a task which doesn’t take very long, and should be performed once every two months – and more if you have a lot of dust or pet-hair in your interior.


Attached to the coils of your air conditioner will be an array of metal fins, designed to draw heat (or a lack of it) away from the coils themselves, so that they can be blown across by the fan and thereby disperse cold (or hot) air away from the coil. Since aluminium is an excellent, inexpensive and lightweight material, it’s used for this purpose – and the fins are made as thin as possible to ensure the largest possible surface area.

Unfortunately, this means that over time the fins are vulnerable to buckling, warping and bending, which limits the available surface area, and, as a consequence, the efficiency of the fins. This can be addressed using a special ‘fin comb’, which can be purchased from air-conditioning wholesalers.


Over time, air conditioner coils will accumulate dirt. If you’ve kept your filters appropriately clean, this accumulation will be limited, but still significant. As the evaporator coils become filled with dirt, they’ll lose their ability to absorb heat. The condenser coils are at still greater risk, particularly if the exterior of your property is especially dusty, or near to trees and plants.

As part of your maintenance, be sure to clean the area around the condenser coils, leaving a few feet of space on each side in order that air can flow unrestricted around the sides. If your outdoor unit is near any deciduous trees, then be sure to get outside and clear away any fallen leaves during autumn.


Condensation in your air-conditioner, if it’s unable to drain away properly, can become a real problem. Address it by running a wire brush through your drain channels occasionally to clear any blockages.

Window seals

In the case of window-mounted air-conditioning units, it’s important to assess the integrity of the seal, which can become damaged by moisture. When gaps appear, the function of the unit can be undermined – so it’s best to pro-actively replace any damaged seals.

When should I call a professional?

Of course, while it’s advisable to perform the steps we’ve outlined here, there are a few tasks which require the skills of a professional. Checking the coolant levels, oiling motors, measuring the accuracy of the thermostat and disposing of excess refrigerant should all be left to a well-trained technician. Do this every few years to keep your unit ticking over.

In conclusion

With an air-conditioner, as with almost any appliance that’s run almost constantly, it’s better to perform maintenance little and often rather than having an enormous annual session. That way you’ll be able to ensure that you’re on top of the situation – and that filters haven’t become hugely clogged, and that coolant levels are optimal. Do the job twice a year, before the temperature peaks and troughs of winter and summer arrive. In this way, you’ll save yourself money and stress.