Clear, practical answers about aircon sizing, professional installation, inverter systems, electricity use, drainage, cooling faults, servicing, warranties, noise and coastal maintenance.
A reliable air conditioning system depends on more than the brand name. Correct sizing, suitable materials, proper drainage, leak testing, vacuuming, commissioning and routine maintenance all affect comfort, efficiency and long-term reliability.
This page provides general guidance. The final recommendation should be based on the room, heat load, building conditions, installation route and the requirements of the specific manufacturer and model.
Room area is a useful starting point, but the final capacity should also account for the actual heat load.
Measure the room length and width, then multiply them to calculate the floor area in square metres. The table below is a starting guide only for typical rooms with standard ceiling heights.
| Approximate Room Area | Common Starting Capacity | Typical Application |
|---|---|---|
| Up to about 15 m² | 9 000 BTU/h | Small bedroom or compact office |
| About 16–22 m² | 12 000 BTU/h | Bedroom, study or small lounge |
| About 23–32 m² | 18 000 BTU/h | Larger bedroom, lounge or office |
| About 33–42 m² | 24 000 BTU/h | Large lounge or open-plan area |
| About 43–52 m² | 30 000 BTU/h | Large open-plan or light commercial space |
| About 53–65 m² | 36 000 BTU/h | Very large room or commercial area |
The most important additional factors include:
Large glass areas, afternoon sun, flat roofs, high ceilings and limited insulation can increase the cooling load.
A bedroom, kitchen, office, server room, shop and open-plan living area can require very different calculations.
Occupants, computers, lighting, fridges and other appliances all add heat to the space.
Open doors, staircases, passages and adjoining rooms may allow conditioned air to escape.
An undersized unit may run for long periods, struggle to reach the set temperature and provide poor comfort during hotter weather. Continuous heavy operation can also increase wear and electricity use compared with a correctly selected system.
Yes. A significantly oversized system may reach the set temperature quickly and cycle more than necessary. Depending on the equipment and conditions, this can reduce comfort and humidity control. Correct sizing is better than simply choosing the largest unit available.
Send us the room dimensions, ceiling height, suburb and a few clear photos. We can advise whether a site assessment is needed before quoting.
💬 WhatsApp My Room DetailsA proper installation protects performance, drainage, appearance and long-term reliability.
A back-to-back installation normally places the indoor unit on the inside of an exterior wall and the outdoor unit on the opposite side of that same wall. The short pipe route usually makes this the neatest and most cost-effective standard installation, provided the position suits drainage, airflow, access and manufacturer clearances.
A straightforward wall-mounted back-to-back installation often takes approximately 3–5 hours. Longer pipe routes, difficult wall construction, height work, roof access, condensate pumps, trunking, electrical work or restricted access can extend the time.
The materials depend on the model, route and mounting position. A quotation may include:
Vacuuming removes air and moisture from newly connected refrigerant pipework before the service valves are opened and the system is commissioned. Moisture and non-condensable gases can interfere with operation and contribute to reliability problems.
Wall-mounted air conditioners normally use a gravity-fed drain, which allows condensate water to flow away through a correctly sloped pipe. When the drain cannot fall continuously to a suitable discharge point, a condensate pump may be required to lift or move the water.
Pumps add cost, contain moving parts, may produce some operating noise and need periodic inspection and cleaning. For that reason, a reliable gravity drain is preferred whenever the building layout allows it.
Airsense fits PVC trunking on most exposed outdoor pipe runs where it is practical and included in the quotation. It protects the installation and gives the pipework, cable and drain a neater finish. Colour coding or painting can be arranged on request and may carry an additional charge.
Airsense provides a standard 1-year workmanship warranty on work performed by us, subject to the written quotation and terms. It is intended to cover a verified defect directly caused by our installation or repair workmanship within the agreed scope.
It does not replace the manufacturer’s product warranty and does not normally cover manufacturing defects, normal wear, dirty filters, blocked drains caused by lack of maintenance, corrosion, power-supply problems, misuse, accidental damage, third-party alterations, pre-existing faults or work and materials not supplied by Airsense.
Manufacturer warranties vary by brand, model, component and supplier. They generally relate to qualifying manufacturing defects in the equipment or specified parts during the stated warranty period.
Registration, proof of purchase, professional installation, correct commissioning and maintenance records may be required. Labour, travel, refrigerant, consumables, corrosion, power surges, incorrect use, lack of maintenance and installation-related faults may be excluded unless the written warranty specifically includes them.
Poor cooling does not automatically mean the system needs refrigerant. Proper diagnosis should come first.
Possible causes include:
A technician should test the system rather than replacing parts or adding refrigerant based on guesswork.
Refrigerant circulates inside a sealed system and is not a fuel that should be consumed during normal operation. If the charge is low, there may be a leak, a previous repair issue or an incorrect initial charge.
Common causes include:
Switch the unit off if water is reaching electrical components or damaging ceilings, walls, floors or furniture, then arrange an inspection.
Ice can form because of restricted airflow, dirty filters or coils, an indoor fan problem, sensor issues, low refrigerant charge or operating conditions outside the unit’s intended range. Turn the system off and allow it to defrost before inspection. Do not force ice off the coil because the fins and tubing can be damaged.
Tell us the brand, model, symptoms, error code and suburb. Photos or a short video can help us understand the problem before booking.
💬 Request Repair AssistanceCleaning and inspection intervals should suit the model, environment and amount of use.
Many residential systems benefit from a professional inspection and service approximately once a year. Units used heavily, installed near the coast or operating in offices, shops, gyms, kitchens, server rooms or dusty environments may need attention every 3–6 months.
The correct interval depends on usage, conditions and the manufacturer’s maintenance requirements.
A Deep Clean Major Service goes beyond washing the removable filters. Depending on the unit design, condition and access, it may include controlled dismantling and cleaning of the evaporator coil, blower wheel, drain tray, drain line and accessible internal surfaces.
This type of cleaning can improve airflow, reduce dirt-related odours and help the system operate more effectively when contamination is the cause of poor performance. It does not repair failed parts, refrigerant leaks or electrical faults unless those items are separately diagnosed and approved.
View our Deep Clean Major Service page for the current scope and booking information.
Most washable indoor dust filters should be checked regularly and cleaned when visibly dirty, following the instructions for your model. Allow washable filters to dry before refitting them. Do not operate the unit without its filters unless the manufacturer specifically instructs otherwise.
Filter cleaning does not replace professional servicing because the coil, blower, drain system, outdoor unit and electrical components may also require inspection.
Inverter systems can vary compressor speed to match the load instead of operating only fully on or fully off. This often improves part-load efficiency, temperature control and noise, especially when the unit is correctly sized and used for longer periods.
Actual electricity use still depends on the model’s efficiency rating, capacity, room heat load, set temperature, outdoor conditions, maintenance and operating time. Compare the official specifications of similarly sized models rather than relying on the word “inverter” alone.
| Inverter System | Fixed-Speed System |
|---|---|
| Compressor speed can modulate with demand. | Compressor generally cycles on and off at fixed capacity. |
| Often provides steadier room temperature. | Temperature variation may be more noticeable between cycles. |
| Can be quieter after the room approaches the set point. | Starting and stopping may be more noticeable. |
| Usually higher purchase price and more complex electronics. | Often lower upfront cost and simpler control design. |
Start with the unit’s rated electrical input in kilowatts, not its cooling capacity in BTU/h. A simple estimate is:
An inverter unit’s input changes while it operates, so the nameplate maximum or rated input is not necessarily the average consumption. Room conditions, thermostat setting and cycling also affect the result.
There is no guaranteed lifespan. As a broad planning estimate, many systems provide roughly 10–15 years of service, but actual life can be shorter or longer. Installation quality, operating hours, maintenance, coastal corrosion, power conditions, availability of parts and repair history all make a difference.
Salt-laden air can accelerate corrosion of outdoor coils, cabinets, fasteners and electrical components. Select a suitable model, maintain required airflow clearances, inspect the unit regularly and follow the manufacturer’s coastal maintenance instructions.
Some models include factory-applied anti-corrosion treatments. Additional protective coating may also be considered where suitable. No coating makes an outdoor unit corrosion-proof, and ongoing maintenance remains important.
Ask Airsense about Bluchem anti-corrosion treatment when planning an installation close to the sea.
Knowing the main components and ratings makes it easier to compare systems and recognise possible faults.
New or increasing noise may come from loose panels, vibration, an unbalanced blower wheel, worn fan bearings, debris, pipework touching the building, poor mounting, a condensate pump or a mechanical fault. Some airflow and compressor noise is normal, but rattling, grinding, screeching or heavy vibration should be inspected.
The compressor circulates refrigerant and raises its pressure so the refrigeration cycle can move heat between the indoor and outdoor units. Compressor faults can stop cooling or heating, but electrical supply, controls, sensors and fan problems must also be tested before condemning the compressor.
The outdoor unit usually contains the compressor, outdoor heat exchanger, fan and electrical or electronic components. In cooling mode it rejects heat collected indoors. In heating mode, a reverse-cycle unit uses the same refrigeration system in the opposite direction.
These are efficiency measures used under different test methods. EER compares cooling output with electrical input at specified conditions, while seasonal measures such as SEER or CSPF are intended to represent performance across a range of operating conditions.
A higher value generally indicates better tested efficiency when comparing the same rating method and similar equipment. Do not compare unlike ratings as though they are identical.
A reverse-cycle heat-pump air conditioner can provide both cooling and heating. Not every air conditioner has heating mode, so check the model specifications. Heating performance and electricity use depend on sizing, outdoor temperature, building heat loss and the unit’s efficiency.
Repair is often sensible when the unit is in reasonable condition, parts are available and the repair cost is proportionate to the remaining value of the system. Replacement may offer better value when the unit is old, badly corroded, repeatedly failing, inefficient, using obsolete components or facing an expensive major repair.
Airsense serves residential and commercial customers across many parts of Cape Town, including the Southern Suburbs, Northern Suburbs, Atlantic Seaboard, City Bowl, CBD and surrounding areas. Availability and travel charges depend on the suburb, job type and schedule.
Direct involvement, clear communication and personal accountability.
Professional testing, vacuuming and commissioning instead of guesswork.
Hands-on installation, servicing, maintenance and repair experience.
Recommendations based on the system, site conditions and approved scope of work.
Contact Airsense for installation assessments, fault finding, repairs, servicing, Deep Clean Major Services and planned maintenance in Cape Town.
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