What to consider before and after installing an air conditioner

First of all, you need to consider what type of unit you want and can install in your home. Whether it’s a traditional split system, which consists of an indoor and an outdoor unit; a multisplit system, with several indoor units connected to a single outdoor unit; a ducted system, ideal for large homes or full renovations; or a portable unit, which requires no installation.

Then you need to consider where to place the outdoor unit, such as a terrace, façade, rooftop, etc., always bearing in mind that it should produce as little noise as possible, especially if there are nearby neighbors.

If you live in a building with a homeowners’ association, you should always request authorization, check the statutes in case there are any prohibitions, and take into account the community regulations and the Horizontal Property Law (LPH).

In some cases, and depending on the area, you may need to request a minor construction permit from the local Town Hall. This is especially important for protected façades or historic buildings, where a special heritage permit may be required, or where aesthetic rules must be followed.

The installation must be carried out by a certified technician, as refrigerant gas is regulated by environmental law. Make sure to request an invoice and installation certificate.

Basic maintenance should also be carried out every 1–2 months by cleaning the filters; cleaning the outdoor unit at least once a year; and scheduling a professional inspection to check gas levels, pressure, and overall performance.

What types of units are there – advantages and disadvantages –

Split systems are more affordable, easy to install, and energy-efficient, but they only cool one room. Depending on the model, the number of square meters they can cool varies.

Multisplit systems, with several indoor units connected to a single outdoor unit, cool each room where an indoor unit is installed, but they are more expensive and complex.

Ducted systems are much more aesthetic and allow climate control throughout the home, but they are very costly and require construction work.

A portable unit does not require installation, and prices vary depending on brand and power, with options for all budgets. However, they are noisier and less efficient.

When talking about air conditioners with heat pumps, they not only keep us cool in summer, but we can also use the built-in heating to warm rooms in winter.

It is important that, when buying any air conditioner, it has an energy label ranging from A+++ (most efficient) to G (least efficient). An efficient unit can reduce electricity consumption by 30–50% compared to older models. Inverter systems save energy because they do not constantly switch on and off, but instead adjust their power output.

How to choose the right size (power capacity)?

It is measured in BTUs or kW, and here’s the basic rule: around 100 BTUs per square meter. For example, if a room measures 20 m², you would need a unit with 2,000 BTUs, or around 2.3 kW.

Other important factors that may influence this include: the thermal insulation of the home, sun orientation, number of windows, number of regular occupants, and appliances in use.

Many modern units now also include HEPA filters, carbon filters, or ionization systems that help reduce allergens, neutralize odors, and improve respiratory health.

What you should avoid is buying an air conditioner without correctly calculating the necessary BTUs, not consulting the homeowners’ association, installing it in a poorly ventilated or hard-to-access area for maintenance, skipping regular checkups, or ignoring condensate water drainage.

We hope this information has helped you, and now you’re ready to install your air conditioner and enjoy it.