Cooling without an outdoor unit on the facade: options for listed buildings

How do you cool a flat in a protected building if no unit may go on the facade?

The outdoor unit moves to somewhere out of sight from the street: the roof, an enclosed inner courtyard or a ventilated niche on the terrace. Inside the flat you install a ducted system or water fan coils. Another route is a through-wall monobloc with a grille, but in protected buildings it needs a separate permission and is usually less efficient.

All the options come down to three questions: what the building's protection allows, whether the comunidad agrees and how many metres of line the equipment tolerates. The facade rules and procedure are covered in our article on air conditioning on facades; here we go deeper into the technical side.

Can the outdoor unit go on the shared roof?

It can, if the comunidad agrees, because the roof is common property. In practice that is a vote by the owners and usually a regulation of the space: who installs what, where, on what conditions, how the line is run and who answers for the waterproofing.

It works well when the owners adopt one regulation for everyone. Units sit on a common frame with vibration isolation, lines rise through shafts agreed in advance and the roof membrane is not drilled: supports stand on pedestals. The documents owners usually ask for are explained in our article on comunidad authorisation for works.

The real limit is not permission but physics: the closer the flat is to the roof, the shorter the line; on lower floors you have to solve how refrigerant and condensate get through the whole building.

What about the inner courtyard: may a unit go there?

Units go in courtyards more often than on facades, but a courtyard is not rule-free. In a courtyard every window facing it hears the unit, so noise becomes a matter of neighbourly relations and municipal noise rules, not only of looks.

So the question does not stall, three things are checked before buying equipment. What the building statutes and meeting minutes say. Whether the building's protection admits a courtyard position when it is visible from neighbouring buildings. And what the real sound power of the unit is: choose a quiet model, not the cheapest. Units on anti-vibration mounts, with condensate drainage and no airflow towards neighbours' windows get consent far more easily.

If the courtyard is small and has many windows, it is better to take the unit higher, onto the roof.

How efficient are air conditioners without an outdoor unit?

The term covers monoblocs whose compressor sits inside the flat and which take in and expel air through two holes of about 16 to 20 cm in the outer wall. There is no unit on the facade, but the grilles remain.

In energy efficiency they usually sit one or two classes below an ordinary split, sound louder in the room and take floor or wall space. In a protected building they have another problem: two holes in the wall affect exactly the facade you wanted to respect, and they are processed separately. The grille is painted the colour of the wall and fitted flush, but the decision stays with the competent body.

A monobloc is reasonable for a single room with no other way out, but for a whole flat with high ceilings it falls short.

Which systems cannot be seen from the street at all?

Those that leave nothing outside the flat. That means a ducted system with its unit on the roof, fan coils with a water chiller in the courtyard or on the roof, and central schemes with one water loop for the whole building.

Water systems cost more and are more complex. The roof chiller produces cold water that travels through pipes to the flats, where fan coils or duct coils work. There is nothing outside the flat and line length is barely limited, because the pipe carries water, not refrigerant. The scheme needs a building-wide design and the comunidad's agreement, but it solves the issue for good and for every floor.

With a tighter budget something simpler works: a unit on the roof and a refrigerant line up an existing shaft.

How long can a refrigerant line be, and what other limits exist?

Maximum length and height difference are in the equipment data sheet, and in an old building with a four or five floor shaft they often become the main limit. The longer the line, the less capacity arrives and the harder oil return to the compressor becomes.

On long runs you choose equipment with margin and calculate the refrigerant circuit for that particular building rather than fitting a standard kit. Condensate is drained separately, to the sewer, not dry down the shaft. Outside noise is limited by common sense and the city's rules, so the unit sits on anti-vibration mounts and sound pressure is estimated at the nearest window.

The takeaway for the project: routes and equipment positions are agreed and allowed for before the walls close, or a finished renovation has to be broken open.

How can BCN YARD help with climate when the facade is off limits?

We visit the site, look at the building, shafts, roof and courtyard, and help you choose a scheme that can actually be approved. Paperwork and the comunidad process can be run in Russian and Spanish. We work with our own crew and trusted subcontractors, one person is responsible for the site, and the estimate is prepared after the visit and measurements.