How much ceiling height does ducted air conditioning take?
A slim ducted unit needs roughly 25 to 30 cm of free height above the suspended ceiling where it sits, and the ducts in other rooms need 12 to 18 cm. The unit is normally hidden over the corridor, bathroom or dressing room, so the living room and bedroom keep almost their full height.
That is a rule of thumb; the data sheet of the specific model decides. Unit depth is counted together with insulation, hangers and the gap needed to pull out the fan. In an Eixample flat with 3.2 to 3.5 m ceilings, losing 30 cm in the corridor is barely noticeable; with 2.6 m in a new build, the same unit already suffocates the space, and then mini-duct models or other schemes come into play.
Where does the indoor unit hide and how do you reach it?
The unit goes where the ceiling can drop without harming rooms: corridor, hall, bathroom, utility room, dressing room. It does not go over a bedroom, which is the main cause of night noise.
The suspended ceiling needs an access hatch under the unit, normally at least 60 by 60 cm, with free reach to the filter and fan. In a luxury interior the hatch is made invisible: flush and painted to match the ceiling, or replaced by a linear return grille through which the filter is changed.
In the 250 m2 children's psychology centre in Eixample, the project included climate control with heat recovery, and the routing through the ceiling void was solved together with the hatches and the hidden doors. A home is simpler, but the principle is the same: hatches and routes first, finishes after.
Which grilles replace the standard ones?
In high-end interiors linear slot diffusers are used, with a slot 20 to 30 mm wide and from a metre long, set flush into the plasterboard. Filler and paint are finished up to the frame so that a thin shadow is left instead of a grille.
The diffuser is chosen by airflow, not by looks. If the slot is short, outlet speed rises, whistling appears and the air feels like a draught on the shoulders. Supply is directed along the wall, not at the bed or sofa. Return air is handled separately, in the corridor or through a door with a ventilated lower part; otherwise a closed bedroom door creates a pressure difference.
Grille and profile colours are agreed with the ceiling colour in advance, not at handover.
Can each room have its own temperature?
Yes, if the system is zoned: the duct to each room carries a motorised damper and its own thermostat. There is one unit supplying air at one temperature, and the dampers decide how much each room receives.
This arrangement has a limit. If almost all zones close, duct pressure rises, air whistles at the grille that stays open and the unit runs unstably. So a bypass damper is designed in, or a minimum flow is left to each zone. For a home with two very different regimes, say day and night, it is sometimes more sensible to split it into two systems.
Capacity is calculated from the sum of heat gains with a margin for the hottest days. An oversized unit starts in bursts, dehumidifies worse and wears out sooner, so doubling it up is not a safety measure.
Is a ducted system noisy at night?
With a good design, a bedroom hears only a light whisper of air: the benchmark is 25 to 30 dB(A). Noise comes from the unit fan, air speed at the grille and vibration carried into the ceiling.
Several measures remove it. Speeds in ducts and at the outlet stay low, around 2 m/s at the grille. Silencers go on the run towards the bedroom, with insulated flexible ducts instead of long rigid runs. The unit hangs on anti-vibration mounts, not rigid rods, and never over bedrooms. The route between rooms has bends, not a straight pipe: a straight pipe carries conversation from room to room.
The remote's night mode lowers fan speed, but it does not replace a good route.
Where does the condensate go and how is the system maintained?
Condensate drains to the sewer through a trap with a fall of at least 1 percent; if a fall is impossible, a condensate pump with a safety sensor is fitted. An extra drip tray goes under the unit so a leak does not ruin the ceiling.
The filter is cleaned every two or three months in season, and it must be reachable without climbing on a table. The outdoor unit and the refrigerant line are agreed beforehand; what can go on a facade and how to apply is described in our article on air conditioning on facades, and in listed buildings the scheme is different.
Refrigerant lines are run in sleeves before the walls close, because afterwards you have to chase into a finished surface.
How can BCN YARD help with climate in a home?
Climate control is designed together with the ceilings, lighting and furniture, because they share the same volume overhead. We visit the home, measure the height and assess where the unit can really be hidden, then prepare the estimate. We work with our own crew and trusted subcontractors, one person is responsible for the site, and we speak Russian and Spanish.
Frequently asked questions
How many centimetres of ceiling does ducted air conditioning need?
A slim ducted unit usually needs 25 to 30 cm above the suspended ceiling where it sits, and 12 to 18 cm for the ducts in other rooms. The unit hides over the corridor or bathroom, so living room and bedroom hardly lose height. The data sheet of the chosen model gives the exact figure.
Can each room be controlled separately?
Yes, if the system is zoned: each duct has a motorised damper and its own thermostat. There is one unit and a common supply temperature; only the airflow changes. If nearly all zones close, the system gets noisy, so a bypass or a minimum flow is designed in.
Does ducted air conditioning make noise at night?
With a correct calculation, a bedroom hears a whisper of around 25 to 30 dB(A). Noise depends on air speed at the grille, the unit's anti-vibration mounts and silencers on the run. The unit is not placed over a bedroom and outlet speed is kept around 2 m/s.
Where does the condensate of a ducted unit go?
To the sewer through a trap with a fall of at least 1 percent. If that fall is not possible, a condensate pump with a safety sensor is fitted. A tray goes under the unit so a leak does not damage the ceiling. All routes are planned before ceilings and walls close.