Ducted air conditioning in Madrid: installation and maintenance
The duct system conceals all the air conditioning in the false ceiling and distributes the air to each room through grilles. No indoor units in sight, no noise in the room, with the possibility of zoning. At Uniclima, we have been designing, installing, and maintaining these systems since 2006.
In a ducted air conditioning system, the air handling unit (fan coil or duct unit) is installed inside the false ceiling or in a technical cabinet. From there, a network of galvanized sheet metal or flexible fiberglass ducts distributes the treated air to each room, where it arrives through supply grilles or diffusers. The return is done through extraction grilles connected to a return duct or via a return plenum. The aesthetic result is unbeatable: you only see the grilles on the ceiling or wall, and the equipment is completely invisible.
The perceived sound level in the room is very low because the compressor is in the outdoor unit (on the facade or roof) and the air handler is isolated in the false ceiling, away from the ear. Additionally, with a zoning system (motorized dampers + thermostats per zone), you can set independent temperatures in each room and turn off the zones you are not using, significantly reducing electrical consumption.
The essential requirement is to have a false ceiling with a free height of at least 25 cm (ideally 30–35 cm) to accommodate the air handler and main ducts. The installation cost is higher than that of an equivalent multi-split system, but in new constructions or comprehensive renovations where the false ceiling is already being built, the additional cost is significantly reduced. The entire installation is documented in accordance with the RITE (Regulation on Thermal Installations in Buildings).
Uniclima installation process
- →Calculation of supply and return flow rates per room (standard UNE-EN 13779)
- →Ductwork design: layout, sections, and pressure losses
- →Selection and installation of the air handling unit and outdoor unit (Daikin, Mitsubishi, LG, Fujitsu)
- →Execution of galvanised sheet metal or fibre ducts with thermal-acoustic insulation
- →Installation of motorized dampers and zone thermostats if zoning is required
- →Commissioning, flow balancing, and delivery of RITE documentation
Recommended maintenance plan
- →Annual: Cleaning of filters, inspection of the evaporator and condenser coils, checking refrigerant pressures, and electrical inspection.
- → Duct cleaning when appropriate according to their condition, use and maintenance schedule; deep cleaning is budgeted separately.
- →As needed: Review and calibration of motorised dampers and zone actuators, replacement of thermostats and review of the communication bus.
Mitsubishi Electric
LG
Fujitsu
Uniclima Warranty
Check applicable conditions for the equipment and contracted work: manufacturer, installation and repair do not necessarily have the same coverage. Keep the budget, invoice and documentation, without prejudice to the corresponding legal rights.
Frequently Asked Questions
How much space do I need in the false ceiling to install ducts?
You need at least 25 cm of free plenum (the distance between the upper slab and the underside of the false ceiling). With 25 cm, you can accommodate low-height flat ducts and a slim air handler. Ideally, 30–35 cm is preferred, as it allows for larger ducts — which reduces air velocity and noise — and greatly facilitates the installation work. If the available space is less than 20 cm, the duct system is not viable, and we will recommend a multi-split with cassettes or floor units.
Can I add zoning to an already installed duct system?
Yes, although it depends on the available space to access the ducts and whether they have sufficient cross-section to install the dampers. The process involves cutting the duct at each branch, installing the motorized damper, wiring the actuators, and connecting them to a centralized controller with zone thermostats. If the system was designed without considering zoning, it may be necessary to resize some sections to avoid pressure overflow when multiple zones are closed. Contact us first: we conduct an inspection of the duct condition at no obligation.
How are the ducts cleaned and how often?
The need and method of cleaning depend on the condition, material, access and use of the ducts. Before contracting, request the scope, planned means and work documentation. A single frequency should not be presented as valid for any installation.