Once a space goes beyond a few hundred square metres, scattering stand-alone diffusers around the corners stops making sense: the fragrance never reaches every zone evenly and you end up with heavily loaded spots and others where nothing registers at all. In buildings with central air conditioning, the answer is to use the ductwork itself to distribute the scent.
When it pays off
- Large floor areas served by a single climate unit: hotels, open-plan offices, gyms, showrooms.
- Spaces where you would rather not see the hardware: with the diffuser in the plant room, there is no visible equipment anywhere in the space.
- High ceilings. A floor-level diffuser is fighting physics; the duct is already pushing air across the top of the room.
If your premises are small or have no ductwork, do not force it: a well-placed stand-alone unit performs just as well and costs less.
Which units can do it
Not every diffuser is built to work against duct pressure. The ones that are have a dedicated outlet for the connecting tube and a pump able to atomise into moving air. In the BENDIS range, the models designed for this are the ATMOS, the HALO and large-format equipment such as the NOVA.
Where the duct is tapped
The correct point is the supply duct, downstream of the air handling unit and the filter. Never on the return: from there the fragrance would go straight into the filter and the machine.
- Pick a straight run with at least half a metre clear ahead of it, so the mist can blend into the airflow.
- Drill the opening to the diameter specified in the unit's manual.
- Insert the nozzle pointing with the direction of flow, not against it.
- Seal the entry point so there are no air leaks.
This part is carried out by the building's HVAC technician or by the professional who already services the unit, since they know the circuit. We specify the point and the measurements, and the equipment arrives ready to connect.
Setting the output
With ductwork the fragrance reaches every room at once, so the setting has to be gentler than on a stand-alone unit. Always start at the minimum and programme it in time slots: opening hours plus a little before, never around the clock. And check the room closest to the machine, because that is where the heaviest load arrives.
One important detail: if the climate system is off, a duct-mounted diffuser distributes nothing. That is why it is worth synchronising the diffuser schedule with the air conditioning.
An option that leaves the duct alone
If the premises are rented and you are not allowed to touch the installation, wide-coverage stand-alone units placed along the main circulation routes are the alternative. It works well if you spread two or three units around instead of pushing a single one too hard.
Tell us the floor area and the type of building at info@bendis.es and we will tell you what suits you best. The manual for each model is on the manuals page.
