The Domus Maxi 40 is a 1.2m suspended LED linear pendant 24W, 2400lm, 4000K atCRI90, dimmable, in a black body with a low diffuser.

Made to order, and no lead time is published

Domus asks you to call and confirm it. We will.

How many do you need? A working estimate

With 2400lm published, this can be estimated rather than guessed. The assumptions below are stated because they matter a real designneeds the room’s surfaces and geometry.

• Assumptions: a utilisation factor of about 0.5 and a maintenance factor of 0.8 ordinary values for a suspended fitting in a room of average reflectance. A dark room with exposed black structure will do worse than this, which isexactly the setting a black-bodied fitting is usually chosen for.
• So treat these as a starting count, and expect to add fittings in a darkroom.
• The 4000K version is the right one for this arithmetic 2400lm against the 3000K version’s 2160lm, for the same 24W. At 3000K you would need about one more fitting per 20m.
• Tell us the room, the ceiling height and the surfaces and we will do it properly. The point is that the input figure now exists.

And the load is trivially calculable

24W each, at exactly 20.0W/m so six is 144W andnine is 216W. The rule across every Domus linear range is total metres 20.

The published specification

Where it works

• Offices and studios planned to a lux target.
• Exposed-services and dark ceilings allow extra fittings.
• Benches and workstations.
• Retail floors CRI90 helps here.
• Not anywhere damp IP20.

Specifying it

1.2m suspended LED linear pendant. 2400lm, 24W (100lm/W), 4000K,CRI90. 120 down-only. IP20. 1200mm. 3m drop. PLEX-COB-20W strip, integral dimmable driver,DALI and emergency on request. Black body, low diffuser. 3-year replacement warranty. Order codeMAXI-40-1.2M-LD-B-4K. SKUs 3012030123. 240V. A WORKING ESTIMATE: about 6 fittings per 20m for a 320-lux general office, 9 for a500-lux drawing office or retail floor, 3 for 150-lux circulation. Assumes a utilisation factor of 0.5and maintenance of 0.8; a dark room with exposed black structure will do worse, and that is exactly where ablack-bodied fitting usually goes. Tell us the room and we will do it properly.

Supplied and supported by Lights For You.

Questions

How many will I need for an office?

About six per 20 square metres for a 320-lux general office, nine for a 500-lux drawing office or retail floor, and three for 150-lux circulation. Those assume a utilisation factor of about 0.5 and a maintenance factor of 0.8, which are ordinary values for a suspended fitting in a room of average reflectance. Treat them as a starting count rather than a design.

What would make those numbers wrong?

A dark room. The estimates assume average reflectance, and a space with exposed black structure and dark surfaces absorbs far more of the light which is exactly the setting a black-bodied fitting is usually chosen for. So expect to add fittings in that case. Ceiling height matters too, since output falls off with the square of the mounting distance. Tell us the room, the height and the surfaces and we will do it properly.

Does the colour temperature affect the count?

Yes, slightly. This 4000K version publishes 2400 lumens against the 3000K version’s 2160, for the same 24W so at 3000K you would need roughly one more fitting per 20 square metres to hit the same level. If the space wants warm light that is a fair trade; if it does not, 4000K is both the right colour and the more efficient one.

What load should I allow?

24W each at exactly 20.0 watts per metre, so six is 144W and nine is 216W. The rule across every Domus linear range is total metres times 20, which makes a mixed-length layout just as easy to calculate as a uniform one.

Is CRI90 relevant on a retail floor?

Very. At 500 lux you are lighting merchandise, and CRI90 means fabric, timber and packaging look like themselves rather than flattened the way CRI80 renders them reds in particular. Most commercial linear lighting settles for CRI 80 or better, including the Domus MAX-50 profile range, so this is a genuine advantage where stock is on display.

What is the beam angle?

120 degrees, down only. That is a wide general wash, which is what makes a row of these give an even level rather than a series of pools light spreads to roughly 3.5 times the mounting height, so at 1m above the working plane a pendant covers about 3.5m across.

Can I use it in a damp space?

No IP20, dry interior only. For bathrooms, covered outdoor areas, commercial kitchens or unsealed bays, ask us about the Domus IMPACT range at IP66 and IK10.