How many lumens do you have in your living room?

We have chosen our lamps with E14/E27 sockets, the LED lights are available in different power levels and color temperatures and also dimmable in 3 steps. With that, we can switch from Ikea furniture assembly to orientation at 100/50/10% (without searching for the phone) and that is completely sufficient for us. The maximum value for 55m2 is about 7000 lumens.

The statement that is important to me: If you use the specification in "lumens" as a guideline in your selection, you still don’t know how bright it will be in different parts of the room. Disappointments are inevitable.

With classic light sources, 'lumens' is always taken into account regarding brightness. Ideally, with comparable geometries.

Lumens is an important measure for lighting, that’s true. Understanding its significance helps. I’ll try to make it tangible:

Lumen = luminous flux, amount of emitted light.
Candela / Lux = luminous intensity, brightness of the light (light source or reflecting surface)
Energy consumption is measured in watts; an efficiency can be calculated – lumens per watt. With incandescent bulbs there was hardly any efficiency difference, which is why power directly translated into luminous flux and, since the incandescent bulb radiates equally all around, also into brightness related to the light source. That was nicely simple!

Relationship:
When focusing a light source, the luminous flux remains constant.
The luminous intensity increases with the reduction of the illuminated area.
The luminous intensity decreases with distance (scattering losses).

This is about living room lighting – let’s take the living room table and the question of a ceiling light above it. The lumen value of the luminaire gains significance through the beam angle (let’s just leave reflector properties and diffusion panels aside for now). The technical graphic below from an Ansorg luminaire (Coray) illustrates this quite clearly:


The double FWHM angle is roughly what is generally referred to as the beam angle. The upper luminaire therefore has a beam angle of 45°, the lower one 110°.
At a distance of 2 m from the ceiling light source to the living room table, on the table surface directly below, with the upper luminaire and 1000 lumen luminous flux, a brightness of 1265 lux (candela) would be measured – that would dazzle strongly. With the lower luminaire, it would be 332 lux (still too bright).

So it’s not that simple; therefore, it is wise to work with dimmers and form an idea of what you like and what you don’t, because there are many other parameters that a good lighting planner takes into account and that not everyone wants to deal with.

We have chosen our lamps with E14/E27 sockets, the LED lights are available in different powers and color temperatures and also dimmable in 3 stages.

This is a pragmatically flexible approach: adjusting the brightness and color temperature parameters on site according to taste.

we also never want to throw away lamps because built-in LEDs fail, and the luminaires are available in various beam angles, power ratings, and light colors as well as RGB

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If you use the specification in "lumens" as a guideline in your selection, you still won't know how bright it will be in different parts of the room.
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The furnishing of the room definitely plays an important role here, bright or rather dark, smooth or rough surfaces, etc.

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This is about living room lighting - let's take the living room table and the question of a ceiling light above it.
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Here is another important point.
Certainly, two identical light sources will have a completely different effect when the light hits completely different surfaces. For example, a glossy table in one case and a matte table in another.
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And finally: when defined light sources are installed in a defined environment - a room - but there are two viewers, the judgment about the lighting can also differ. It already starts with the color temperature - which hasn't even been talked about yet :)

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It's not that simple,
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Agreed :)

Luckily, I could adjust the color temperature. My wife likes it warm and cozy. In our old one-room apartment, we had a ceiling spotlight that was never on because it was too cold and patchy. A floor lamp by the bed was enough for us. I will definitely check if the light is sufficient, but I don't want to install more lamps. So far, it has always been bright enough for all tasks. I also like the Medo 40 lamps; we have them in the hallway, bathroom, and guest WC. I have converted them all to DALI with the Osram OTI driver, and now their dimming behavior is a dream without PWM. No flickering, nothing; at night they dim to 1%, and during the day to 70%. Unfortunately, they are not available as a TW version.