New build: Would you make every LED dimmable?

The title says it all… would you?

I am thinking of making all lights dimmable.

I am using 24V as supply voltage for the Meanwell drivers, and add individual LEDs to match the voltage. E.g. LED (3 x 1W or 3 x 1.2V = 3.6V); 24V - 2V drop for the driver =22V / 3.6 ~ 6 LEDs in series (on one driver)

The “dimmable” aspect allows for augmenting natural light in case the ambient light gets darker, or cloudy, etc.

Pro’s / Con’s?

Hi Max,

you may have to take a closer look at the different systems for setting up LEDs. There are CV (constant voltage, i.e. put the LEDs in parallel. The number of LEDs is limited by the wattage of the power supply) and CC (constant current, i.e. put LEDs in series).

In my experience, there are no real competitive solutions for the CC setup, so I went for CV.

Next is the decision for the LED driver and it’s control method. Apart from the power supply (i expect that’s your “Meanwell” part, at least that was the brand that I used for the power supply). The driver will determine if which control method is available. There are systems like DMX and DALI, whereas 0-10V dimmers are somewhat obsolete.

Next you would have to decide how to control and generate the appropriate dimming commands. So this could either be DMX or DALi controllers or use a gateway from in-house bus systems such as KNX. In the last year or so, some knx controlled direct drivers for LEDs have also popped up.

At the end of the day the decision of yes or no depends on the use case you expect vs the price tradeoff.

I do like my dimmable LEDs but in hindsight, we work a lot with preset scenes where the LEDs are either on (100%) or Off (0%). In two locations I have a constant light regulator in the motion/presence detectors, but this isn’t really a killer app.


Probably not all. Certain lights in my house don’t need to be dimmable. I’m thinking of lights in closets, utility rooms, garage, exterior lights, etc. I could see using them in all the living spaces though for exactly this purpose.

You also might consider whether color is something you want to control as well.

Jsut to givve you a comparison, just the lighting technology in my house (much as Rich described) dimmable lights in the living spaces, but not the utility rooms/closets and so on set me back about 5.000€ (for the roughly 90 6W 24VLED spots, fittings, 24Vpower supplies, drivers, KNX-DALI Gateway).
Probably this could have been done with just 1.000€ without dimming.

1 Like

What I strongly suggest is to use the power supply in a permanent online state and use drivers (DALI, DMX, KNX, etc.), the dimmable option is almost always present, but be aware that dimming led’s is not always the best lighting effect you can achieve while dimming! As an advice, do not switch (using relays) the LED power supply, especially when using capacitive power supplies!


1 Like

Meanwell LDD-1000H… are CC drivers, dimmable via 0-5V.
LEDs are (in principle) considered constant current driven devices.

… thanks guys… keep it coming… I am always grateful for replies… as it usually opens one’s horizon :slight_smile:

I wouldn’t bother dimming every light. Lights in spaces like wardrobes and the laundry just don’t have any need for it. In my use cases I also couldn’t see the need for it in bedrooms (bedside task lighting would be dimmed however)

OK, I re-phrase :slight_smile:
Other than closets (and other hardly visited spaces)… would you install dimmable LED lights everywhere else in a new house?

Thanks… certainly an option to think about.

While I was at it, and if cost were not too big of a concern, I might consider color lights as well. Not so much to do weird stuff like a discotec but to start the lighting off cool in the morning and gradually make it warmer as evening approaches.

Absolutely, I make everything dimmable. Of course it isn’t always needed, but then neither is home automation :wink:

  1. Theres the ‘cool’ factor of lights ramping up / down
  2. Allows flexibility for creating different moods
  3. I second Rich, changing color temperature of lights is great for accentuating natural sunlight during the day while allowing for warm light in the evening. Sunrise alarms are great too.

My lighting setup here is fully KNX with all LEDs running on 240V (G9), I´m using MDT dim actors.
I´ve set the following rooms light to be dimmable:
Living room, dining room, all bedrooms, family bathrooms and the floor there
In addition the lighting on the porch and garden.

I´ve seen you did not have bedrooms on the list but consider the following:

  • At night time I reduce the initial dimming state so that whenever someone need light at night it is a smoother transition for the eyes.

  • In the morning the light in the bed rooms does not switch from 0 to 100% directly, but is raising to fully power only within a few seconds. Much more comfortable. In general all the lights mentioned perform a soft-on/soft-off (1-2 secs), which is more pleasing to the eyes and gives a classy look :slight_smile:

  • If you have kids still little they may request a certain amount of light when going to bed. You may automatically dimm this down to zero within e.g. one hour.

  • Lights on the porch or garden tend to be to bright when it gets late - making them dimmable is a real benefit.

For all other lights I see no reason to dim them, considering security some should not be dimmable (stairs, kitchen, ground floor, guest bathroom, drive way etc).

If you are going for a new build consider switching lights centrally, e.g. with KNX - this gives the opportunity to add a dim actor later if you see that somewhere dimming is missing without the need to fiddle in the ceilings, walls or the lamps. Makes life easier.

1 Like

I am daring to revive this thread … I am back at it… this LED business did my head in then, as it does now.

Nobody mentioned any flicker when dimming the LEDs – is flickering an issue?
Also, it seems that either heaps of the same LEDs are used; we had a post with 90 x 6W or a mix, which are then dimmed via some KNX dimmer.

@george.erhan: If a relay is not a good way to switch capacitive LED drivers, how else should these be switched?

Given that I build the house only once, and do not want to make changes in the next decade or two :slight_smile: I am happy to dim in most rooms, also envisaging to install a bit more and dim it down, then not having enough.
The plan is also to augment any room with light, should the ambient light not be enough; e.g. cloudy, later in the day, etc. hence, I’d like to dim from 0 to 100 or any step in between.

Has the technology / controllers changed / improved…

I am happy to use anything that integrates with OH; be it: DMX, DALI, KNX or something else.

In case your suggestion needs to build something; I can do that too; e.g. develop a 8-port circuit board, etc.

… and a big thank you for all who have posted…

Hi Max,

The flickering might appear with low quality PWM drivers, but normally if the drivers are manufactured by companies like OSRAM, TRIDONIC, etc. the human eye can not sense it.

The power supply of the LEDS should be online at all times, the driver is just dimming or switching drawing power when needed. Of course the power supply needs to be a “smart” - standby power rating less than 0,5 W
I would definitely go for DALI - it is the cheapest and most feasible solution at the moment. KNX is also a good solution, but more expensive. If you already have KNX installed, try finding a KNX to DALI gateway (you can handle up to 64 drivers with only 1 KNX physical address) such as this. If you have RGB LEDS then DMX is the fastest way, but DALI 2.0 (RGB functions have been included in the standard) is out since end of last year and I think is cheaper.
The biggest advantage of DALI drivers is that you will have all your LEDS dimmable and switching ON/OFF will be done very nicely with soft start/stop. Furthermore you will have detailed status on working hours, deffects, etc.


1 Like

So, if I may ask, what did you use to build your system?

LEDs same wattage == same driver ==> DALI something?

I am in the process of building this, hence, I can use or am open to use anything that makes sense. :slight_smile:

Can do room sub panels… central wiring… all open at present…

Anyone else wants to chip in?! You’re welcome.

My system is KNX with DALI interface.
Depending on the LED type you should choose constant voltage DALI driver or constant current dali driver. I strongly suggest to use 24V LEDs, especially if the DC cable length or LED strip length are large (over 20-30 m)
First you need to design the power source, then the DALI driver. If you have a need for a larger power than any DALI LED driver you can find, use the smallest DALI LED driver and connect its output to the input of a an amplifier.
In terms of cable, my cabling consists of two cables (3X1,5 sqmm for power and 2X1 sqmm for the DALI bus) that are routed correspondingly to the power supplies and to the DALI drivers in a free topology but not exceeding 2kW per circuit (protected by MCCB in the electrical panel.