Avoiding Flicker with Dimmable Bathroom LEDs

[cedricuk]

Hi all,

 

When choosing dimmable LED lighting for a bathroom, what do you normally check to avoid flickering or an inconsistent dimming range?

 

Is it mainly a matter of matching the dimmer to the LED driver, checking the minimum load, or choosing fittings that are specifically designed to work together?

I'm also interested in whether you've found any particular compatibility issues with bathroom downlights or mirror lighting, especially when dimming at lower levels.

 

Would be useful to hear what checks have worked well in practice and what you'd recommend checking before installation.

[SteamyTea]

When you find out, come to Penzance and sort mine out.

 

https://photos.app.goo.gl/8tEXMqkJ3qaRirKX8

 

 

[Tetrarch]

21 hours ago, cedricuk said:

Hi all,

 

When choosing dimmable LED lighting for a bathroom, what do you normally check to avoid flickering or an inconsistent dimming range?

 

Is it mainly a matter of matching the dimmer to the LED driver, checking the minimum load, or choosing fittings that are specifically designed to work together?

I'm also interested in whether you've found any particular compatibility issues with bathroom downlights or mirror lighting, especially when dimming at lower levels.

 

Would be useful to hear what checks have worked well in practice and what you'd recommend checking before installation.

 

Thinking a bit laterally do you really need dimming? In my experience bathroom lighting is a binary, you either need a lot or very, very little. You could have two completely separate circuits.

 

I have a low-set LED strip in my shower niche that comes on with a PIR sensor, this is absolutely perfect for minimal nightime illumination. When more light is needed I have four LED selectable ceiling lights that I have set a 4500K but could be set to up to 6000K that are controlled by a regular switch outside the bathroom

 

Regards

Tet

[cedricuk]

23 hours ago, Tetrarch said:

 

Thinking a bit laterally do you really need dimming? In my experience bathroom lighting is a binary, you either need a lot or very, very little. You could have two completely separate circuits.

 

I have a low-set LED strip in my shower niche that comes on with a PIR sensor, this is absolutely perfect for minimal nightime illumination. When more light is needed I have four LED selectable ceiling lights that I have set a 4500K but could be set to up to 6000K that are controlled by a regular switch outside the bathroom

 

Regards

Tet

That’s an interesting approach. Having separate circuits for low-level night lighting and full bathroom illumination seems practical, especially with the PIR sensor in the shower niche. It avoids the need for dimming altogether while still giving you flexibility depending on the time of day. Thanks for sharing your setup.

[Nickfromwales]

9 minutes ago, cedricuk said:

That’s an interesting approach. Having separate circuits for low-level night lighting and full bathroom illumination seems practical, especially with the PIR sensor in the shower niche. It avoids the need for dimming altogether while still giving you flexibility depending on the time of day. Thanks for sharing your setup.

I do this in every clients bathroom and have done for 20+ years, as it’s simple, practical, and elegant. And quite ‘cool’ to have (what I always called them) some “P lights”, for nighttime automatic low level lighting.

Bathrooms are in and out rooms, so faffing with dimming is a bit daft; basic smart switches can allow you to create scenes easily and cost effectively, whilst still being ‘dumb’ single press switches.

 

Current client has rolled out Aqara for mostly lighting, and it’s a great choice for most boxes ticked and not having HA; we have done a lot of run home wiring here as we’ve opted to centralise drivers / LED running gear vs having these dotted around the home, to ease downstream troubleshooting and maintenance / repair. 

[Alan Ambrose]

In another thread on here, someone just said that trailing edge dimming works best. You could always buy one example of each light, dimmer etc and wire them up to check that they behave well.

[-rick-]

Just now, Alan Ambrose said:

In another thread on here, someone just said that trailing edge dimming works best. You could always buy one example of each light, dimmer etc and wire them up to check that they behave well.

 

The ultimate option is to choose drivers that have separate dimming control (0-10V, dali, dmx, matter, whatever). Mains dimming LED drivers is always going to be a compromise that has limitations.

 

If you are driving individual bulbs (that are designed for it) then ultimate dimming control is done via current control drivers (vs PWM). That avoids flicker and is very controllable. But it's tricky and tends to need paired bulb/driver so more likely to be found in integrated units with external dimming control.

 

Dimming LED strips or other voltage controlled devices, look for the frequency of the switching. Switching at 2000Hz is likely to be seen as flicker free to most (unless you are filming) but 20kHz drivers are available for niche uses (filming) at the cost of lower efficiency. 20khz also chosen to be above audible range as some people might be able to hear switching at lower frequencies.