Circadian Bathroom System with a Tunable Mirror in Matt White

A bathroom that changes with the day: the mirror tunes with the room, so a face is lit at 5000K for shaving in the morning and 2700K for the last look before bed.

Bathroom lighting is the one part of a house where getting it wrong is a safety matter rather than a taste matter, and it is sold almost entirely on photographs. Every listing here states the zone the fitting may be installed in, the IP rating with both digits explained, the colour rendering index, the lumen output and the efficacy in lumens per circuit watt. If a fitting is not suitable above a bath we say so on the page you are buying it from. If a mirror is backlit and will not light your face, we say that too.

Specification

• Zone: zones 1 and 2 and outside the zones, which is every position in a domestic bathroom except inside the bath itself
• IP rating: IP65. Dust tight, and protected against low pressure water jets from any direction. This is the rating for zone 1, which is directly above a bath or in a shower
• Dimensions: six IP65 downlights at 85mm cut out plus the mirror or mirror light listed, and a wall controller at a single gang back box
• Light output: 3900 lumens at full daylight and 1 lux on the night circuit, at 86 lumens per circuit watt
• Colour temperature: 1800K amber on the night circuit through 2700K in the evening to 5000K at seven in the morning, on a schedule you set once
• Colour rendering: CRI 95, measured, with R9 above 60. R9 is the deep red value and it is the one that decides whether skin looks like skin. Most bathroom fittings quote a CRI in the eighties and do not quote R9 at all, which is how you end up shaving by a light that makes you look ill
• Dimming: 0 to 10V on the day circuits, driven by the controller, dimming smoothly to 0.5 per cent with no visible step
• Electrical: Class 2 drivers, one 0 to 10V controller at a single gang back box, and no neutral required at the switch
• Fire rating: fire rated to 30, 60 and 90 minutes, tested to BS 476 Part 21 in both plasterboard and timber joist constructions, and the test certificate is downloadable from this page
• Standards: BS EN 60598 for luminaires, BS EN 62471 photobiological safety at the exempt group, BS EN 55015 for electromagnetic emissions, UKCA and CE marked
• Weight: approximately 27.8 kilograms
• Guarantee: seven years on the fitting, the LED module and the driver
• Finish: a powder coated matt white that disappears into a ceiling, and the cheapest honest finish we stock
• Control: on the wall. No app, no account, no cloud service to be discontinued. The schedule is set with three buttons and it stays set through a power cut
• The night circuit: 1800K at 1 lux at floor level, which is enough to see by and low enough not to reach the melatonin suppression threshold
• The science, briefly: the retinal cells that set the body clock respond most strongly around 480 nanometres, which is why an amber night light matters and a bright white one at 3am does not just wake you, it shifts you
• Schedule: set once, and it follows sunrise and sunset by date rather than running fixed clock times

What arrives

• six IP65 downlights
• the mirror or mirror light listed
• the amber night circuit fitting
• the wall controller and back box
• drivers and IP65 connectors
• a reflected ceiling plan
• a one page setup card

Installation

A registered electrician, most of a day, and the 0 to 10V control cable has to be run alongside the switch drop. Electrical work in a room containing a bath or a shower is notifiable under Part P of the Building Regulations in England and Wales. That means it has to be done by a registered electrician or signed off by building control. Replacing a like for like fitting on an existing circuit is not notifiable. Adding a new circuit, a new socket or a new spur is. Setting the schedule takes about five minutes with the card supplied and is done once.

Choosing between this and the alternatives

The reason to do this in a bathroom rather than a bedroom is that the bathroom is where the bright light happens. Somebody who gets up at three in the morning and turns on six 650 lumen downlights has just given themselves a dose of light that will hold the body clock awake for another hour. An amber circuit at 1 lux does the same practical job and does not. That is the whole argument, and it is worth more than the sunrise feature that gets the photographs.