Downlights And LED Retrofits In Older Ceilings

An apartment with twenty halogen downlights is running close to a kilowatt in lighting alone, and almost all of it is leaving as heat into the ceiling.

Which is why this job is worth doing, and why it is not just a lamp change.

What the old fittings were doing

A halogen downlight runs hot enough to be a genuine fire risk, which is why the rules around them were always about clearances rather than wiring.

Insulation had to be held back from the fitting. A gap had to be kept above it. Many were installed with a shield or a guard to keep batts away, and plenty were installed without one.

Over twenty years, insulation moves. Somebody goes into a roof, a batt gets pushed back into place, and it ends up sitting against a fitting that needs fifty millimetres of clear air around it. That is the condition behind most ceiling fires that start at a light.

Which means the change to LED removes a hazard, not just a running cost. That is the real argument.

Why it is not a lamp swap

There are LED lamps that fit into an existing halogen fitting, and in most older installations they are a poor answer.

The transformer stays. An old iron or electronic transformer sized for a fifty watt halogen is now driving a seven watt lamp, which it does badly. Flicker, buzz, lamps that will not start, and lamps that fail early are all transformer mismatches rather than lamp faults.

The fitting stays, meaning the same housing, the same clearance requirement and the same hole in the insulation. The hazard is unchanged.

The old fitting is not rated for close contact with insulation, so the ceiling cannot be properly insulated above it even though the heat is now trivial.

A proper retrofit replaces the whole fitting with an integrated LED unit and a matched driver.

What a proper retrofit gets you

Insulation can be laid over the top, where the new fitting is rated for it. In an apartment with a roof space above, that single change does more for summer heat and winter warmth than most other work, and it is what makes the ceiling actually perform.

Heat out of the ceiling, so the air conditioning is not fighting twenty heat sources every evening. A warm room with the lights on is partly a lighting problem, which is the same family as [a warm room and a dripping unit](/blog/a-warm-room-and-a-dripping-unit-are-one-problem).

Dimming that works, on a dimmer matched to the driver. Most LED dimming complaints are an old trailing edge dimmer driving new hardware.

Colour that suits the room. A warm white around 2700K to 3000K for living areas and bedrooms, cooler for a kitchen or a bathroom if you want it, and the same temperature throughout a room. A run of downlights at mixed colour temperatures is the most visible error in a retrofit and it happens whenever lamps have been replaced one at a time over years.

The hole size problem

The practical constraint in every retrofit.

Old halogen fittings were commonly cut at 70mm or 90mm. New LED fittings come in their own sizes, and if the new fitting is smaller than the old hole it will not cover it.

Which means either a fitting with a wider trim, a conversion plate, or plaster repair and a repaint. That is worth knowing before the job starts rather than discovering it with twenty open holes in a ceiling, and it is the reason a lighting retrofit so often becomes a plaster and paint job as well.

Where the positions are wrong

A retrofit is the moment to fix lighting that never worked.

Downlights in a grid that light the floor and leave the benches in shadow, because the layout ignored where the cupboards are. A bathroom with one fitting in the middle and a mirror that is lit from behind. A hallway with six fittings where three would do.

Moving a fitting means a new hole, a patch at the old one, and cable work in the ceiling. Which is still the right time to do it, because the ceiling is already open and the alternative is living with it for another fifteen years.

Doing it across a building

In common areas the arithmetic is stronger again, because those lights run far longer hours.

Stairwells, lobbies, carparks and corridors on halogen or fluorescent are the largest single lighting cost in a building, and the replacement also removes the lamp changes that generate half the minor callouts. The emergency and exit fittings in those areas are a separate certified system and they are dealt with in [emergency lighting and exit signs](/blog/emergency-lighting-and-exit-signs).

Ample runs LED retrofits in apartments, houses and common areas across the eastern suburbs and inner city, with the plaster repair and painting handled by one team so the ceiling is finished rather than just rewired.