Fried Downlights - Condensation?

[iwanttodiy]

Hi All

Just had 16 LED downlights fitted in a new kitchen extension. However 2 have fried within the space of 2 months. On pulling them out, I noticed that the diffuser/lens has a ring of water around it. I also noticed at the very top of the LED downlight, there is some cardboard/paper material and its soaking wet.

The 2 that have fried, was in exactly the same place, directly above the sink, and between the washing machine and tumble dryer. So, its quite a heavy moisture area.

Now the question is, are the downlights meant to take in some water and the ones that fried, just fried out of coincidence or is the moisture affecting and damaging the lights? I don't want to keep putting more in to find they will just burn out.

*Note* I also just noticed that this LED is installed right under a batten holding the plasterboard. I guess this batten just to happen to get in the way when the light was installed and a hole was cut out the batten to fit the LED. Could the lack of space be causing it to overheat, although its pretty draughty in the void.

 

[ericmark]

Top of a room should not suffer from condensation with the modern day requirements for insulation. There is clearly a fault some where. As to down lights and water the LED is not sealed as well as the old tungsten and it does not get hot enough to drive out water, but it does get hot enough when it cools to draw in water.

However hardly the fault of the lamps, there should not be any condensation at top of room.

 

[JohnD]

flat roof, is it?

Is this water connected to rainy weather?

Cutting holes in ceilings doesn't do them any good.

Does the extractor work?

 

[aptsys]

What's the construction of the roof for the kitchen extension? Did the downlights break the vapour barrier?

 

[Notch7]

although its pretty draughty in the void

Is it a cold roof construction -ie with the insulation just behind the plasterboard and the roof void above ventilated to outside.

I dont think cold roofs and downlighters mix well. In fact Im not keen on cold roofs full stop -difficult to create a vapour barrier that doesnt get holes put in it.

 

[iwanttodiy]

The roof is a hybrid flat roof. Grp on top -> osb deck -> 50mm celotex -> roof deck -> joists with 100-200mm of rockwool and 50mm celotex sandwiching the rockwool (essentially all voids filled with insulation) -> Tyvek airguard vapour barrier -> 30mm battons -> plasterboard.

I checked the vapour barrier it looks fine. I also don’t feel any condensation or wetness on the vapour barrier nor the top of the plasterboard.

Seems the only place with moisture that I can feel is that fried LED

 

[JohnD]

The roof is a hybrid flat roof. Grp on top -> osb deck -> 50mm celotex -> roof deck -> joists with 100-200mm of rockwool and 50mm celotex sandwiching the rockwool (essentially all voids filled with insulation) -> Tyvek airguard vapour barrier -> 30mm battons -> plasterboard.

And where multiple holes have been cut for downlighters, which layers have been cut?

 

[Notch7]

The roof is a hybrid flat roof. Grp on top -> osb deck -> 50mm celotex -> roof deck -> joists with 100-200mm of rockwool and 50mm celotex sandwiching the rockwool (essentially all voids filled with insulation) -> Tyvek airguard vapour barrier -> 30mm battons -> plasterboard.

I checked the vapour barrier it looks fine. I also don’t feel any condensation or wetness on the vapour barrier nor the top of the plasterboard.

Seems the only place with moisture that I can feel is that fried LED

I wondered because you mentioned a draught in the void -that void should be fully sealed, I wouldve thought.

Do you have underfloor heating?

 

[iwanttodiy]

And where multiple holes have been cut for downlighters, which layers have been cut?

Only the plasterboard layer. I specifically asked the plaster not to pierce the vapour barrier when cutting the hold out. I did see some grazes on the barrier which I taped up with Tyvek tape before led lights were installed. The lights are only 25mm deep so fit snuggly in the plasterboard and void.

I wondered because you mentioned a draught in the void -that void should be fully sealed, I wouldve thought.

Do you have underfloor heating?

Yes I do have underfloor heating.

I’ve added a picture of the kitchen and lights.

The lights I purchased are these from amazon. However even if they are cheap lights, they shouldn’t wet?

https://www.amazon.co.uk/Brandson-r...able&qid=1553073063&s=gateway&sr=8-1-fkmrnull

 

[Notch7]

Yes I do have underfloor heating.

I am wondering if a lack of warm air is reaching the ceiling, so where you have metal parts of the downlighters they are staying cold when the lights are off and the moist air from the sink is condensing on them because the metal temperature is below the dew point.

underfloor heating creates much less convected air compared to radiators, I had a problem in a conservatory we built for a client, they kept getting condensation on the roof glass on cold mornings. in the end they had some rads installed which helped a great deal

Im not suggesting your issue is the same, just an idea!

 

[iwanttodiy]

I am wondering if a lack of warm air is reaching the ceiling, so where you have metal parts of the downlighters they are staying cold when the lights are off and the moist air from the sink is condensing on them because the metal temperature is below the dew point.

underfloor heating creates much less convected air compared to radiators, I had a problem in a conservatory we built for a client, they kept getting condensation on the roof glass on cold mornings. in the end they had some rads installed which helped a great deal

Im not suggesting your issue is the same, just an idea!

Is your suggestion that underfloor heating could be part of the problem with condensation? And a possible remediation to install rads?

 

[EFLImpudence]

No, water vapour is the cause of condensation.

 

[Notch7]

Is your suggestion that underfloor heating could be part of the problem with condensation? And a possible remediation to install rads?

not particularly, Im just offering a suggestion as to the potential cause, not a solution.

installing rads due some fried downlighters wouldnt be the answer.

Id be tempted to change them for some white plastic downlighters instead of metal -Ive got some Aurora ones, although they are non fire rated but prob not an issue in a single storey extension (not sure about that )

https://www.screwfix.com/p/enlite-spryte-fixed-led-downlight-white-550lm-8w-240v/4476j

 

[iwanttodiy]

I think you are right. The metal casing on the LEDs is cold and thus causing condensation.

Unfortunately I had to scour the net to find these low profile downlighters, due to the lack of ceiling void.

It’s a single story extension so does not need to be fire rated. The plasterboard is just standard also.

I’ll have to rethink how I want to play this. Maybe silicone the light so vapour can’t get in?

 

[JohnD]

If the ceiling void is well-insulated, why is it cold beneath the insulation?