Downlight Heat

Joined
19 Sep 2007
Messages
114
Reaction score
0
Location
Oxfordshire
Country
United Kingdom
Hi,

I posted a question about the recommended wattage of LED bulbs recently and the answers made me check other fittings in the house!

I've noticed that the Deta downlights in the bathroom get very hot. The bulb, holder and chrome facia are all affected. Is this normal for this type of product?

One is fitted with a Megaman 4.5W GU10 LED bulb and the other with a Kosnic 6W GU10 LED bulb. A sticker on the unit says 40W max, plus no cool beam. Weirdly the unit with the 4.5W bulb seems to get hotter than the one containing the 6W bulb.

Any advice gratefully received.
 
Joined
3 Nov 2006
Messages
26,837
Reaction score
2,875
Location
Bedfordshire
Country
United Kingdom
There are instances where a lamp holder rated at 40 Watts incandescent overheats when a much lower wattage LED lamp is used in the holder.

This may be because :-

In an incandescent lamp the majority of the heat produced in the filament is radiated into free space from the glass / quartz envelope and does not significantly heat the lamp holder

In an LED the lamp's integral driver module is in the cavity of the screw or bayonet cap of the lamp. The heat from the driver heats the cap and the lamp holder is then heated by the heat passing from the cap.
 
Sponsored Links
Joined
19 Sep 2007
Messages
114
Reaction score
0
Location
Oxfordshire
Country
United Kingdom
Thanks for that.

I've no idea where to find the recommended wattage for LED bulbs for this fitting. The only thing I know is that they were only fitted 2 years ago.

Does anyone know where I can find that information?
 
Joined
27 Jan 2008
Messages
19,709
Reaction score
1,896
Location
Llanfair Caereinion, Nr Welshpool
Country
United Kingdom
I have found there are many ways to control LED's, we call it a driver, the bit which turns AC to DC and controls the output, but it can be anything from a simple capacitor to a pulse width modulated integrated circuit used to limit current. I had a 4.8 watt 350 lumen GU10 in the kitchen, swapped for a 5 watt 500 lumen smart colour changing GU10, forget the smart capability, one is 73 lumen per watt the other 100 lumen per watt, so if not producing light it must produce heat.

As to heat limit I don't know, but I can touch most LED packages but not grip many for any length of time. Never tested degs C.
 
Sponsored Links
Joined
19 Sep 2007
Messages
114
Reaction score
0
Location
Oxfordshire
Country
United Kingdom
I can definitely touch anywhere on the unit when it's been on for a good while, but I wouldn't want to grip it for too long - although I could. This seems to match your experience so gives me confidence that it's within a normal range.

Thanks for the advice.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Top