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Topic # 113548 20-Jan-2013 10:41 Send private message

Hi All

I am building a new house and am almost at the gibbing stage (ok so i know that means im almost too late to be asking this but i have told the sparky i have to get back to him!) and have been told LED downlights are the way to go. I am looking at using downlights for the whole house (so approx 30 of them) aside from the 4 chandeliers i am using in certain areas.

Now i have read all 33 pages of the LED lighting topic in this forum and being not in the lighting industry i dont understand all the jargon but understand the basic issue with led downlights being the loss of insulation is way more costly than energy saved using LED's.

So first question, if a get IC-F rated LED downlights, does the insulation issue go away making it worth spending $80-$150 on an LED solution??

I am looking at the below LED's:

D-Lightz
750 lumens
CRI 85
12 watts
IC-F rated
$138.75 from lighting plus

LEDLUX
600 lumens
CRI unknown
11 watts
IC rated
$67.43 from lighting direct

These two below are CA rated only but have higher lumens

D900 curve v1.5
950 lumens
CRI 95
15.5 watts
CA 135 rated
approx $150 from ECC from memory

LEDLUX LUCCI
900 lumens
CRI unknown
13 watts
CA 80 rated
$82.43 from lighting direct


So my further questions based on the above

Given i cant cover the CA rated units from above and they can only be abutted, should i completely discount them?

If so, between the 2 IC rated units, Is it worth paying double the price for an extra 150 lumens ??

I dont want hanging lights, so if downlights are still not reccomended due to insulation loss even if they are IC-F then what other options should i be looking at?

Thanks!!

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  Reply # 747709 20-Jan-2013 11:35 Send private message

I would discount the CA rated lights. I have four of the LEDLUX bulbs in my 4x3m bathroom, installed 3-4 months ago, they work well and put out heaps of light for that space, no problems at all recommending them. Once the power's on they take about 0.5 - 1 sec to blink on - they don't warm up, they're on immediately, but there is that short delay.

Lighting store said dimmable ones weren't far away so may be available now. Make sure the driver thingy is above the insulation.




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  Reply # 747764 20-Jan-2013 13:11 Send private message

I would go for the higher power CA lamps if they are closed off from the ceiling space so you do not get a draft. A quick Google suggests they are. The CA rating does not necessarily mean a draft, it means you need cooling and for LEDs that usually means the heat sink can get hot.

You need the higher power, we find ~600 lumen is borderline unless you go overboard with the number of fittings. We use 2 for bedrooms and 4 for each living space with ~600 lumen bulbs and can't wait for higher power bulbs to become wider available.

On the side, in submarines they use 40W bulbs as that is the most power where an oily rag draped over it will not catch fire. Part of the reason for not rating LEDs as IC is to do with life of the LED and electronics rather than fire safety.

I'm not keen on the D900 as it is more of a spot light than a diffused ambience light.

We have been in our new home now for over a year and have cheap incandescent Home Downlights fittings because at the time it was the only affordable thing when you have 40 lights to install. I've fitted all with Viribright bulbs which almost completely closes up the opening to the ceiling, the only openings are the gaps between heat sink fins which is not much. This has worked well during Winter when we had to use only 2x 500W oil fin heaters at a low setting to keep 160 sqm comfortable (not hot, but okay). Now we have an aircon and it seldom turns on. Next we'll install a ventilation system to pump stale air from the bedrooms to the living space so that the fresh living space air can get drawn through the passage to the bedrooms ("heat transfer" does not work for aircons, it needs a concentrated heat source, for aircons you do it reverse to "heat transfer"). Then I'll look at maybe ventilating the ceiling space during summer so it does not get so hot up there, but that is at the moment just a thought.




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  Reply # 747773 20-Jan-2013 13:36 Send private message

CA "closed abutted" aren't necessarily closed, they can be 5% open or something according to spec. That way you get a draft, and no insulation above them.

You have to trust that lights rated to be insulation covered can be insulation covered.

Also, downlights aren't necessary. I replaced most of mine with ceiling domes, each with two CF bulbs. They look good in my older house, they work well, no insulation or heating issues, and they're cheap.




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  Reply # 747820 20-Jan-2013 15:20 Send private message

timmmay: CA "closed abutted" aren't necessarily closed, they can be 5% open or something according to spec. That way you get a draft, and no insulation above them.


Correct, but a fitting rated CA does not have to be 5% open.  LED fittings are often fully closed off but still rated only CA because heat from the heat sink which is inside the ceiling needs convection to extend LED life so you cannot cover them with insulation, but there is no reason why an LED fitting would not be 100% sealed.  Incandescent bulbs need the opening for the fitting to cool down, but LEDs use heat sinks and no need for convection over the LED.

In our old house the plastic batten light fittings all changed colour and went brittle from CFL lamps, they leak UV.  One fitting had to be replaced because the electrical contact came loose from the broken brittle plastic.




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  Reply # 747824 20-Jan-2013 15:36 Send private message

LEDs in NZ are still hugely expensive and I suspect they are very high margin profit makers for the sellers. 

I believe some LED bulbs can be retrofitted into regular halogen fittings. I have been looking at some of the ones on Aliexpress, which for all I know some of these NZ retailers purchase them from anyway, as most are made in china anyway. I have thought of buying a few of something like these, just to see how well they go and last. 
http://www.aliexpress.com/item/replacement-50W-normal-one-GU10-E27-E14-GU5-3-Rotundity-CREE-Light-9W-3x3W-dimmable-High/682832739.html    Maybe not that particular one, but something similar, as there is a huge range.
I have found from personal experience that some NZ retailers sell poorly made chinese bulbs that blow / connection cracks in a very short time anyway, yet they are expensive bulbs to buy.



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  Reply # 748053 21-Jan-2013 08:19 Send private message

Thanks for the replies...


Ok so if i summarise the feedback....

I should consider more than 600 lumens as i too have a similar setup of 2 lights per room, 4 in my formal lounge/home theatre room , and 6 in my living area + kitchen.....
The LEDLUX lights are pretty good and reliable
CA rated ones are ok IF they are completely sealed.....

This basically shortlists those 4 down to the 13 W LEDLUX LUCCI 900 lumens unit....so will go for this :-)

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  Reply # 748061 21-Jan-2013 08:47 Send private message

I wouldn't consider CA rated ok. You'd be cutting 40 holes in the most important insulation in your home (ceiling), that will maybe triple the heating requirements of the house. Consumer did some testing, from memory it's something like four CA rated fittings in a room increase the heating requirements (ie your heating bill) by 250%. You can find it on their website.




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  Reply # 748074 21-Jan-2013 09:18 Send private message

So your saying even if the CA rated ones are completely closed off and 100% sealed that i should avoid them??

In that case, that only leaves the D-lightz one if i am to go with Niel's feedback that 600 lumens is borderline. I have 750 lumens will be ok then??  

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  Reply # 748097 21-Jan-2013 10:07 Send private message

A closed fitting is still a gap in the insulation. 750W is only 20% more than 600W. Are you considering ceiling domes as well as downlights?

Have a look at this chart from consumer.






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  Reply # 748286 21-Jan-2013 16:26 Send private message

Why on earth would you wish to cut holes in your perfectly insulated ceilings?  At least 25% of the light goes to illuminate the loft and the heat from the lighting units causes an updraft that draws air out of the living space and into the loft.  It's a great way to ventilate your house of course.

We have downlights because my wife insisted on them.  You could read a book up there when all the lights are on and the constant flow of warm air ensures that you wouldn't get too cold of a winter's night.

Never again!

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  Reply # 748469 21-Jan-2013 20:57 Send private message

No, the table from the consumer report is for fittings that are not sealed. It is for glass lamps which require ventilation for cooling, and CFL lamps in fittings designed for glass lamps (so still not sealed), and halogens which by design let most heat go through the diachronic reflector so needs ventilation for cooling the top of the fitting. In no way can you use that table to compare with a proper sealed LED fitting. It also ignores the fact that running the glass lamps will in itself heat up the home as a by product, a fact that all those kind of reports ignore.

When you have a CA sealed LED light fitting it is the same as if in that small area you have no insulation. But still, while the light is on it will heat up that area an amount similar to as if there was insulation. While the light is on it effectively cancels out the fact there is a small area without insulation. It is not much worse that the gaps you already have adjacent to ceiling battens where the insulation is not perfect. Yes, IC rated fittings will be better, R5 pink bats will also be better, 3m thick polystyrene walls will also be better.

Now for the statement that down lights will illuminate the ceiling space. No, it will not when you use LEDs which are inherently directional. I know, I've got exactly that. When I turn on my lights there is not enough spillage into the ceiling to see what I'm doing.

So, having set on a sealed lamp, the decision is between a questionably better insulation or more light.

If you are in (East) Auckland then feel free to PM me and come have a look.




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  Reply # 748480 21-Jan-2013 21:07 Send private message

Lights aren't always turned on. I personally insulation without holes is a must have, and I expect building regulations to catch up eventually.




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  Reply # 748579 22-Jan-2013 06:35 Send private message

The thing is you cannot seal a building, else you will get sick and/or suffocate. That is one of the reasons why windows have a breathing slot. And also heat loss through windows is (including double glazing) is worse than the tiny bit through a sealed CA fitting.

Agree requirements (which are only minimum) will get tighter, but at any one time there is a practical cut-off of what is current mainstream product vs. what is ideal. It is no use looking for a product which is not yet on the market or that is far too expensive to be practical.

The worst thermal leakage in a new home is probably the aluminium frame around double glazed windows. Even with a thermal break you still get condensation on it. The tiny hole over a light fitting is relatively small.




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  Reply # 748631 22-Jan-2013 09:34 Send private message

While everything you say makes sense, there's still the rule of thumb that even a small gap in insulation really badly affects the overall insulation. Yes ventilation is required, but it's better to be controlled than to allow light fittings to do that job.

A good heat recovery ventilation system would be ideal, in winter it gives ventilation without wasting the heat you've spent money on, and in summer it cools. You can turn it on and off as required, adjust the speed, etc.

I can't believe people are still using aluminium window. PVC is a superior material, very little heat transmission, lasts decades, costs less than aluminium with a thermal break but slightly more than basic aluminium double glazed windows. It's a no brainer, cold countries like the UK have been using PVC for decades. NZ will catch up eventually I guess.




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  Reply # 748714 22-Jan-2013 11:56 Send private message

Ventiliation was something we could not afford to do due to various reasons....however i do take the point on board that given i have spent money on upgrading the insulation, i shouldnt really be putting holes in it....

Is there any other LED downlight sold in NZ that is IC-F rated AND has greater than 750 lumens???? I dont want to risk importing online....

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