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Topic # 87436 28-Jul-2011 21:10
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I've worked out why my office cools down so quickly - I have four downlights that have insulation nowhere near them. Does anyone know if I can get downlights that will fit into the same holes that can have insulation above and beside them?

The ceiling is really thin, not one a person can get into, just the ceiling, wood to hold it up, and roofing iron, with insulation in there. It's a lowish ceiling, I probably wouldn't want ceiling domes in there. The outer diameter is 95mm. To get insulation in i'd probably just have to take the fitting out, stuff the insulation in, the have an electrician install new lights.











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  Reply # 499146 28-Jul-2011 21:59
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if you can cut a larger hole, say 105mm, then standard screw bulb (es) down light fittings will work. The catch is to make sure there is enough airflow around the lamp (between fitting and lamp), and that the lamp is a power saving bulb as it does not produce anywhere the amount of heat a standard lamp does.

To make the light fitting comply with electrical standards, a sticker or such needs to be clearly displayed stating that the fitting must only use energy saving lamps due to heat.

This way, insulation can be put directly on top or around the fitting.

The best thing is to go see your local lighting supplier and chat to them about the appropriate fitting.


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  Reply # 499158 28-Jul-2011 22:37
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freitasm: You want Fozz lights (www.fozzlighting.com available from www.lightingdirectdesign.co.nz). The recessed ones (LED and CFL) have the certification for this.


Yeah those are the ones I remembered you talking about, thanks Mauricio.

$65 each though... four lights... $260 plus the cost of an electrician. Is there a cheaper way to achieve the same kind of thing? Like I said the ceiling's low - i'm 5'6" and I can almost touch it on one the low side, so any fitting that wasn't recessed would have to be really slim.




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  Reply # 499159 28-Jul-2011 22:37
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timmmay: I've worked out why my office cools down so quickly - I have four downlights that have insulation nowhere near them.

Consider testing your hypothesis before starting work. If you believe the cause is simple air convection loss into the cavity (I'm guessing) first remove bulbs to make safe and block the area with cardboard or something else which will not damage your ceiling finish and see if this improves the situation. Although you will notice, it would be interesting to measure the difference somehow as well.



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  Reply # 499160 28-Jul-2011 22:39
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gzt:
timmmay: I've worked out why my office cools down so quickly - I have four downlights that have insulation nowhere near them.

Consider testing your hypothesis before starting work. If you believe the cause is simple air convection loss into the cavity (I'm guessing) first remove bulbs to make safe and block the area with cardboard or something else which will not damage your ceiling finish and see if this improves the situation. Although you will notice, it would be interesting to measure the difference somehow as well.


Well that is an excellent idea. I have floor standing lamps I use 99% of the time, honestly the ceiling lights are rarely even used. I could quite easily (I presume) take them out, stuff in some insulation, tape the power switch so it can't be turned on, and see if the room uses less heating over the course of a few evenings.

Thanks to JJ for his thoughts too.




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  Reply # 499170 28-Jul-2011 23:23
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timmmay: I could quite easily (I presume) take them out, stuff in some insulation, tape the power switch so it can't be turned on

Stuffing in insulation might have a couple of disadvantages. Insulation will slow, but may not entirely stop air convection into the cavity. For your test you need to block the air movement to achieve that 100%. Also, it may be difficult to get the insulation out again if you want to. Once you stuff insulation in there, you are more or less making the decision to install the new lighting system if you can't get the insulation out. 

Looking at the fitting design you should be able to get away with sticking rings of thick cardboard directly onto the fitting with a blu-tack seal. Still remove the bulbs to avoid potential family/flatmate accidents.

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  Reply # 499175 28-Jul-2011 23:34
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You do have heat cans on those lights don't you? If you do, you can often have the insulation up to the heatcan. You also maybe able to get LED downlights cheaper if you shop around, especially with the good exchange rate.

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  Reply # 499199 29-Jul-2011 00:56
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you can run the insulation right up to the fitting if you have light/heatcan with the CA (closed abuted) rating. not all light fittings + heat cans are rated for that, and if you have a fire - your insurance might be null+void if you havent followed the building code.

i have the following recessed halogens installed with the heat cans which gives them a CA rating. Each fitting + heat can was quite cheap, i think: http://www.prolux.co.nz/products.php?pa=detail&content_id=273

next time i build/renovate, i'd probably steer clear of recessed halogens in favour of something that doesnt sacrifice insulation.




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  Reply # 499200 29-Jul-2011 01:03
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Regs: you can run the insulation right up to the fitting if you have light/heatcan with the CA (closed abuted) rating. not all light fittings + heat cans are rated for that, and if you have a fire - your insurance might be null+void if you havent followed the building code.

i have the following recessed halogens installed with the heat cans which gives them a CA rating. Each fitting + heat can was quite cheap, i think: http://www.prolux.co.nz/products.php?pa=detail&content_id=273

next time i build/renovate, i'd probably steer clear of recessed halogens in favour of something that doesnt sacrifice insulation.


From my experience recessed halogen lights are a PITA, as they regularly blow, and the pin fittings can be temperamental, and there are problems with insulation. Pendant lights are good, but you need a higher stud for them to look good. Surface spots are also good.

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  Reply # 499201 29-Jul-2011 01:03
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also, if you switched for LED instead, you dont necessarily have to replace your fittings. You can get "LED Halogen Replacement" bulbs which you can plug straight in instead of a halogen bulb

e.g.
http://www.nzlightingltd.co.nz/shop/LED+Lights++Lighting/LED+Bulbs.html
http://www.trademe.co.nz/Home-living/Lamps/Bulbs/auction-395356368.htm
http://www.trademe.co.nz/Home-living/Lamps/Bulbs/auction-394625633.htm




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  Reply # 499238 29-Jul-2011 09:10
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Does anyone know how to get these fittings out of the ceiling? I think they're probably attached with clips, but I guess you don't just pull them, it may take the ceiling with it.

Also, are there any really slim line fittings that sit underneath the ceiling? That way I could just stuff the ceiling with insulation and hang a light underneath.

gzt:
timmmay: I could quite easily (I presume) take them out, stuff in some insulation, tape the power switch so it can't be turned on

Stuffing in insulation might have a couple of disadvantages. Insulation will slow, but may not entirely stop air convection into the cavity. For your test you need to block the air movement to achieve that 100%. Also, it may be difficult to get the insulation out again if you want to. Once you stuff insulation in there, you are more or less making the decision to install the new lighting system if you can't get the insulation out. 

Looking at the fitting design you should be able to get away with sticking rings of thick cardboard directly onto the fitting with a blu-tack seal. Still remove the bulbs to avoid potential family/flatmate accidents.


Good point about not being able to get insulation out. From my quick look I suspect they're abutment rated, or at least the insulation has been abutted. Given I could touch insulation when I took a bulb out I also doubt there are any heat cans.

It's not just air movement i'd be trying to stop with a test though, it's also stopping the heat going straight out through the non-insulated areas.


mattwnz: You do have heat cans on those lights don't you? If you do, you can often have the insulation up to the heatcan. You also maybe able to get LED downlights cheaper if you shop around, especially with the good exchange rate.


I don't think so. I looked into cans and LED lights when I was replacing downlights in my lounge, my information/conclusion was the fittings still generate heat and putting cans over them isn't a great idea. Same with LED lights, less heat but still some. You can't just insulate over any fittings.

Regs: you can run the insulation right up to the fitting if you have light/heatcan with the CA (closed abuted) rating. not all light fittings + heat cans are rated for that, and if you have a fire - your insurance might be null+void if you havent followed the building code.

i have the following recessed halogens installed with the heat cans which gives them a CA rating. Each fitting + heat can was quite cheap, i think: http://www.prolux.co.nz/products.php?pa=detail&content_id=273

next time i build/renovate, i'd probably steer clear of recessed halogens in favour of something that doesnt sacrifice insulation.


Interesting. I'll talk to my electrician.

Regs: also, if you switched for LED instead, you dont necessarily have to replace your fittings. You can get "LED Halogen Replacement" bulbs which you can plug straight in instead of a halogen bulb

e.g.
http://www.nzlightingltd.co.nz/shop/LED+Lights++Lighting/LED+Bulbs.html
http://www.trademe.co.nz/Home-living/Lamps/Bulbs/auction-395356368.htm
http://www.trademe.co.nz/Home-living/Lamps/Bulbs/auction-394625633.htm


As above, i'm not sure that's true. Maybe with an LED bulb and heat cans I could in practice insulate over them, but i'm not sure about insurance. I'd definitely rather pay $250 than potentially void my insurance.




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  Reply # 499268 29-Jul-2011 10:37
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timmmay: It's not just air movement i'd be trying to stop with a test though, it's also stopping the heat going straight out through the non-insulated areas.

If you could see insulation when you took them out, it is likely the insulation is fairly close to the fittings anyway. If you are losing the ceiling layer of hot air through those fittings - it is likely a much bigger and more noticeable effect than a small patch of non insulated area around the fittings themselves.

I have to agree about led replacement and then insulating over being a potential danger later on.



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  Reply # 499273 29-Jul-2011 10:43
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gzt:
timmmay: It's not just air movement i'd be trying to stop with a test though, it's also stopping the heat going straight out through the non-insulated areas.

If you could see insulation when you took them out, it is likely the insulation is fairly close to the fittings anyway. If you are losing the ceiling layer of hot air through those fittings - it is likely a much bigger and more noticeable effect than a small patch of non insulated area around the fittings themselves.

I have to agree about led replacement and then insulating over being a potential danger later on.


I could touch it on one side, on the other side there was a big gap, I couldn't touch the insulation. Consumer magazine found that (from memory) having four downlights with abutted insulation the heating requirements for the room were doubled - ie double the power usage. With eight it was something like 2.5 times.

Apparently even small gaps in insulation make a huge difference, which is why I replaced the lights in my lounge. It's also why i'll probably spend another couple of hours up in the ceiling with a skill saw this weekend, cutting holes so I can get in to make sure my ceiling insulation in the body of the house is placed well, without gaps.




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  Reply # 499296 29-Jul-2011 11:00
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LED lamps would be perfect except that they are expensive for quality ones, ie right colour light.

As I said before, the cheapest option would be:

Bunnings 105mm ES downlight in white -$8.85 with Halogen lamp (just throw away lamp)
15-24watt es power saving [CFL] philips lamp from $6-$9.

These puppies wont get any where near as hot as CA rated halogen downlight fittings, therefore you can also put insulation over top.

[edit] the haolgen lamp mentioned above is not the 12volt small halogen kind, but the power saving version of a normal 100watt lamp. 

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  Reply # 499303 29-Jul-2011 11:05
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Just googled for that consumer article. The main conclusion is: "Recessed downlights waste energy by sucking warm air from your living area into the roof space".

Insulation or lack of it is very far from the main factor.

If cans slow heat loss, most of the benefit will come from slowing air movement into the cavity. [same with  systems designed to be insulated over]

And from rightlight: "Most recessed downlights have large ventilation air-gaps that keep the light bulb (and your house) cool, by venting warm air from your living areas into the roof space. "Little chimneys” - as downlights are known in energy-efficiency circles - could be robbing you blind"

[Edit: the rightlight article is actually the consumer one reprinted on one page.]
 

 

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