Double Glazing Anti sun coating

statman

Hello, I am looking for a bit of advice please. We are about to order some large bi fold doors which will be at the back of the house which gets a lot of sun. We were looking at putting an anti sun coating to reduce damage to furniture. Has anyone got experience of this and if so can you tell me if the anti sun dramatically reduces the heat benefits and which colour looks good?

Thanks.

tim_n

UV rays is what damages furniture and I believe Low-E glass is supposed to reflect UV rays ("anti-sun"). I was under the impression that generally all Category A/B windows that are fitted now have Low-E as a requirement, so you may not need to pay extra.

The idea behind Low-E is to let the heat in during the winter and keep it out during the summer. Or so I've been told.

John_Pierpoint

Beware of getting confused about keeping infra red heat inside the building and keeping sunlight (including ultra violet) from getting into the building from the garden.

There are at least two manufacturers who will try to explain it to you and who might reply to your queries or at least point you at one of their customers. (The guardian web site explains how they produce different glass for different areas of USA from Alaska to Texas).

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Outside air

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XXXXXXXXX Plain glass - probably 4mm but will be toughened and perhaps thicker in a door.
~~~~~~~ Coating intended to stop too much solar radiation getting in

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Cavity probably something like 20mm and filled with exotic gas

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~~~~~~~~ Coating designed to reflect infra red heat back inside
XXXXXXXXX Plain glass as above.

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Inside air in Living room etc.

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Me, I've just got the infra red coating from Guardian (it is actually a purple colour when you break a unit and look sideways:eek:) and try not to put anything delicate in the sunshine and draw the curtains if we are not using a particular room in summer.

These coatings and extra glass thickness, do reduce the amount of light getting through the glass and thus take the "sparkle" off the outside view in winter.

You could train something deciduous over the top of the doors to give you more summer shading; like a grape vine.

http://www.guardian.com/
http://uk.saint-gobain-glass.com/b2c/default.asp?nav1=pr
http://www.pilkington.com/europe/uk+and+ireland/english/default.htm
http://www.youtube.com/watch?v=WpbOoQpwAFs
etc.

statman

Excellent, thanks for the replies. I will have a read through the links later.
Because the door is approx 4.5m it will be difficult to avoid putting things in harms way. I haven't even started the job of looking for some sort of pole to hang anything from for cover!

John_Pierpoint

Do it this year, as new regulations are coming that will require any changes to the envelope of an existing building to be "BETTER" (ie more energy saving) than those required for new build - you might find it become technically impossible to be permitted to install full length glass French doors (or prohibitively expensive).

statman

John_P Could i ask was it the climaguard residential that you used? Can't seem to find the infra red coating?
We will be having the doors hopefully within the month but thanks for that advice.
I think the guys we will be getting the doors from use Pilkington but i'm not even sure they understand which does what in that range!

thanks again

John_Pierpoint

This is the stuff I used three years ago:

http://guardian-europe.com/web/en/guardian_global/content/products/products-coated_glass-low_emissivity_glass-climaguard_d.html

I believe this is a rapidly changing market as the government keeps on jacking up the performance requirements to clearly uneconomic (in money terms) levels - but if our over populated planet is really going to hell in a hand basket because of climate change, I suppose any price is worth paying.

Back then I had the choice between Guardian & Pilkington - Pilkington used to be at the forefront of technology in the 1970's but has lost its advantages and sold out to the Japanese (in my humble opinion). Pilkington technology made your net curtains look as though the sun was turning them yellow (at that time).

The other thing you need to think about is "warm edge" technology - this is the strip that hold the glass appart (and in my cheap and cheerful units @ 23 quid per sq meter plus VAT this strip holds the deliquescent salts that extract any moisture trapped during the manufacturing process). It should stop you having a strip of condensation forming round the edge of the glass, there a metal strip would form a thermal bridge to make the inside glass cold.

http://www.eu.en.sunguardglass.com/IntroToAdvancedArchitecturalGlass/Post-TemperableSputter-CoatingTechnology/index.htm

http://en.wikipedia.org/wiki/Thin_film

http://www.impactglazing.co.uk/technical_info.php

k3v1n123

Hi i do this for a living everything these days have an energy rating.

It all depends on the size of the opening what type of doors are used will depend on the energy rating. This will then give you options as to which glass is used you should be looking at units which are argon filled and slightly tinted we use this on conservatory roofs as it keeps a lot of heat out otherwise it would be like an oven.