re: UV
OK, uncoated window glass blocks about 90% of energy below 300nm rule of thumb IIRC, amounting to small-single-figure percentage of total energy in 'daylight'. It matters in front of artwork and fine finishes, but not in terms of thermal issues.
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nothing to do with sun's heat, many still remembered wobbling millennium bridge here
yep, in London, for me, a design engineer myself, yet another example where "art" beats old school good engineering practices, especially with young CAD savvy designers. My 70yrs old architect uncle did better when come to his judgments even he still draws manually 🙂.
quite embarrassing with today's available computer aided simulation tools, do we still teach failure mode effect analysis in college?
yep, in London, for me, a design engineer myself, yet another example where "art" beats old school good engineering practices, especially with young CAD savvy designers. My 70yrs old architect uncle did better when come to his judgments even he still draws manually 🙂.
quite embarrassing with today's available computer aided simulation tools, do we still teach failure mode effect analysis in college?
Actually Arups the engineers had to pay for that fix to the bridge - as much a PR failure as a design issue per se.
ha ha, still hard to imagine, have worked with Arup's engineers back in my automotive R&D days, they're very capable people, should be Arup's decision maker today
IIRC the same issue occured at the Vdara in Vegas, where sun is surely not unexpected.
Aparently the focal point tends to wander around the pool area, and can produce sufficient power density to burn hair.
I would LOVE architects to also be required to specialise in types of building and to actually go and work (In the building operations crew) in whatever type of building they wish to specialise in for a year.
It would result in things like venues having sufficient toilets (The interval rush is short and very busy, a nice gotcha is when the header tank cannot refill fast enough), office blocks with lifts sized for the 5:30 rush, railway stations with announcment systems that actually work, and factories with turning space for trucks (All screwups I have seen and that having an adult on the design team may have spotted).
Regards, Dan.
Aparently the focal point tends to wander around the pool area, and can produce sufficient power density to burn hair.
I would LOVE architects to also be required to specialise in types of building and to actually go and work (In the building operations crew) in whatever type of building they wish to specialise in for a year.
It would result in things like venues having sufficient toilets (The interval rush is short and very busy, a nice gotcha is when the header tank cannot refill fast enough), office blocks with lifts sized for the 5:30 rush, railway stations with announcment systems that actually work, and factories with turning space for trucks (All screwups I have seen and that having an adult on the design team may have spotted).
Regards, Dan.
UVC is blocked by the ozone layer. It never reaches earth. Glass blocks UVB and UVA passes through.
Polycarbonate blocks 100% UV.
I still haven't received a reply to my question: does window glass reflect or absorb UV? Several people have said that it stops/passes some UV. Different question. So what happens to the UVA and UVB which does not pass through the glass - is it reflected or absorbed? My guess is that much of it is reflected, but that would depend on the refractive index of glass at UV.
The point of my question was whether people in the focus will get sunburnt as well as heated.
The point of my question was whether people in the focus will get sunburnt as well as heated.
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Window glass is an interference filter. It interferes with the transmission.
Other glass used for uv such as mug2 and mug6 are absorption filters. Glass such as this can br used along with clear glass as sort of a bandpass for uv to narrow the transmission to specific wavelengths in certain applications. (Not window glass, mug2 and mug6 is dark blue and purple in color)
Window glass blocks uvb which is the part of the spectrum that causes burning. It is the part that stimulates melanin in the skin. UVA is the part that browns the melanin and creates a tan. Both are required for tanning. UVC is germicidal and is not naturally occurring as it is blocked by the ozone layer. UVB also stimulates vitamin D production in the body.
Other glass used for uv such as mug2 and mug6 are absorption filters. Glass such as this can br used along with clear glass as sort of a bandpass for uv to narrow the transmission to specific wavelengths in certain applications. (Not window glass, mug2 and mug6 is dark blue and purple in color)
Window glass blocks uvb which is the part of the spectrum that causes burning. It is the part that stimulates melanin in the skin. UVA is the part that browns the melanin and creates a tan. Both are required for tanning. UVC is germicidal and is not naturally occurring as it is blocked by the ozone layer. UVB also stimulates vitamin D production in the body.
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I pet peeve is Australian trained architects designing flat roofed buildings here in Malaysia. We get so much heavy rain they ALL leak.
That, of course, was my joke. I lived in London - it's not a place I think of as sunny. Thus the rather rare risk. 😛
You are not alone. Legend has it that the roofs at Versailles leaked for years when it was first built. The palace has been built in the "Italian Style" with roofs suited to the dry parts of Italy, not the soggy climate to the south of Paris.
implementation is..
be careful when you meet designer that do not speak the word 'elements' 🙂
1/2" deep rain water on top of large flat roof can surprise us
be careful when you meet designer that do not speak the word 'elements' 🙂
1/2" deep rain water on top of large flat roof can surprise us
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