[Radiance-general] Daylighting metric for outdoor spaces

Thu Dec 8 13:26:35 PST 2011

I found the presentations from Solar Energy at Urban Scale Workshop really
helpful to me in the related subject:
http://www.utc.fr/seus/iso_album/abstract_seus.pdf

You can find John's presentation here as well
Regards,
Mostapha

On Thu, Dec 1, 2011 at 10:34 PM, Mostapha Sadeghipour <sadeghipour at gmail.com
> wrote:

> Hi Michael,
>
> Thank you for both emails today. I knew that statement is flawed, and I
> think I mentioned that before. Nevertheless thank you for the links.
>
> I think the best way, to find the answer, is to run series of annual
> simulations for different locations. Will do soon.
>
> Mostapha
>
>
> On Thu, Dec 1, 2011 at 10:19 PM, Michael Donn <Michael.Donn at vuw.ac.nz>wrote:
>
>> Hi Mostapha
>>
>> I asked my colleague Christina MacKay (Christina.MacKay at vuw.ac.nz) for
>> references / inks to her papers defining 'warm shade', and received this
>> list:
>>
>> Please refer to the following key papers -
>>
>> Mackay, C. (2009). Environmental Shade for Protection from UVR: A Design
>> & Teaching Resource. Proceedings of the 26th Conference on Passive and Low
>> Energy Architecture (PLEA). 22-24 June 2009. (pp 314-319). Quebec City,
>> Canada.
>> Mackay, C. (2006). Towards a safe sun-bathing canopy. The 23rd Conference
>> on Passive and Low Energy Architecture. (pp. 581-586). Geneva, Switzerland.
>> Mackay, C A. (2005, April). Living outside in the sun - a historical
>> review of New Zealand outdoor living spaces. Inside-outside symposium,
>> IDEA, RMIT. Melbourne, Australia.
>> Gies, P., & Mackay, C A. (2004). Measurements of solar UVR protection
>> provided by shade structures in New Zealand primary schools. Photochemistry
>> and Photobiology, 80. (pp. 334-339). http:
>> www3.interscience.wiley.com/cgi-bin/fulltext/11921593/htmlstart.
>> Mackay, C A. (2003). Designing safe and comfortable indoor living spaces.
>> Passive Low Energy Architecture, Proceedings of 20th International
>> Conference, November 2003. Ins by Bustamante, W. & Collados, E. (Eds).
>> Pontificia Universidad Catolica de Chile. B-24. (pp. 321-325). Santiago,
>> Chile.
>> Mackay, C A. (2003). Sunshade Design in New Zealand Primary Schools.
>> Passive Low Energy Architecture - Proceedings of 20th International
>> Conference, November 2003. Ins by Bustamante, W. & Collados, E. (Eds).
>> Pontificia Universidad Catolica de Chile. A-18. (pp. 143-150). Santiago,
>> Chile.
>>
>> Cheers
>> Christina
>>
>>
>>
>> ------------------------------------
>> Victoria University of Wellington School of Architecture
>> Michael Donn
>> michael.donn at vuw.ac.nz
>> PO Box 600
>> 139 Vivian St
>> Wellington
>> New Zealand
>> tel: +64 4 463 6221
>> fax: +64 4 463 6204
>> mobile: +64 21 611 280
>> Skype ID:the_donn
>> ------------------------------------
>>
>> -----Original Message-----
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>> To: radiance-general at radiance-online.org
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>> Today's Topics:
>>
>>   1. Re: Daylighting metric for outdoor spaces (Mostapha Sadeghipour)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 30 Nov 2011 19:27:27 -0600
>> From: Mostapha Sadeghipour <sadeghipour at gmail.com>
>> To: Radiance general discussion <radiance-general at radiance-online.org>
>> Subject: Re: [Radiance-general] Daylighting metric for outdoor spaces
>> Message-ID:
>>        <CAAd_PgQhKsZ03xVk9ET+vJ3QFzCFn1JWE4=
>> 1uK+hD4LC6hxYLQ at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> Hi Andy,
>>
>> Thank you for clarification and explanation. It was so informative.
>>
>> I agree that using hours of sunshine (sunlight hours) in this way totally
>> make sense however in the code I mentioned it was a metric for building
>> envelopes (e.g. two hours of sunlight hours in 21st December is needed for
>> residential buildings).
>>
>> As you said the weakness of metrics like VSC or Daylight Factor
>> (SC+ERC+IRC) is not being climate-based and orientation sensitive but
>> maybe
>> this is the best possible way for now.
>>
>> Thanks,
>> Mostapha
>>
>>
>> On Wed, Nov 30, 2011 at 12:18 PM, Andy McNeil <amcneil at lbl.gov> wrote:
>>
>> > Hi Mostapha,
>> >
>> > BRE has a metric - Vertical Skylight Component - for what you describe.
>> >  It is intended as a planning tool to insure that housing blocks are not
>> > located to close together.  It is also used in rights to light
>> litigation
>> > in the UK.  It's independent of climate though, it's mainly to ensure
>> that
>> > an appropriate percentage of daylight is made available at the window
>> (i.e.
>> > not too many tall buildings nearby).  I'm not saying it's a great
>> metric,
>> > but it's commonly used for what you want to do.
>> >
>> > VSC is commonly coupled with the hours of sunshine in a courtyard metric
>> > you mentioned in an earlier email.  I just want to point out that this
>> is
>> > not a daylight metric but a planning tool to ensure that courtyards are
>> not
>> > more damp and dank than an open park in the same climate.  For example,
>> if
>> > you have a week of damp overcast weather both your open space and your
>> > courtyard will be damp, but then when you have a day of sunshine your
>> park
>> > will dry up, but your courtyard may not if there isn't sufficient sun
>> > penetration.  A courtyard that stays damp gets even worse in the next
>> week
>> > of wet weather.  The metric is intended to prevent mold, mildew and
>> > perpetually damp courtyards.  So in reality this metric is more
>> applicable
>> > to climates like London and Seattle than Phoenix or Dubai.
>> >
>> > Andy
>> >
>> >
>> >
>> > On Nov 30, 2011, at 9:31 AM, Mostapha Sadeghipour wrote:
>> >
>> > Hi John, Michael, et al.
>> >
>> > Michael,
>> >
>> > Sorry if it wasn't clear enough. I think you get the concept. Yes! I
>> > wonder if there is a number to determine the outdoor illuminance to
>> provide
>> > enough illuminance level inside. What you are saying is true and the
>> > effective parameters are much more than only VLT and ceiling reflectance
>> > but if I want to consider all of them I should modify the geometry and
>> run
>> > the lighting simulation.
>> >
>> > The way I did the ray-tracing in my mind was the simplest possible
>> > backward ray-tracing. I started from the sensor inside, then traced only
>> > one ray upward and bounced it from the ceiling to the glazing. So
>> > illuminance level inside the space is equal to illuminance level outside
>> > the glazing (on the envelope of the building that I can simulate)
>> multiply
>> > by VLT of the glazing multiply by the reflectance of the ceiling. In
>> this
>> > way I can make a target for the illuminance level on the envelopes
>> rather
>> > than indoor.
>> >
>> > The question could be more general though and thinking about the
>> relation
>> > between outdoor illuminance level and then the external envelopes.
>> >
>> > John,
>> >
>> > Thank you for the great link! This is exactly what I'm talking about. I
>> > actually ran the accumulative annual study. That's true that cumulative
>> > result shows you get less illuminace in more dense areas but what are
>> the
>> > cutting levels? Do we have the concept of over-daylit for outdoors?
>> >
>> > For example if I calculate the availability of useful daylight
>> illuminance
>> > based on 100 lux and 2500 lux for working hours and calculate the result
>> > based on the percentage of hours a large portion of the well-daylit
>> outdoor
>> > spaces will be considered as over-daylit because they receive more than
>> > 2500 lux, and then the more dark outdoor spaces located in Seattle or
>> > London (hi Rob!) will be assumed as well-daylit since they will be in
>> the
>> > range. We already knew this is not true and the spaces next to an
>> outdoor
>> > space with 150 lux horizontal illuminance level cannot be well-daylit.
>> >
>> > Maybe we can say there should be no upper-limit for outdoor illuminace
>> > level since we can always mitigate the light level by building envelope
>> > design, but what is the lower limit then?
>> >
>> > Best,
>> > Mostapha
>> >
>> > PS.1: I liked the concept of "warm shade" so much. So interesting to
>> think
>> > about.... Can you send me a link to the paper or any other resources?
>> >
>> >
>> > On Wed, Nov 30, 2011 at 10:26 AM, John Mardaljevic <jm at dmu.ac.uk>
>> wrote:
>> >
>> >> Hi Mostapha,
>> >>
>> >> > For an urban design study I wanted to avoid measuring light levels
>> >> inside the buildings as far as possible.
>> >>
>> >> How about using cumulative values, say annual or maybe monthly?  You
>> >> could also look at just the hours of occupancy.  Some examples here:
>> >>
>> >> http://www.iesd.dmu.ac.uk/~jm/doku.php?id=academic:urban-solar
>> >>
>> >> The image for London clearly shows the effect of tall buildings
>> reducing
>> >> the ground level cumulative illuminance (actually, irradiance in the
>> legend
>> >> but just x 100 to estimate klux-hrs / yr).
>> >>
>> >> Best
>> >> John
>> >>
>> >> Reader in Daylight Modelling
>> >> Institute of Energy and Sustainable Development
>> >> De Montfort University, The Gateway, Leicester, LE1 9BH, UK
>> >> Tel: +44 (0) 116 257 7972
>> >>
>> >> jm at dmu.ac.uk
>> >> http://www.iesd.dmu.ac.uk/~jm
>> >> http://dmu.academia.edu/JohnMardaljevic
>> >>
>> >>
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