I understand that if view–preserving automated shades are incorporated, that the project need not comply with the 500fc requirement. Can someone please help clarify for me the logic that for exemption from this threshold that the shades must be automated?
For energy calculations, I understand the logic behind the practice having solar shading automated for their effect to be included. A building user when thermally uncomfortable is likely to adjust the thermostat before the solar shading. However, I do not think that this is not the case for daylight/glare. A building user who is subject to glare is very likely to make adjustments to the curtains, drapes or blinds on an as needed basis. Whereas with, an automated system, the shades are often triggered regardless of whether or not a building user is subject to glare.
Do other group members agree with the above or is it do they feel that it is an advantage to have automated shades for glare?
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
May 9, 2014 - 5:59 am
The problem is that if you have a bad design with constant glare problems, the user will endup just leaving the shading in place with the lights on...even if the conditions improve and the shading is no longer required, he won't make the adjustment to open the shading because he does not experience discomfort in his current state. However, he is (perhaps subconciously) robbed of his views and no daylighting happens and the lights don't turn off. This defeats the intent of the credit.
TODD REED
Energy Program SpecialistPA DMVA
LEEDuser Expert
889 thumbs up
May 9, 2014 - 9:28 am
Not only what Jean said, but also with automated shades, they will come down at a certain level, so its assumed that the space will never reach an illuminance level that will be uncomfortable. Although, people are more acceptable to high daylight levels, including levels well over 500 fc. Without automated shades, it is not known whether someone would actually get up and pull the shades, therefore the daylight scenario must be designed to not exceed that level.
I have no problem with this option in LEED. The hardest element to design for in a building is the occupant. However, i believe that with proper occupant education, we don;t need all these automated controls. All to often we design these high tech automated controls and never tell the occupants anything. Then facilities is doing nothing but answering questions as to why this is doing this or that. One thing we neglect is to educate those who will use these spaces. I see way too much during an occupancy walk through of project where teachers have never been told anything about the lighting controls, thermostats, or why there are these "thingys" hanging from the outside of the buildings. To me it means failure and thats why you see sensors taped and all kinds of methods to override or disconnect those expensive control systems. I could go on about this topic but i believe there is word limit in posts.