Disadvantages of Daylighting

Although the various benefits that daylighting has to offer the side effects of using natural lighting as the key source of light in a space has also its disadvantages that are crucial to take into consideration when strategically applying a daylight design to a space.

If natural light is used excessively may it be from one side of the space or exaggerated overall the intensity of the light may cause glare discomfort. This occurs when a significant amount of light enters a space and a large difference is at play between the task being observed and the area that is lit with the entering light. If the occupant is exposed to excessive light for a short period of time the glare type at hand would be discomfort glare which means that the occupant would be exposed to direct light at a close range that the eye can handle for a short period of time. Indirect glare results from light being reflected off surfaces and causing discomfort to the eye off a surface. If the occupant is exposed for a long period of time disability glare would be developed resulting in the occupant to have vision impairment.   

diagram discomfort glare

diagram indirect glare

Another vital disadvantage that daylight causes is the thermal effect in the space itself. To have daylight accessing a space the entrance point is through transparent materials; glass. Due to the fact that the sun is a powerful natural source of heat and light to control the intensity of both aspects is not optional; therefore it is vital to be able to soften the intensity with the use of diffusers as if not the excessive amounts of heat and light would cause discomfort to the occupant and may be hazardous to one’s health.

To be able to lessen the disadvantages to the minimum it is vital to have light diffusers next to windows such as light shelves that would be placed underneath the window causing the sun to first hit the shelf and then reflect in the space with lower intensity. Another optional diffuser is through the use of materials in front of the windows such as light curtains that are able to soften the light and the heat yet still accessing the space.

diagram light shelves

Light shelves

curtians 

lourves 

It is vital as designers to carefully calculate the amount of daylighting that would be accessing the space to be balanced due to the consequences that may result in the future.  

Reference Links;  

What are the Advantages and Disadvantages of Daylighting?. 2013. [ONLINE] Available at:http://www.lightingandmaintenancesolutions.com/blog/business/advantages-disadvantages-daylighting/. [Accessed 04 April 2015]. 

 FacilitesNet Stuff 17.02.2009 Daylighting Advantages And Disadvantages - Lighting Coverage . 2015. [ONLINE] Available at: http://www.facilitiesnet.com/lighting/topic/Daylighting-Advantages-And-Disadvantages--19593. [Accessed 04 April 2015]. 

Windows for High-performance Commercial Buildings.  2013 - 2015. [ONLINE] Available at:http://www.commercialwindows.org/glare.php. [Accessed 04 April 2015].

A. Williams 04.09 NBS | National Building Specification | Building services: Dealing with glare: improving visual comfort. [ONLINE] Available at:http://www.thenbs.com/topics/BuildingServices/articles/glare.asp. [Accessed 09 April 2015].