There is no doubt that significant direct energy savings are achieved using smart lighting solutions with intelligent light fixtures. However, there are also indirect energy savings. For example dimmed lights will generate less heat reducing cooling loads on HVAC plant. So are there any studies that have evidenced such and what are the indicative numbers?
I recently asked this question on one of my LinkedIN threads and here are the best of the replies:
Indirect heating and cooling load impact, here are some links that might help …
http://www.csemag.com/single-article/integration-lighting-and-hvac-systems/6cdbfda10abe16e4770416fd60235987.html p23 and following of http://isites.harvard.edu/fs/docs/icb.topic1136043.files/07%20ASHRAE%20Standard%2090.1-2010.pdf
This link takes you to an on-line calculator, which claims to determine anticipated heating load from a given lighting deployment, http://liacs.omslighting.com/
Additional comments were as follows:
Unless a software is used (like is nowadays mandatory in many parts of the world) to do a real calculation a rule of thumb is to count with 5% extra savings due to reduction of needed HVAC when using controls relative to not using controls (in new construction, usually the lighting upgrade itself will cut away the biggest heat load by using more efficient sources and fixtures in renovations).
It is also suggested that the heat introduced into your space by lighting is the plug power times the usage time(if undimmed) = conservation of energy, even the light emitted will be converted to heat eventually !!! Unless of course you have ventilation and especially if you have air extraction over the luminaires … a good luminaire supplier will be able to give you data on their luminaires about noise, pressure drop and heat load reduction as a function of air flow …