Hello Gaetano, in the IEEE there are some information and you can find something in the attached file (page 80).

Best Regard

Marcio

Many Thaks. I appreciate your contribution!

Best Regards

Gaetano

see also

http://w3.siemens.com/market-specific/global/en/data-centers/documents/bau-impact-on-energy-efficiency.pdf

I can safely that any such systems require people well experienced in order to achieve sustainable savings. The systems themselves, are well just systems!

Most hotels largest energy consumers are HVAC, cooking and hot water.

You are absolutely right! Smart systems work only when people are smart too! Many thanks for your help.

Sincerely

Also see

http://hes.unwto.org/sites/all/files/docpdf/analysisonenergyusebyeuropeanhotelsonlinesurveyanddeskresearch2382011-1.pdf

http://hotelnewsnow.com/Articles/25821/How-to-reduce-energy-consumption-in-hotels

https://bizenergyadvisor.com/hotels-and-motels

http://www.greenthehotels.com/eng/BohdanowiczChurieKallhaugeMartinacHawaii2001.pdf

or Google

energy consumption of hotels