Shabbat

Question

In a hotel I saw that the The heating / cooling system had a note to the effect that the system would take 15 minutes to get back to your desired temperature because as an energy saving measure, it slowed down when you were out of the suite and only came back up to speed when you returned. (Clearly a smart energy savings idea considering that many hotel rooms are empty all day as occupants are attending to business.) Looking around I saw that there were multiple sensors in the rooms - akin to those you may see with a burgler alarm system. I don't know if they were motion or temperature or both - I suspect motion. Is this a problem on Shabbat?