Hi folks, I recently got a job on a Hotel, it has 5 floors: level -1 underground, we have the water tanks and the restaurant level 0 street level, we have only 3 rooms there level 1 first floor, we have 4 rooms level 2 second floor, we have 8 rooms level 3 third floor, we have a special room for the Spa Above this level we have the roof with the gas tank and the heaters. We have been working there a month and we have arrived to a conclusion: that Hotel is a disaster, from the energetic point of view. The big problem is how the building is designed to heat the water which means the gas bill is extremely expensive. I will try to show it with an image. (Attach Files) Basically the heaters work with gas, and they are on the roof of the building. I am not sure about that but I think that it is for safety reasons. Well, the problem is that the water tanks are on the lowest floor, undergrownd, they can't be more far away from the heaters. There are 16 rooms in that hotel and the best ones (8) are on the third floor, very close to the heaters... but far away from the water tanks. It is impossible to do it worse since the hot water needs to travel the longest possible distance, which is like twice the height of the building, I guess there is a massive loss of energy in that travel which means the heaters must work a lot and the pumps too. What ideas would you suggest to improve the efficiency of that system? I have two ideas but I don't know if they are possible, or even if they could work: 1.- Change the water tanks to the level 3 which means they would be very close to the heaters and the hot water only should travel once the height of the building, since we have 8 rooms on the second floor we would host our customers on those rooms as much as we could. The doubt is if it is possible to put 1500 kg of extra weight on a floor, which is the weight of those water tanks. Maybe it is not possible. 2.- Using sensors to start-stop the system only when necessary. I have no idea about how exactly implement that. Any other idea? What do you think about the system? Is that something common on Hotels or is it just the engineer in this one missed the efficiency classes? Thanks!