HVAC equipment

Probably the worst place of employment that I have ever worked at was cleaning hotel rooms. The hotel all of us have in our small town in very just a run down motel complete with actual metal keys & tube TVs. It has been the same since it was set up a few years ago. It also has an attached bar to it, which is the only bar in town. The hotel will get a lot of gross & disgusting looking people… Cleaning out the rooms they stayed in was not great. What very was bad was that there were smoking & non smoking rooms… Do other places still do that? Basically they all smell of cigarettes. I am wondering if it is the central air conditioning system or the smoke going through the walls. The smoke contaminates every hotel room. I remember while I still was there the owner tried to get rid of the cigarette smell. He installed air cleaners in the rooms that did not allow smoking. About 1 day the rooms smelled nice, but the air cleaners could not stop the stench. I suppose it is that central air conditioning system uses HVAC ducts to cool the weird rooms. The air ducts would move the smelly air into all the rooms. So it did not matter who was smoking & who was not. The smell simply moved from 1 location to the other. The cooling idea should have been changed into a ductless mini split air conditioner for each room. Every room would have their own air handler & thermostat to do the job in. That way the temperature & smell are contained in the single room. heater