We have installed smart thermostats that allow us to set upper temp of 72 degrees and monitor the heating patterns remotely. The building has 8 apts that are heated buy a single boiler. What would you do if several apts want to raise the top temp? --216.15.xx.xxx

That is not good way to reduce energy consumption. First install a Tekmar electronic boiler control system where there is a sensor on the indoor temperature, boiler heat loop temperature, outside temperature. With the combination of all sensors then boiler control limits the entire temperature of the entire heating system. In the rental units install non electric locking thermostatic control valves Danfoss or Honeywell Braukman where the temperature is set and locked where the tenants must have a special key to set temperature. Bimetal thermostatic boiler control valves increase temperature when windows are left open where the electronic boiler control sets up temperature within less then one degree where the tenant is forced to close window as the temperature drops in suite. Install pipe insulation on the hot water, heating pipes in boiler room puts more heat into the building where the boiler is warm already. There is a warm weather shut down on the electronic boiler which can be set to shut off heat when the outside temperature reaches the set temperature where in spring and fall the heating system shuts down on warmer days and nights. Installing a indirect hot water tank where the boiler is used to heat the immersion coil which is much more efficient then a direct fired tank as the standby loss is less the one degree per hour. Copper finned baseboards where cleaning fins with air compressor then installing reflective tape above the fins puts more heat into the room at a lower temperature. With a electronic boiler control where have in a indirect hot water tank function so in future when new hot water tank is required then install a indirect hot water tank. Usually a electronic boiler like a Tekmar is paid for in less then heating season. View some videos on You Tube about boiler controls and non electric thermostatic control valves. Most the apartment buildings the south side requires less heat during the day then the north side. --147.194.xxx.xx

I saved myself $35,000 in gas bills but had to spend around $30,000 for small tankless water heaters and direct vent wall heaters. Paid for themselves in 1 years... --47.155.xx.xxx

--72.231.xxx.xx

It would be expensive where installing a high efficiency wall mounted gas boiler in each rental which vents directly through the wall then each rental unit would have a separate gas meter where the tenants control and pay for natural gas consumption. So lot depends on how much capital one has to spend. With a wall mounted high efficiency gas boiler the existing radiators would be used where the heat would evenly distributed in the rental unit. Around 50,000 Btu would be more then enough for a rental unit. High efficiency gas boilers have a variable output where would rarely go up to maximum output. --147.194.xxx.xx

With this being a multi-family building - charging for extra heat is going to give mix input.......even from the folks that might be held responsible for their actions. --24.101.xxx.xx

Anyway, You might get an electrician to mount a few baseboard or in wall electric heaters for the times when the tenant feels its too cold for them,.then they can turn them on and have their own control. Note when I have done this in the past,..I find that they almost never turn them on (looking at their electric meter and usage) --66.30.xx.xxx

What would I do? I'd tell them to put on a sweater. 72 degrees is plenty warm enough. --76.178.xx.xx

--108.4.xxx.xxx

I installed 18000 BTU heat/cool units high on the walls . . . wired into their electric panel for 220. My heating and cooling costs per unit - zero. In rent controlled areas, which is the entire USA, that is a good number, since the Ts are often not paying rent til the moratoriums end. --174.65.x.xxx

72 degrees? I am turning on the AC at 72 degrees. What is WRONG with people? --50.82.xxx.xxx

Smiley face inserted here !! I have elderly relatives that have it set at 82 and also use a gas fire place in the evenings. Heat's been on since early October even though it's been VERY mild here so far. --72.70.xxx.xxx

The reason there is heating system is the heat loss in the walls, ceiling. If a building structure was super insulated then the heat loss would be zero where a heating or cooling system would not be required. There are net zero buildings which do not required a heating or cooling system where solar panels provide power then the building does not have to be connected to the grid. If unable to convert building to installing individual boilers then look at reducing the heat loss where starting off in the boiler room by insulating all the heating and hot water pipes with pipe insulation. When a new hot water tank is required replacing with indirect hot water tank will be expensive upfront but energy saving along with long life expectancy will pay off. Look at air sealing around doors and windows as air infiltration has a significant heat loss. If have multiple buildings then try one building then compare monthly natural gas consumption. If many of improvements are done DIY then the cost is going to be less. You Tube has many helpful videos on different renovation projects. Month by month energy improvements will pay off where have to get the money back then some. --147.194.xxx.xx