I live in a apt. building built in the 60's. I am top right floor, boilers are bottom left. I have long low wall quot;registersquot; in each room. Are there actual pipes that run the hot water through these? They are metal, and bang when they expand from the heat, but since I don't have to pay for heat, I can live with that. How does the heat get out into my rooms - there is no blower. Also, I have a thermostat - could it possibly even be hooked up to anything, or is it just there to make me feel better? It is so hot in my apt sometimes that when the thermostat is on 60 I have to open my windows, and at other times my kitchen floor is so cold my eyes pop out when I step on it. Can anyone explain the mechanics of this to me?
The boiler heats the water as it go through usually a cast iron heat exchanger. The water circulates through the loop of pipes, giving off heat in the process. So naturally the apartments closest to the boiler will warm up faster than ones further away. So as the heated water travels through the radiator in your apartment, the radiated heat warms the rooms. The banging in the pipes may be air in the system and can be removed by bleeding it out. Many times the individual radiators have a small valve for doing just that. Chances are, the thermostat works but so does everyone else's. Unless you have individually controlled radiators, which I doubt, then when anyone in the building turns up the heat, then everyone gets it. So say another apartment wants to warm their place up but you don't, the boiler only knows there's demand and fires up. Since you're apartment is all part of the loop of pipes, you get tech heat right along with everyone else. You could always check for shutoff valves at each radiator to see if you can shut them off when needed.
Hot water circulates through the pipes. The pipes are made of a material that conducts heat well. Such pipes are usually also physically connected to a series of fins or plates that are also made of a material that conducts heat well. This is to give them more surface area through which to transfer the heat. The hot water heats the pipes (and the plates). The pipes (and plates), in turn give up their heat to the air. In the air a process called convection circulates the air throughout the room. Since hot air rises, it is not unusual for the floor to be cold and the air at head level to be comfortable. As for the thermostat, who knows? You'll have to ask the building superintendent about that one.
Actually, only some electric water heaters are instant as the first answer describes and they cost a small fortune including the need for some heavy duty wiring to their location. Convenient tho. Tank type water heaters are very similar in structure and gas is generally faster. Both have the problem of keeping the tank hot all the time, even when you aren't using water. Gas has a burner at the bottom which sends its exhaust up a baffled chimney up the middle of the water tank and the water takes its heat from that. Electric usually has a long narrow element coming in from the top and down into the tank. Both types have the cold replacement water put in at the bottom and the hot water taken out at the top to reduce the chance of your getting a blast of cold water in the hot.
