Forced Hot Water Heating System Theory

There are three different types of heat; convection, conduction and radiant. When you utilize forced water heating you actually use two of these three types. Those would be conduction and radiation. There are primarily three types of water heating systems as well. Of these three, forced water heating is the most common.

• All three (gravity flow, baseboard convection and pumped) of the hot water heating systems relies on a boiler to make the water hot. After heating the water it is then moved through the building taking the heat with it for delivery. The most common fuels used to heat the water are gas and coal. The burning fuel heats a coil in most cases and the coil heats the water.


• The way it works is that in pumped water systems two methods are used circulate the water. One is where the water is constantly pumped and the heat is delivered through pipes and radiators and the other is the convection baseboard type. The water is delivered the same as before but the heat is distributed by way of fans blowing over thin metal directional plates.


• The other system of delivery is the gravity system. In this case the boiler heats the water and as it heats it displaces cold water and pushes it through return pipes to the boiler to be heated again.


• There are certain systems in where a thermostat controlled circulator will be used. The water is kept at a predetermined temperature by what is known as an aquastat that does in water what a thermostat does in air. However you can still control the boiler with a normal thermostat. You simply set your desired temperature as you do normally and when the kick in point is reached the thermostat kicks on the boiler and runs the heating cycle again.