In order to understand hydronics systems all you need to do is study the second law of Thermodynamics. While you’re at it, ask what convection, conduction and radiation have to do with it.

It may sound complicated but it all ‘boils’ down to heat dispersion. That is, heat doesn’t stay in one place all the time. It moves from one location to another.

You take part in this movement when you cook. The heat travels from the stove to the pan into the food. It might travel into your fingers if you are not careful.

So, what’s hydronic about that? Nothing really, but the same principle applies.

Hydronics systems transfer heat or cooling through water that is enclosed in tubing commonly known as pipes.

“What is hydronic heating?”

Water is sent into pipes from a boiler. The heated water travels into baseboards or radiators. The heated water now starts to cool down as it travels. Next, the cooler water circulates back into the boiler system. This is called a closed system of pipes.

So, what were those three science words again? Lets look at the definitions we all learned in fourth grade but forgot:

1. Convection is the action of warmer fluids or gasses rising and colder fluids or gasses sinking. Wind currents are a form of convection.
2. Conduction is the transfer of heat through matter that is not affected by the heat flow. The matter doesn’t change its basic structure or shape. Some materials are better conductors than others are.
3. Radiation is the process of emitting thermal or electromagnetic energy through empty space. When the energy meets an object, it will transfer the heat into the object. Radiation does not require a material in order to move from one place to another. Sunlight is an example of radiant energy.

In a hydronics system, the hot water moves from the boiler into the pipes. The water moves through the metal pipes, the fins of the baseboard are heated through conduction. Metal is a good conductor. A baseboard is made up of many tiny fins laid out close together. When these fins heat up, they release heat into the air through radiation.

Another type of application of the same principles is radiant floor heating. The piping or tubing is flexible and lies up close to the underside of the floor or else lay in concrete slabs underneath the floor. The tubing transfers the heat to the floor so that the heat can be emitted through radiation.

Boilers are the heart of the hydronics system and can be made of either cast iron or steel. They are fueled by home heating oil.

Cast iron boilers come in two types:

1. Wet base – where the water in the heat exchanger surrounds the combustion chamber.

2. Dry Base – where the water filled heat exchanger is set on a base above the combustion chamber.

Steel boilers are also of two types:

1. Fire tube – combustion gasses flow through the tubes and water circulates around them.
2. Water tube – water passes through the tubes and gasses circulate around them.

This information was extracted from The Complete Guide To Residential Oil Heating.