Do you find yourself looking at a cast iron radiator, unsure of what is what or where to begin? The best way is to become educated on the composition of the radiator as well as the reasoning behind it. What does each part do? Why cast iron, anyways? What is the purpose of painting or coating the radiator? Does size matter? There are many questions, so let’s see if we can’t find some answers.

Cast Iron - the Ideal Metal for Heating Your Home

The scientific reason why cast iron is used for radiators is that it has a high specific heat capacity. In everyday terms, this means that it takes a lot of energy to increase the temperature of the material. Why is this a good thing? Well, the harder it is to increase the temperature, the more energy the material stores per degree. So once you get it hot, there’s a huge amount of energy stored. This makes it easy to heat things that don’t require much energy to increase in temperature, like air. The specific heat capacity is also why cast iron is a common choice in other fields where it’s used to heat other things, like in cooking.

The Anatomy of the Radiator

A radiator is made of a few key parts. First you’ll see a few pipes that lead in to your unit. There’s typically only one or two. A valve will be attached to one of them. The radiator itself will have many sections and a few columns. The sections are the number of coils present, and the columns are how many repetitions of these sections go back. And that’s all there really is to a cast iron radiator, fundamentally.

radiator-labeled

Why So Many Coils and Tubes?

The trick to this one is knowing how radiators work in principle. Heat is coming off of the surface of the hot iron and flowing into your room. The transfer of heat to the air only occurs at the surface of the radiator. So manufacturer’s put in all sorts of coils and fins and loops in order to increase the surface area, thus making the heat flow from the radiator into the room much faster and more efficiently.

Radiator Size

The size of your radiator basically determines how much heat it generates. This relates back to the coils and tubes question. Basically larger radiator equals more surface which means faster heating.

The Purpose of Paint

Painting a radiator isn’t just about the asthetic of your room. It also plays a key role in determining heat output. Since the 1930’s, people have been painting their radiators in order to reduce the amount of heat it puts out. So if you’re radiator is too large, and your house is getting too hot, the cheapest solution is likely good ole fahsioned paint.

Fundamentals

That’s basically the entire fundamentals of cast iron radiators. Remember to be safe - if you’re unsure of how something works, it’s always better to ask questions than t potentially injure yourself.