How a Radiator Works - A Comprehensive Guide

Updated: September 26, 2023

Have you ever wondered, how does a radiator work? This common household item is a crucial part of many homes, providing warmth and comfort during the colder months. But how does it manage to heat up your home so efficiently? Let's delve into the fascinating world of radiators and learn how they work.

Understanding the Basics

A radiator is a type of heat exchanger designed to transfer thermal energy from one medium to another for the purpose of heating a space. In a typical home heating system, the radiator is connected to a central boiler that heats water. This hot water then circulates through your home, and through your radiators, transferring its heat to the metal of the pipework and radiators, and then to the air in the room.

The Role of Convection

While the term "radiator" might suggest that these devices primarily radiate heat, the truth is that they primarily work by being a cog in a process called convection. As the hot water heats the radiator, the air around the radiator also heats up. This hot air rises, and cooler air rushes in to replace it, creating a cycle of warm air circulating throughout the room. This process is incredibly efficient and is the primary way that radiators heat your home.

The Role of Radiator Valves

If you haven't already noticed, you need to know that your radiator has two valves. One of these is the flow valve, which controls the amount of hot water entering the radiator. The other is the return valve, which allows the cooled water to return to the boiler to be reheated. By adjusting these valves, you can control the amount of heat your radiator produces.

Typically the return valve will be left fully open. The flow valve can then be adjusted to allow you to adjust the temperature of your room. Better still, you could invest in some thermostatic radiator valves which will maintain a comfortable temperature in your room on your behalf.

We talk about Radiator Valves in more detail in our blog post: How Radiator Valves Work.

Different Types of Radiators

There are several different types of radiators, each with its own advantages. For example, cast iron radiators are highly durable and retain heat well, making them an excellent choice for older homes. On the other hand, modern radiators are often made from lighter materials like aluminium or steel and come in a variety of stylish designs.

Radiators also come in different orientations; horizontal and vertical radiators. If you're wondering which radiator you need, then this is wholly dependent on the space available and the BTU required for your space. We discuss all of this in our blog post: What Radiator Do I Need? 

Here at PlumbHQ, we also stock a wide range of different coloured radiators including black radiators, white radiators and chrome radiators.

Frequently Asked Questions

A radiator works by heating the air around it. This hot air then rises and is replaced by colder air. This cycle continues and creates a convection current, which keeps your entire room warm.

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