The most common form of central heating radiator in modern houses is the compact or convector radiator. These come in three main types which we will endeavor to explain in this article.
You certainly don’t need to be a plumber to understand how these types differ and it should help to make sure you are specifying the right ones for your needs.
Convector radiators are made from “panels” and “fins”. Hot water enters the radiator and traverses through the panel which in turn heats up the fins and the air around them. This heat rises and heats the room up. Below is a top down view of a Type 11 radiator which shows a single panel and a single set of fins.
The three main types of radiators are Type 11, Type 21 and Type 22.
The numbers refer to the number of panels and the number of fins on each radiator, so a Type 11 has one panel and one set of fins, a type 21 has two panels and one set of fins and a type 22 has two panels and two sets of fins.
Top down diagrams of each type can be seen below :-
Type 11
This is the slimmest of the three types, it has a single panel and a single set of fins, consequently it has the lowest heat output. These are especially useful in small rooms where a high heat output is not required, utility spaces, cloakrooms etc. They are extremely useful when space is at a premium as they have the minimal amount of projection into the room.
Type 21
These are a very similar design to the Type 11 but they have an additional panel at the back for an increased heat output, for exact outputs you can refer to the BTU’s listed on each product. Often used in medium size rooms, bedrooms etc where a higher heat output is required than a Type 11 and more room is available for the increased projection / width.
Type 22
The highest output of all the types of convector radiator, these are reserved for the largest rooms where the need for output outweighs the larger depth and projection. Boasting 2 panels, surrounding two sets of fins the amount of heat that be generated is greatly increased.