Single or Double Radiators, Which Should I Choose?

Radiators Direct
Oct 4, 2022
3 min read

Updated: Jul 29

White tube radiator fixed to a grey wall — Pictured: Vettori Double Vertical Radiator (Click the image to view)

When choosing radiators for your home, it can be challenging to know exactly what size and type of radiator you need. Choosing whether you want a single or double radiator is another consideration to make - each has its benefits.

Not surprisingly, a single radiator has one panel or row of tubes, whereas a double radiator has two panels or two rows of tubes. You can see this by looking at the radiator side-on.

When weighing the options, the main things to consider are heat output, size, and, of course, cost.

Single Radiators

Single radiators consist of one panel and one convector (set of fins) or one row of tubes. With less surface area, a single radiator emits less heat than a double. The main benefit is that single radiators tend to be slimmer, and so for areas such as hallways or downstairs toilets, where space is tight or limited, they are a good option. They are also likely to be the more cost-effective option for smaller rooms that don’t need a large heat output, such as a bathroom or en-suite. Single-panel convector radiators are sometimes known as Type 11 Radiators.

Check out our Type 11 Radiators:

Double Radiators

Double Radiators, rather unsurprisingly, emit more heat than their single-panel counterparts, by way of a 2nd heating panel or row of tubes incorporated into their design.

The convector variants are typically known as Type 22 Radiators - 2 panels and 2 convectors (sets of fins), thus increasing their surface area when compared to Type 21 Radiators.

This means that in theory, you could replace your single radiator with a smaller double radiator and still achieve the same heat output (level of BTUs), but take up less wall space. Another benefit is that where you may initially have had two single radiators, you can meet the same output requirements with just one double radiator. This will again take up less wall space and be one less radiator to heat and push water through.

Check out our Type 22 Radiators:

There are also Type 21 Radiators available, which consist of 2 panels and 1 layer of fins as per the diagram below:

A top-down diagram of a type 21 convector radiator.

Have a look at our Rossetti Type 21 Convector Radiator.

Can I Swap a Single Radiator for a Double (And Vice Versa)?

Yes, you can swap a single radiator for a double or the other way around, as long as the wall space and pipework allow for it. Double radiators offer more heat output, ideal for larger rooms, while singles suit smaller spaces. You may need to adjust brackets or pipe positions, so it’s best to check dimensions carefully or get professional advice before making the switch.

Other Considerations When Swapping

🔧 1. Heat Output (BTU Requirements)

A double radiator emits more heat. Make sure it's not too much for the room, as overheating can be inefficient and uncomfortable.
If going from double to single, ensure the new radiator still meets the room's BTU requirement.