Single or Double Radiators, Which Should I Choose?
- Oct 4, 2022
- 4 min read
Updated: 2 days ago
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. Do you then decide to go for a Tube Radiator or a Convector?
Single convector radiators are commonly referred to as Type 11, while double convector radiators are called Type 22. If you want a full breakdown of the internal differences and the 'Type 21' middle-ground, see our Complete Guide to Type 11, 21, and 22 Radiators.
Not surprisingly, a single tube radiator has one panel or row of tubes, whereas a double tube 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 typically 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:
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 Single and Double Radiators
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.
Wall Strength
Double radiators are heavier - check that the wall (especially plasterboard or stud walls) can support the added weight.
Boiler Load
Adding multiple double radiators may increase your boiler’s workload. Make sure it can handle the additional demand.
System Balancing
After changing radiator types, your system may need rebalancing to ensure all radiators heat evenly.
Valves and Fittings
Valve positions might not line up with a new radiator’s inlets, especially if the dimensions differ. You may need angled or offset valves.
FAQs
Is a double radiator more efficient than a single?
A double radiator is not necessarily more 'efficient' in terms of energy use, but it is more 'powerful' because it has a larger surface area. While it uses more water and takes slightly longer to heat up, it produces significantly more heat (BTUs) than a single radiator of the same dimensions, making it the more effective choice for large or poorly insulated rooms.
Can I put a double radiator on a single radiator's pipes?
Yes, you can usually install a double radiator on existing pipework, provided the width (length) of the new radiator is the same. However, because a double radiator is deeper, the pipes may need to be adjusted or "offset" to reach the valves, which are now further away from the wall.
Do double radiators cost more to run?
Double radiators do not significantly increase your energy bills, but they do increase the 'load' on your boiler because they hold a larger volume of water. Your boiler will work slightly harder to heat the initial volume of water, but once the room reaches the target temperature, the double radiator will maintain that heat more effectively than a single-panel model.
