Double Panel Radiators

A double-panel radiator, also commonly known as a Type 22 or K2 radiator, is a heating appliance connected to a central heating system. As the name suggests, it has two steel panels to radiate heat with hot water flowing through both. Between these two panels, there are typically two sets of zigzagging metal strips called convector fins. This design significantly increases the radiator's surface area, which is key to its high heat output.

Double-panel radiators offer several key benefits, especially when it comes to heating larger or less-insulated spaces. Here's a breakdown of the advantages:

A double-panel radiator (Type 22) has two panels and two sets of zigzagging convector fins. This design dramatically increases the total surface area that comes into contact with the air. A larger surface area allows the radiator to transfer more heat into the room. It’s a core reason why they are so effective at heating a space.

Due to their increased surface area, double-panel radiators have a much higher heat output (measured in BTUs or British Thermal Units) than single-panel radiators of the same size. This means they can heat a large room or a room with significant heat loss (e.g. a conservatory or a room with large windows) more effectively and quickly than a single-panel radiator.

While they take a bit longer to heat up initially due to the larger volume of water, double-panel radiators are excellent at maintaining a comfortable temperature. Their high heat output means they can efficiently bring a room to the desired temperature, and then their mass helps to retain that heat, meaning your central heating system won't have to cycle on and off as frequently to keep the room warm. This can contribute to overall system efficiency, especially in larger homes.

Using a BTU (British Thermal Unit) calculator is the most effective way to choose the right size and type of radiator for your room, especially when considering a powerful option like a double-panel radiator. Here is a step-by-step guide on how to use a BTU calculator:

The most crucial part of the process is getting accurate measurements of the room you want to heat. You will need:

Many BTU calculators will then use these dimensions to calculate the cubic volume of the room.

To get a more precise BTU requirement, online calculators will ask for details about the room's construction and characteristics. These factors account for "heat loss," which is the rate at which heat escapes from a space. Common factors include:

After you input all the required data, the calculator will provide you with a single number. This is your BTU requirement—the amount of heat, in BTUs, that your radiator needs to produce to effectively heat that room to a comfortable temperature.

Once you have your required BTU figure, you can start shopping for double-panel radiators. All radiators should have their BTU output clearly listed in the product specifications.

Double-panel radiators (also known as Type 22) are generally more efficient at heating larger rooms. While they have a higher running cost than single-panel radiators, their ability to provide a greater and faster heat output means they can heat a larger space more effectively and quickly. This can actually make them more energy-efficient in the long run for a big room, as an undersized single-panel radiator would have to work harder and longer to achieve the same temperature, potentially costing more in the end.

Yes, a double-panel radiator will cost more to run than a single-panel model of the same size. This is because they have a greater volume of water to heat, requiring more energy. However, as mentioned above, if a room is large and needs a high heat output, a double-panel radiator may be more cost-effective overall because it can heat the space to a comfortable temperature more quickly and efficiently.

The extra set of fins in a Type 22 radiator gives it a greater surface area, resulting in an even higher heat output compared to a Type 21.

The cost of fitting a new radiator depends on several factors, but generally, fitting a double-panel radiator may have a slightly higher labor cost than a single-panel one. This is because they are heavier and the installation might be more complex, especially if the new radiator is a different size from the old one, requiring pipework adjustments. The cost of the radiator itself will also be higher.

Yes, you can typically replace a single-panel radiator with a double-panel one. However, there are a few important considerations:

A modern boiler is generally capable of running a double-panel radiator. However, it's a good idea to consult a professional heating engineer to ensure your boiler's capacity is sufficient for the total heat demand of your entire system. A larger radiator may increase the total volume of water in your system, which your boiler needs to be able to handle.

No, a double-panel radiator does not count as two separate radiators on your system. It is still a single appliance, albeit with a larger heat output due to its design.