Short answer: the type number of a panel radiator indicates the number of panels (first digit) and convectors (second digit). Type 11 has one panel and one convector, type 22 two panels and two convectors, type 33 three of each. The higher the type, the more heat at the same height and length, but the deeper the radiator. Type 22 is the most popular choice for living rooms.
All types at a glance
| Type | Panels | Convectors | Depth (approx.) | Suitable for |
|---|---|---|---|---|
| 10 | 1 | 0 | 4 to 5 cm | Hallway, toilet, where space is tight |
| 11 | 1 | 1 | 6 to 7 cm | Bedroom, small room |
| 20 | 2 | 0 | 7 to 8 cm | Sleek look, little heat |
| 21 | 2 | 1 | 7 to 8 cm | Kamer waar type 11 net te weinig is |
| 22 | 2 | 2 | 10 cm | Living room, kitchen, the standard choice |
| 33 | 3 | 3 | 15 to 16 cm | Large or cold room, heat pump |
The depth varies slightly by brand. A convector is the folded sheet between or behind the panels; it increases the surface area and therefore the heat output.
How much more heat does a higher type give?
At the same height and length, a type 22 gives roughly one and a half to two times as much heat as a type 11, and a type 33 about one and a half times as much as a type 22. The exact value is in the manufacturer's output table (at a flow temperature of 75 °C). At lower temperatures, such as with a heat pump, the output is lower.
Which type should I choose?
- Replacing an existing radiator: choose the same type and the same size, so the output is right and the pipes fit.
- Room does not get warm enough: one type higher in the same size (11 → 22, 22 → 33). Mind the depth.
- Switching to a heat pump: type 33 or a larger size, so there is enough heat at low temperatures.
View the Radson Compact radiators in type 11, 22 and 33.
Frequently asked questions
What does type 22 mean for a radiator?
Type 22 means two panels and two convectors. It is the most popular panel radiator for living rooms: plenty of heat at a depth of about 10 cm.
Is type 33 beter dan type 22?
Type 33 gives more heat at the same size, but is deeper (about 15 to 16 cm) and more expensive. It is the better choice if the room needs a lot of heat or if you use a heat pump.
Can I replace a type 11 with a type 22?
Yes, if there is room for the greater depth. The connection dimensions are usually the same for the same length and height, but always check the centre-to-centre distance of the connections.