Steel panel radiators are widely used in residential and commercial hydronic heating systems because they combine reliable heat output, compact construction and straightforward installation. For distributors and project buyers, however, choosing the correct type code is essential. The two digits describe the number of water-carrying panels and convector fin sections inside the radiator.
What the type numbers mean
Type 10 has one panel and no convector fins. It is slim, easy to clean and suitable for locations where hygiene or minimum projection from the wall matters. Type 11 adds one convector section behind the panel, increasing output without greatly increasing depth.
Type 21 uses two panels and one convector section. It offers a practical balance of output, depth and cost. Type 22 has two panels and two convector sections and is one of the most frequently specified formats for modern homes. Type 33 combines three panels with three convector sections, delivering high output where wall space is limited.
How buyers should compare models
Do not compare radiators by dimensions alone. Request certified heat-output data at the same temperature conditions, normally shown as ΔT50 and, where required, ΔT30. Confirm the steel thickness, welding consistency, coating system, pressure testing, connection size and supplied brackets. A slightly cheaper unit can become expensive if output claims are inconsistent or packaging causes transport damage.
Choosing the right range for a market
A distributor usually needs a focused size matrix rather than every possible combination. Type 11 and Type 22 cover many mainstream requirements, while Type 21 or Type 33 can address projects with specific depth or output constraints. Type 10 is useful for specialist applications and easy-clean environments.
SUNLIKE manufactures heating radiators for international distributors and OEM customers. Product selection can be developed around target heat outputs, popular local dimensions, connection preferences, packaging and private-label requirements. A clear type strategy helps importers reduce slow-moving inventory while still covering the needs of installers and project buyers.