Kartell K-Rad Type 21 Double Panel Single Convector Radiator 900mm x 500mm

The Kartell K-Rad Kompact P905K is a Type 21 double panel, single convector radiator, 900 × 500 mm, giving 941 W (3209 BTU/h) at ΔT50. Two water-carrying panels with a single bank of convector fins sit in a 70 mm case: 941 W against 649 W for a Type 11 the same size, for 14 mm more depth. Nett weight is 21.85 kg and it holds 3.8 litres of system water. Type 21 double panel900 × 500 × 70 mm941 W at ΔT50EN 442 testedWhite enamel RAL 901610-year guarantee 3209 BTU/h Output at ΔT50 — 941 W 21.85 kg Nett weight — holds 3.8 l EN 442 Tested and certified 10 years Manufacturer guarantee Applications & suitability Where it goes Wall-hung on a sealed or open-vented wet heating system, fixed no lower than 100 mm off the finished floor. At 900 mm high it needs a clear wall rather than an under-window gap. Typical job A room needing roughly 941 W on a 70 °C mean water temperature, or 1205 W where the system runs at 80 °C. Straight swap for a tired 900 × 500 panel of the same size. Works with / replaces Pipe centres are 845 mm with a wall-to-centre of 65 mm or 80 mm, so it lines up with most existing 900 mm-high panels. Case depth is 70 mm against 56 mm for a Type 11 and 105 mm for a Type 22. When not to choose this The 941 W figure is at ΔT50. Run a heat pump at low flow temperatures and it falls hard — Kartell’s own correction factor at ΔT30 is 0.515, so you would get about 485 W from this radiator. Size at the ΔT you will actually run, and step up to a Type 22 or 33 if the load needs it. Key specifications Brand Kartell Model K-Rad Kompact P905K Radiator type Type 21 — double panel, single convector Heat output Output at ΔT50 941 W (3209 BTU/h) Output at ΔT60 1205 W (4111 BTU/h) Size and weight Dimensions (H × W × D) 900 × 500 × 70 mm Centre distance 845 mm Wall to centre 65 or 80 mm Weight 21.85 kg Water content 3.8 l Build and rating Max working pressure 10 bar Max working temperature 120 °C Finish White enamel, RAL 9016 Standard EN 442 Warranty 10 years Installation & compatibilityFix no lower than 100 mm from the finished floor. Allow 35 mm from the wall to pipe centre for a manual valve, or 45 mm for a TRV. Kartell requires the system to be cleansed and dosed with inhibitor to BS 7593:2019 — skipping it invalidates the guarantee, which covers product replacement only. Leave the protective packaging on until the radiator is fixed and the tappings are cut.Related & next steps Need more output? The Type 22 at the same 900 × 500 mm gives 1225 W at ΔT50, in a 105 mm case. View Type 22 Tight on space? The Type 11 is 56 mm deep and gives 649 W at ΔT50 — slimmer, but less heat. View Type 11 Other sizes Type 21 runs 400–900 mm high and 400–2200 mm wide, from 413 W to 3114 W at ΔT50. Browse radiators