Book - School of Science and Technology

Combined radiant and convective heating 189Radiators in the second group are provided with more secondary surface and thuswill have a greater convective component in the total output. In at least two instances,the extent of the added surface and the minimal radiant output is such that theTable 7.5 Emissions from radiators for a temperature difference air to mean water of 60 KRadiatorFigureNo. Type Pattern DepthDimensions (mm)Range ofheightsRange ofemissions(kW/m 2of elevation)7.12 (a) Cast iron sectional (open) 2-column 70 430±980 1.87±2.104-column 160 430±980 3.41±3.586-column 250 280 5.437.12 (b) Cast iron sectional 2-column 71 430±980 2.29±2.32(flat front) 4-column 161 430±980 4.01±4.076-column 251 280 6.017.13 (a) Plain steel panel Single 51 300±750 1.31±1.46Double 82 300±750 2.13±2.427.13 (b) Steel sectional 2-column 110 450±1000 2.813-column 160 450±1000 3.60±3.755-column 250 300 5.947.13 (c) Steel panel with coil Figure 7.1 also 35 500±900 1.15±1.217.13 (d) Steel tubular with headers 40 mm crs for 98 400±1000 2.93±3.12elements 166 400±1000 5.16±5.2960 mm crs for 98 400±1000 1.95±2.09elements 166 400±1000 3.43±3.537.14 (a) Steel panel with surface Single 30 320±720 1.62±1.79added at rear Double 64 320±720 3.01±3.467.14 (b) Steel panel with added Single 40 300±1000 1.92±2.29rear waterways Double 80 300±1000 2.95±4.077.14 (c) Steel multi-panel with Double 150 100±200 6.68±7.82extensive added surface Treble 225 100±200 9.88±11.087.14 (d) Grid waterway in Slim 70 370±1020 2.48±2.53perforated case Deep 172 370±1020 3.27±3.627.15 (a, b) Aluminium sectional with Open top 95 430±690 4.52±4.65flat panel front Closed top 160 285±435 6.68±6.737.15 (c) Aluminium finned unit in With damper 30 300±750 2.92±2.97casingat baseTable 7.6 Temperature corrections (Dt/60) 1:3K 0 1 2 3 4 5 6 7 8 930 0.41 0.43 0.44 0.46 0.48 0.49 0.51 0.53 0.55 0.5740 0.59 0.61 0.63 0.65 0.67 0.69 0.71 0.73 0.75 0.7750 0.79 0.81 0.83 0.85 0.87 0.90 0.92 0.94 0.96 0.9860 1.00 1.02 1.04 1.07 1.09 1.11 1.13 1.16 1.18 1.2070 1.23 1.25 1.27 1.30 1.32 1.34 1.37 1.39 1.41 1.4380 1.45 1.48 1.50 1.52 1.55 1.57 1.59 1.62 1.65 1.6790 1.69 1.72 1.74 1.77 1.80 1.82 1.84 1.87 1.89 1.92100 1.94 1.96 1.99 2.02 2.05 2.07 2.10 2.12 2.15 2.18110 2.20 2.22 2.25 2.28 2.29 2.33 2.36 2.38 2.41 2.43