Steam Radiators and Convectors - Heating Capacities
Steam radiators and steam convectors - heating capacities and temperature coefficients.
Steam Heated Radiator
The heat capacity of a steam radiator can be expressed as
Hr = qs hs λr (1)
where
Hr = heat capacity of radiator (kW, Btu/h)
qs = condensate rate (kg/h, lb/h)
hs = latent heat steam (2675 kJ/kg, 970 Btu/lb)
λ r = radiator temperature correction coefficient = 1 for room temperature 70 oF (21 oC) and steam temperature 215 oF (100 oC).
The radiator correction coefficient for other room and steam temperatures can be calculated
λr = (((215 oF) - (70 oF)) / (ts - tr ))1.3 (1b)
where
ts = average steam temperature (oF)
tr = room temperature (oF)
Steam Heated Convector
The heat capacity of a steam heated convector can be expressed as
Hc = qs hs λc (2)
where
Hc = heat capacity of convector (kW, Btu/h)
qs = condensate rate (kg/h, lb/h)
hs = latent heat steam (2675 kJ/kg, 970 Btu/lb)
λc = convector temperature correction coefficient = 1 for inlet temperature 65 oF (18 oC) and steam temperature 215 oF (100 oC).
The convector correction coefficient for other room and steam temperatures can be calculated
λ = (((215 oF) - (65 oF)) / (ts - ti ))1.5 (3)
where
ts = steam temperature (oF)
ti = inlet temperature (oF)
