# Steam Radiators and Convectors - Heating Capacities

### Steam Heated Radiator

The heat capacity of a steam radiator can be expressed as

H_{ r }= q_{ s }h_{ s }λ_{ r }(1)

where

H_{ r }= heat capacity of radiator (kW, Btu/h)

q_{ s }= condensate rate (kg/h, lb/h)

h_{ s }= latent heat steam (2675 kJ/kg, 970 Btu/lb)

λ_{ r }= radiator temperature correction coefficient = 1 for room temperature 70^{ o }F (21^{ o }C) and steam temperature 215^{ o }F (100^{ o }C).

The radiator correction coefficient for other room and steam temperatures can be calculated

λ_{ r }= [( (215^{ o }F) - (70^{ o }F) )/(t_{ s }- t_{ r })]^{ 1.3 }(1b)

where

t_{ s }= average steam temperature (^{ o }F)

t_{ r }= room temperature (^{ o }F)

### Steam Heated Convector

The heat capacity of a steam heated convector can be expressed as

H_{ c }= q_{ s }h_{ s }λ_{ c }(2)

where

H_{ c }= heat capacity of convector (kW, Btu/h)

q_{ s }= condensate rate (kg/h, lb/h)

h_{ s }= latent heat steam (2675 kJ/kg, 970 Btu/lb)

λ_{ c }= convector temperature correction coefficient = 1 for inlet temperature 65^{ o }F (18^{ o }C) and steam temperature 215^{ o }F (100^{ o }C).

The convector correction coefficient for other room and steam temperatures can be calculated

λ = [((215^{ o }F) - (65^{ o }F) )/(t_{ s }- t_{ i })]^{ 1.5 }(3)

where

t_{ s }= steam temperature (^{ o }F)

t_{ i }= inlet temperature (^{ o }F)

## Related Topics

### • Heating

Heating systems - capacity and design of boilers, pipelines, heat exchangers, expansion systems and more.

### • Steam and Condensate

Steam & condensate systems- properties, capacities, pipe sizing, systems configuration and more.

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