The diagrams below indicates heat loss from uninsulated pipes with bare surfaces at still-air conditions and air temperature 70 oF (21 oC). The emissivity coefficient of the surface is 0.95.
Heat loss from pipes, tubes and tanks - with and without insulation - foam, fiberglass, rockwool and more.
Steam and condensate pipes - heat loss uninsulated and insulated pipes, insulation thickness and more.
Heat transfer and heat loss from buildings and technical applications - heat transfer coefficients and insulation methods to reduce energy consumption.
The radiation constant is the product between the Stefan-Boltzmann constant and the emissivity constant for a material.
Heat loss from uninsulated copper tubes vs. temperature differences between tube and air.
Heat loss from insulated and uninsulated, sheltered and exposed heated oil tanks.
Conductive heat losses through cylinder or pipe walls.
Heat emission from steam or water heating pipes submerged in oil or fat - forced and natural circulation.
Heat emision from steam or water heating pipes submerged in water - assisted (forced) or natural circulation.
Radiation emissivity of common materials like water, ice, snow, grass and more.
Heat transfer due to emission of electromagnetic waves is known as thermal radiation.
The amount of condensate generated in a steam pipe depends on the heat loss from the pipe to the surroundings.
Heat losses from un-insulated steam pipes.
Steam tracing of pipe lines can be done to maintain appropriate product temperatures.
The radiation heat transfer emissivity coefficients for some common materials like aluminum, brass, glass and many more.