chetanladha said:Hi.
Knowing the LRV, heat source and all other relevant details, how can we deduce the exact temp rise with black colour (or any other colour for that matter)??
Dadface said:If the body is painted black then you can get approximate answers by treating it as a black body(perfect absorber/radiator).For other colours you can refer to the heat absorption coefficient(emissivity)but I doubt if you can get perfect data because different paints,even those that might look the same,have different characteristics.To add to the complications some paints have spectral emissivities that are are temperature dependant.
It seems that you are tackling a problem that can very complicated.Radiation is not the only method of heat transfer since you also have convection and conduction and possibly evaporation/condensation.There are so many variables.
If you gave more details about what exactly it is you are trying to do people here might be able to give you more advice.Am I right in guessing that you are starting a project with an emphasis on practical work which is about comparing the radiation/absorption characteristics of different surfaces?
chetanladha said:Hi.
My work is very close to comparing the radiation/absorption characteristics of metal plate painted with different colours.
So, if there is a steel plate painted black, can i take the rise in temperature of paint to be the final temperature of the steel plate. (Assuming that the paint passes all of its heat to the parent metal.)
Tackling individual paint or steel plate if fine, but does the same hold true when you are talking about a steel plate painted black?
The color of paint can have a significant impact on its ability to absorb heat. Dark colors, such as black, absorb more heat than lighter colors because they absorb a wider range of light wavelengths. This means that black paint can absorb more heat from both visible and non-visible light sources, making it more effective at absorbing heat than lighter colors.
The specific heat capacity of black paint will vary depending on the type of paint and its composition. However, in general, black paint has a higher specific heat capacity than other colors because it can absorb more heat energy. This means that it requires more energy to raise the temperature of black paint compared to lighter colors.
To calculate the exact amount of heat absorbed by black paint, you will need to know the specific heat capacity of the paint, the temperature change, and the mass of the paint. The equation for calculating heat absorption is Q = m x c x ΔT, where Q is the heat absorbed, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
Yes, the amount of heat absorbed by black paint can vary depending on various factors such as the color of the surface the paint is applied to, the type of light source, and the environmental conditions. For example, black paint may absorb more heat on a sunny day compared to a cloudy day since there is more light energy available for absorption.
While black paint is known to be a good absorber of heat, it is not necessarily the most effective color for all situations. Other factors, such as the type of surface and the environment, can also affect the heat absorption capabilities of a color. For example, on a hot day, white paint may be more effective at reflecting heat from the sun and keeping a surface cooler compared to black paint.