Hi!
1. R-Value - a standardized rating for insulating materials
R value is essentially the measure of the resistance to the conductive flow of heat that is determined by the thickness of a material. Different materials are allocated different R values in accordance with the degree of insulation they offer, such as a window, or a wall. It can be said to be the degree of insulation a layer of material offers, and the greater the R value, the higher the resistance it offers to the flow of heat, meaning better the insulation
2. Thermal Equilibrium - when two materials in contact are at the same temperature
Thermal equilibrium is a state when there is no net flow of thermal energy between two materials that are in contact through a pathway that offers thermal conductivity, or in more simple terms permeable to heat. If the temperature of a system is temporally and spatially consistent, the system is said to be in a thermal equilibrium.
3. Insulation - any material that reduces loss of energy due to heat flow
Insulation is when a material prevents the flow or passage of thermal energy or stops heat flow by some degree from one environment to another. For instance, a blanket offers insulation to the body by impairing the flow of heat from the body to the surrounding air. The greater the insulation, the less would be the flow of heat or thermal energy from one place to another.
4. Thermal Conductivity - a physical property of materials that relates its ability to conduct thermal energy
Thermal conductivity is a property of a material that deals with its ability to conduct heat, or thermal energy. The higher the thermal conductivity of a material, the greater would be the heat transfer within the material. For instance, a metal has a higher thermal conductivity that wood, meaning wood allows a lower transfer of heat through it. This is the reason why most cooking utensils such as spatula have a wooden base, instead of a metallic base.
Hope this helps!
