Initial Thermal Emittance

Initial Thermal Emittance is a measure of the ability of a roofing material to emit heat that has been absorbed from the sun. It is a key factor in determining the energy efficiency of a roofing system and can play a significant role in reducing cooling costs.

Initial Thermal Emittance is expressed as a percentage and is measured using a spectrophotometer, which measures the amount of heat that is emitted by the roofing material. The higher the initial thermal emittance, the more effective the roofing material is at emitting heat and reducing the amount of heat that is absorbed by the building.

Roofing materials with high initial thermal emittance, such as light-colored metal roofing or reflective coatings, are often used in warm climates to help reduce cooling costs and improve energy efficiency. Dark-colored roofing materials, on the other hand, typically have low initial thermal emittance and can absorb more heat, making them less energy-efficient.

It’s important to note that initial thermal emittance is just one factor in determining the energy efficiency of a roofing system. Other factors, such as the type of insulation, the type of roof deck, and the ventilation system, can also play a role in determining a roof’s energy efficiency.