Heat Transmittance in buildings

Heat transmittance is brought about by Radiation of electromagnetic waves travelling at the speed of light hitting the building and the heat thus produced being conducted into the house. Radiation (InfraRed) itself does not have a temperature. Heat transmittance in a building can be calculated as follows:

Φ = A × U × (T₁ - T₂)

where Φ is the heat transfer in watts, U is the thermal transmittance, T₁ is the temperature on one side of the structure, T₂ is the temperature on the other side of the structure and A is the area in square metres.

energy efficient windows

A key measure for rating the energy efficiency of a product is its U value.

The higher the U value the more heat flows through a building component so a good value is a low one as you want to keep heat inside the building or outside depending on the time of year.

Living in a building that has low U values has a number of advantages:

1. It saves money on the energy bill
2. It helps preserve the environment
3. It is good for your health
4. It gives better indoor comfort