Physics - Heating and Insulating Buildings (AQA)

This is the point that U-values step in! These are a measure of how fast heat can pass through a material. Building materials have been tested and their U-values worked out. A lower U-value indicates that heat only passes through the material slowly, therefore the material is better at insulating than one with a high U-value, and vice-versa. You don't need to know any specific U-values or how they are calculated.

Heating well insulated buildings requires less energy overall and so saves money on the heating costs. It also helps to reduce the emissions of carbon dioxide. Unless the building is heated by a non-polluting supply of electricity or by geothermal energy, somewhere down the line carbon dioxide will be released into the air. Let's take for example using electric storage heaters. These transfer electrical energy into heat, taking their electricity from the National Grid. Most National Grid electricity is produced in conventional power stations which release large quantities of carbon dioxide into the air. Using gas or oil fired central heating systems puts carbon dioxide into the air directly.

Using wood fired heating is more environmentally friendly as the carbon dioxide released is called current carbon. In other words, it is carbon from the present time rather than being from millions of years in the past, as happens when burning fossil fuels. For hot water, solar panels on the roof of a building use the Sun's heat instead of burning fuels.