Warmer Worcestershire
Heat Loss Map

About thermal data

The thermal data used in the Warmer Worcestershire project is collected by a thermal camera on board an aeroplane. It measures the amount of infra red being emitted by surfaces - the emissivity, which can be interpreted as the amount of heat being given out. An average emissivity value is calculated for each building, relative to the rest of the area surveyed, which is then translated to a colour on the map. The colour assigned to your home may be a helpful indicator of how well insulated it is.

The following factors can influence the readings picked up by the thermal camera:

• Building construction and materials directly affect the thermal values of a roof, as some materials are capable of absorbing more heat and/or retaining heat for longer. For example a slate roof may appear to give out less heat than a concrete tiled roof.
• Surface colour can affect the actual temperature: dark surfaces tend to absorb and retain more heat than lighter coloured ones.
• Heat sources such as flues and chimneys can increase the average temperature of a roof.
• Surface moisture and standing water on surfaces increases the values picked up by the thermal sensor, showing the roof to be warmer.
• High levels of dirt or profuse mould growth may give a higher reading than a clean surface, making the roof appear warmer than it is.
• The amount of heat emanating from roofs may be affected by nearby tree canopies or vegetation, as moisture contained in them will emit higher values, increasing the average temperature of a roof structure.

The colours shown on the map are a snapshot of one point in time - i.e. the evening the data was collected. If your home is displayed as red or brown, it is losing higher than average heat through its roof. This may be because of poor insulation, inefficient heating, an intense heat source (such as an open fire) or simply because a lot of people were in the property on the night of the survey. Yellow or green indicates that your home is losing less heat, perhaps through better insulation or having the heating set to a lower temperature.