Application to the home

We heat our homes to stay warm, no matter what the outside temperature. If it gets colder outside, the inner temperature stays the same, but we need more energy to maintain that temperature. This is because heat loss is greater when the temperature difference between the inside and outside is larger so more heat is lost and we need to produce more heat to stay warm inside.

The most heat is lost through the walls because this has the largest area exposed to the climate with windows providing the next largest source of heat loss.

To reduce heat loss much will depend upon the age of the dwelling as newer buildings will have a much higher standard of insulation than older dwellings. Some aspects of reducing heat loss are easy but others will require the help of specialists.

Not all buildings have the same heat insulation standard; older houses throughout the EU tend to have less insulation and newer houses have much more. For example prior to 1965 there was no formal requirement to install any insulation in UK homes but today it is recommended to have 250 mm minimum insulation in the gap between the ceiling and the roof, 50 mm or more insulation in the walls and 100 mm beneath the floor. With new homes not only can the building be well insulated it can also be orientated to maximise solar gain during the winter months.

The heat loss of a building can be calculated using the building thermal characteristics and the eheat software program. (Link to eheat introduction)

Effect of climate

The major influences are:

• proximity to the sea - either the Mediterranean or North Seas which moderate the extremes in temperature during both winter and summer
• distance form the equator which results in lower elevation of the sun and so less solar gain at any time of the year
• elevation above sea level where upland or mountainous areas are colder due to a higher loss of heat radiation at night
• presence of wind which can increase the rate of heat loss through the building fabric producing a 'wind chill' factor; coastal areas tend to have more wind than inland areas because of the difference in temperature between the land and sea
• rain has much the same effect as wind in increasing the heat loss through conduction by removing the 'warm' layer of air adjacent to the building fabric producing a 'rain chill' factor
• if both rain and wind are present then the 'temperature chill' factor is enhanced; this is a particular problem in the north west regions of the UK where there is the likelihood of both wind and rain which can result in moisture penetration of the building fabric leading to dampness and condensation

Environmental impact

Externally there are no environmental impacts. Internal impacts can arise in some coastal areas of the UK where the combined influence of wind and rain may result in moisture penetration across the thermal gap between the inner and outer brick layer once the cavity has been insulated.

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