Heating demand

If buildings are classified by their energy demands, one included parameter is the yearly heating requirement. Energy requirements for warm water, household technology and air-conditioning units during the summer are not included in this parameter.

The yearly heating requirement is the amount of energy that the heating system makes available in order to heat all heated spaces in one year. It is expressed by the units “KWh/m²*a” (kilowatt hour per square meter per year). However, one must only include the floor area of heated rooms when considering this calculation, and not necessarily all areas of a building (not, for example, a basement).

The heating requirement consists of both the transmission heating requirement (the heat that is lost through walls, windows and the roof) and the ventilation-heating requirement. Not included are separate internal sources of heat (i.e. body heat, appliance heat) and passive sources of heat (i.e. sunlight coming through a south-facing window).

The current heat conservation ordinance in Germany exactly defines the calculation of the yearly heating requirement. The future energy saving ordinance will set new limits.

See also:

Low Energy Building

Passive Energy Building

Zero Energy building

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