Lexikon - U-value (W/(m2K))
It is a scalar size to measure the insulation features of components or material. The warmth transition coefficient (U-value) indicates how much warmth per degree temperature difference passes through one m² component size between the inside and the outside surface. The U-value replaces the well known K-value and is defined by new European regulations.
- Under insulation
It is wood protection and helps to protect against humidity on components of a roof construction or a ventilated facade. It also protects outer surfaces from wind and therefore from warmth loss.
- WSchVO 1995
It is the abbreviation for the warmth protection law of 1995 and is therewith the third step of the ordinance existing since 1978. This sets rules for warmth protection of buildings. The WSchVO 1995 was replaced in 2001 by the "EnEV". A house build with the standards of the WSchVO requires in the average 50 to 120 KWh heat warmth per m² utility area and year (KWh/(m²a)) -considering climate data and utilization behavior. This means an oil demand of 7 to 17 liters per m² utility area and year.
- Warmth bridges
They are part of the surface on which much warmth gets lost. There are geometrical, material reliant and convective ones:
a) Geometric: they emerge if the cold outer surface of a component is bigger than the area facing the inside (e.g. an outside corner).
b) Material reliant: they are areas on which materials with different heat conduction meet, with this warmth currents lead to cooling the inside, and
c) Convective: they are cracks trough which winds lead to ventilation warmth loss or dew in components and humidity. Besides loss of energy. There is danger in cooling of inner surfaces of components and therewith breakout of condensation fluid. The inner surface temperature of outside components may not decrease below 12.6 Celsius degree.
- Warmth profits
They are listed in a warmth calculation for the reduction of the heat energy demand. Warmth profits are internal warmth of persons, of devices, of lights, etc., and solar warmth.
