MIL-HDBK-1011/2
Envelope-dominated buildings. A building in which the loads created by the
external conditions are greater than the loads created by internal sources.
Fenestration.
The design or placement of windows in a building.
First-order weather station. A major weather station at which a full set of
surface observations are taken on an hourly or three-hourly basis.
Heat capacity. The ability of a material to store heat for a given change in
its temperature. Among building materials, dense materials have high heat
capacities.
Humidity ratio
(W). For any temperature and humidity combination, the ratio
of the mass of
water vapor to the mass of the dry air with which it is mixed.
It is shown on
the horizontal lines of the psychrometric chart and read along
the right-hand
vertical axis. It is also known as absolute humidity.
Infiltration. Unwanted air exchange between the building interior and
exterior, resulting from pressures caused by wind and interior-exterior
temperature differentials. The primary difference between the usual
definitions of infiltration and ventilation is that infiltration is
undesirable and uncontrolled, whereas ventilation is desirable and
controllable.
Infiltration-resistant envelope. A building envelope designed to limit air
changes to less than 0.5 per hour. An infiltration-resistant envelope is
required in buildings that have mechanical air conditioning or heating
systems, and in climates where the temperatures drop low enough that
unrestricted air movement would cause uncomfortably low conditions within the
building.
Insulation.
Capacity of materials to retard heat flow.
Life-cycle cost (LCC) analysis. The total cost of a system over its
economically useful life. It includes the appropriate summation of all costs
expected to be incurred as a result of choosing and implementing any
particular plan or design over the life of the facility.
Load. The energy required within a building space to maintain interior
Mean radiant temperature. The uniform surface temperature of an imaginary
black enclosure that exchanges the same heat by radiation as the actual
non-uniform environment.
Met. A unit of human metabolic rate. One met is equivalent to 58 watts/m.2-
of body surface, or 50 kcal/h*m.2- of body surface, or 18.4 Btu/h*ft.2- of
body surface.
Natural cooling strategy.
A method for building cooling that does not use
purchased energy sources.
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