Glossary
|
The terms and definitions included
in this glossary were taken from "ASHRAE Terminology of Heating, Ventilation,
Air Conditioning & Refrigeration".
To access the complete glossary please
visit ASHRAE's Bookstore.
|
|
You can always search for terms. |
|
Submit Term |
|
| P |
| Pages: «1 2 3 4 5 6 7 8 » |
| pasteurization |
heat treatment of a fluid, usually at 130 to
160°F (55 to 70°C) killing bacteria, as in milk, without greatly changing its
chemical composition, and greatly extending its shelf life. |
| | |
| pcm |
phase-change material. |
| | |
| PD | 1. pressure dependent.
2. pressure difference (Dp).
3. pressure drop.
4. partial derivative (piping). |
| | |
| penthouse | roofed structure incorporating louvers or louver
blades in all or part of the walls, and usually designed to be on the roof of a
building. |
| | |
| perforated ceiling | one composed of perforated panels used to
distribute the air uniformly throughout the ceiling or portion of the ceiling |
| | |
| performance |
manner in which an individual, a building, a
system, or a component fulfills specified behavior. |
| | |
| peripheral equipment (computer) |
auxiliary machines that may be placed under the
control of a central computer. Examples include magnetic tape drives and
printers. Peripheral equipment may be used on-line or off-line depending on
computer design, job requirements, and economics |
| | |
| perm |
empirical unit of water-vapor permeance; one
perm = one grain (avoirdupois) of water vapor per hour flowing through one
square foot of a material or construction induced by a vapor-pressure
difference of one inch of mercury across the two surfaces. Note: Mass flow rate may be restated in other units consistent with
the defined units. One perm is the generally accepted maximum allowable permeance
value for the residential building envelope in a 5000 heating degree-day
climate. |
| | |
| permafrost |
in polar regions, and at some high-altitude
areas, perennially frozen soil. Note: It may have an active layer of varying
thickness at the surface, and it is this active layer that causes most of the
difficulties with permafrost. |
| | |
| permeability | time rate of water-vapor
transmission through unit area of flat material of unit thickness induced by
unit vapor pressure difference between two specific surfaces, under specified
temperature and humidity conditions. When permeability varies with
psychrometric conditions, the spot or specific permeability defines the
property at a specific condition. Note:
Permeability is a property of a material, but the permeability of a body that
performs like a material may be used. Permeability is the arithmetic product of
permeance and thickness |
| | |
|
|
Resources 
English RSS
