Glossary

Engineered Systems, August, 2005

Here are some common abbreviations and terms found in the pages of Engineered Systems.

A

A/C--air conditioning ach--air changes per hour AE--architectural and engineering; or architect and engineer AFD--adjustable-frequency drive AHJ--Authority having jurisdiction AHU--air-handling unit ASD--adjustable-speed drive ASHRAE--American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. ATC--automatic temperature control

B

BACnet--a data communication protocol for building automation and control networks BAS--building automation system bhp--boiler horsepower; also, brake horsepower BMS--building management system

C

CAD--computer-aided design cfm--cubic feet per minute CHW--chilled water CMMS--computerized maintenance management system C[O.sub.2]--carbon dioxide COP--coefficient of performance

D

D-B--design-build db--dwbulb DDC--direct digital controls DID- design intent document DOAS--dedicated outdoor air system DOE--U.S. Department of Energy DX--direct expansion

E

EMS--energy management system EPA--U.S. Environmental Protection Agency

F

fpm--feet per minute FPT--functional performance test

G

gpm--gallons per minute

H

HEPA--high-efficiency particulate air HTML--hypertext markup language HTTP--hypertext transfer protocol HWR--hot water return HWS--hot water supply

I

IAQ--indoor air quality IS--information systems IT--information technology

L

LEED[TM]--Leadership in Energy and Environmental Design, a designation by the U.S. Green Building Council

M

MEC--mechanical, electrical, communication MEP--mechanical, electrical, plumbing MERV--minimum efficiency rating value

O

O&M--operations and maintenance oBIX Open Building Information Exchange OEM--original equipment manufacturer OA--outside air

P

PM--preventive maintenance PID--proportional, integral, derivative

R

rh--relative humidity RFP--request for proposal RFS--request for submittal ROI--return on investment RO--reverse osmosis RTD--resistance temperature detector

S

scfm--standard cubic feet per minute

T

TAB--testing and balancing TES--thermal energy storage

U

UL--Underwriter's Laboratory USGBC--U.S. Green Building Council UV--ultraviolet

V

VAV--variable-air volume VFD--variable frequency drive VSD--variable-speed drive

X

XML--extensible markup language

W

WAN--wide area network wb--wetbulb wc--water column wg--water gauge