Basic Documentation
Table Of Contents
- About this Application Guide
- Chapter 1–Introduction
- Chapter 2–Goals of the Laboratory Environment
- Chapter 3–Unique Ventilation Needs of a Laboratory Facility
- Chapter 4–Ventilation Systems Classification
- Chapter 5–Laboratory Facility Exhaust Systems
- Chapter 6–Laboratory Containment Units - Ventilation
- Chapter 7–Room Ventilation, Makeup Air, and Pressurization Control Systems
- Chapter 8–Laboratory Temperature and Humidity Control Systems
- Chapter 9–Laboratory Emergencies - Ventilation System Response
- Chapter 10–Laboratory Ventilation System - Validation
- Chapter 11–Laboratory Ventilation System - Commissioning
- Glossary
- Index
Glossary
This glossary describes various terms and acronyms used in this application guide. For a
comprehensive listing of building control terminology, see the Technical Glossary of Building
Controls Terminology and Acronyms (125-2185).
ACH
See air changes per hour.
AHU
See air handling unit.
air changes per hour (ACH)
Number of times a volume of air, equal to the volume of the space, is moved through the
space each hour. To determine this number, the total volume of the space is first calculated
by multiplying the width, height, and length together. Then this total volume is divided by 60
to determine the cubic feet per minute necessary to produce one ACH. Multiplying the cubic
feet per minute (cfm) by two yields the cfm necessary to produce a ventilation rate of two
ACH, etc.
air handling unit (AHU)
Mechanical system that moves and conditions air to meet the comfort and ventilation
requirements of a facility. Usually includes an outside air intake provision, dampers, filters,
heating and cooling coils, a supply fan to move the air, and associated sheet metal ductwork
to interconnect and contain these components. An AHU may also have a return fan to draw
air out.
analog controller
Electronic or mechanical controller that transforms an input signal from a sensor into the
required output control signal. A mechanical analog controller uses mechanical elements,
such as bellows, springs, levers and cams, to create the control output. An electronic analog
controller uses electronic amplifiers, linearizers, and other special purpose electronic
components to process the incoming signal into an appropriate control output signal.
anemometer
Instrument that measures airflow velocity. For ventilation applications, the measurement is
usually in feet per minute (fpm). A "hot wire" or "thermo" anemometer is normally used
measure fume hood or bio-safety cabinet face velocity, since it can measure a wide range of
air velocities with excellent accuracy.
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