Abbreviations. Honeywell AUTOMATIC CONTROL SI Edition

INDOOR AIR QUALITY FUNDAMENTALS

INTRODUCTION

This section provides basic information on Indoor Air Quality

(IAQ) and suggested control solutions. The causes and effects of several contaminants are discussed. These contaminants provide reason for concern about IAQ. Also included are recommended or required approaches to IAQ compliance and general approaches to preventing and controlling IAQ problems.

In addition, typical graphic displays are included illustrating the usefulness of an operator interface to allow pinpointing and correcting any problems that might cause degradation of IAQ.

Displays, requiring acknowledgment, can also be provided to alert the operator that periodic maintenance of IAQ is required.

The issue of indoor air quality (IAQ) has moved from virtual non-existence to a major concern over the last twenty years.

Measures taken to offset increasing energy costs since the 1970s, increasing use of synthetic materials in building construction and maintenance, compressed construction schedules, and reduction in operational maintenance resulting from competitive pressures have made IAQ a major problem for the building designer, operator, and owner.

A correctly designed control system properly applied to a well designed HVAC system can ensure optimal IAQ, which in turn will ensure occupant comfort and improved employee productivity. A poorly designed, installed, or maintained control system can reduce IAQ below acceptable levels, resulting in reduced productivity, increased employee health costs and building maintenance costs, and major legal costs.

DEFINITIONS

To control IAQ it is necessary to understand the terms commonly in use by the various agencies involved in industry and government which relate to the many disciplines involved.

Aerosol: Liquid droplets or solid particles, suspended in air, that are fine enough (0.01 to 100 micrometers) to remain dispersed for a period of time.

Air cleaner: A device that actively removes impurities from the air. Includes particle filters, gas phase filters and electronic devices.

Air quality standard: A government-mandated regulation which specifies the maximum contaminant concentration beyond which health risks are considered to be unacceptable.

Allergen: A substance that can trigger immune responses resulting in an allergic reaction; also known as antigen.

Bacteria: One celled organisms which are members of the protista, a biological classification.

Bakeout: A technique for reducing emissions of new construction in which the building temperature is raised (usually to at least 32

°

C) for several days to enhance emissions of volatile compounds from new materials, while running the ventilation system at full capacity to exhaust the emissions.

Bioaerosols: Airborne microbial contaminants, including viruses, bacteria, fungi, algae, and protozoa. The term also refers to the reproductive units, metabolites, and particulate material associated with these microorganisms.

Biocontaminant: Contaminants which are either life forms

(molds of the genera aspergillis) or are derived from living things such as rodent droppings.

Building-related illness: A diagnosable illness with identifiable symptoms whose cause can be directly attributed to airborne pollutants within the building (e.g.,

Legionnaires disease, hypersensitivity pneumonitis).

Carcinogen: An agent suspected or known to cause cancer.

Commissioning:

• Building: The process of designing, achieving, verifying, and documenting the performance of a building to meet the operational needs of the building within the capabilities of the design and to meet the design documentation and the owners functional criteria, including training of operating personnel.

• HVAC System: The process of documenting and verifying the performance of HVAC systems so that systems operate in conformity with the design intent.

Contaminant: An unwanted constituent that may or may not be associated with adverse health or comfort effects. See

Pollutant.

Decay rate: The rate at which the concentration of a compound diminishes.

Dilution: The reduction of airborne concentration of contaminants through an increase in outdoor air supplied to the space.

Dioctyl phthalate: An oily liquid used in testing filters.

ENGINEERING MANUAL OF AUTOMATIC CONTROL

151