The YES Series of IAQ Monitors are essential for those responsible for conducting Indoor Air Quality Investigations. These instruments are specifically designed to measure and record the quality of indoor air in offices, buildings, homes, schools, parking garages, ice rinks, etc.


What is indoor air quality?
What is an IAQ Monitor and how can it help me?
When should you purchase an IAQ Monitor?
Who uses these monitors?
Why measure Temperature and Relative Humidity?
Why use Carbon Dioxide Levels to determine ventilation?
Facts on CO2
Poor indoor air quality causes the following problems:
Sick Building Syndrome
Building-Related Illness




Indoor air quality is the physical, chemical, and biological characteristics of indoor air. This environment is created by the interaction of the site, the climate, the building system, the potential contaminant sources (ie: furnishings, moisture sources, work processes and activities, and outdoor pollutants) and the building occupants.


An indoor air quality monitor samples the air continuously until downloaded; producing an analysis of the air quality based on the channels/gases supplied. YES Monitors measure IAQ on 3 basic levels; Temperature, Relative Humidity and Carbon Dioxide. By recording samples from all three variables simultaneously over a period of time, one is able to analyze where and when the air quality is poor in the workplace. Once the source has been determined then proper ventilation can be installed or altered.


Prior to introducing IAQ monitors into the investigation, one should have a comprehensive understanding of how the building operates and the nature of the complaints. An overview of the ventilation system will help to define where you should place the YES Air Quality Monitors to best address the issues at hand.


Initially these monitors were developed to assist property managers, building maintenance staff, health and safety officials, and consultants working in the occupational environment field. Although now various companies, corporations and schools use IAQ monitors to ensure proper air quality in the workplace.


ASHRAE Standard 55-1992, Thermal Environmental Conditions for Human Occupancy, sets guidelines intended to achieve thermal conditions that at least 80% of the occupants would find comfortable.
ASHRAE Relative humidity levels are recommended between 25-60%.
Increases concentrations of microbiological contaminants.
**Low RH causes skin to become dry leading to chapping and irritation, increases static electricity hindering computer operation.
**High RH levels can result in condensation and thus the development of molds and fungi.
High temperature and humidity levels can increase the concentrations of some pollutants. To obtain an accurate reading of pollutants levels, it is necessary to take into account these levels and balance the temperature and relative humidity with the carbon dioxide levels.



Carbon dioxide is an odourless, colourless gas produced through human metabolism. This provides the most accurate readings for determining when ventilation should be increased and decreased. Saving energy and improving air quality concurrently. High CO2 levels usually coincide with high indoor contaminates, due to a problem with the HVAC system.



Producers of CO2: people and combustion of fossil fuels (gas & oil furnaces/heaters)

The average person performing light office work produces carbon dioxide at a rate of 0.3L/min.

ASHRAE recommends 10 L/s per person

Normal part of the atmosphere at 330 - 350 ppm

Acceptable Office levels 600 - 800ppm


Many experience these symptoms without realizing that they can be alleviated through proper ventilation. ~

Sick Building Syndrome
A set of symptoms related to chemical, particulate or biological exposure that cannot be related to a specific cause but are alleviated when the occupant leaves the building. Individuals report symptoms such as headaches, nausea, fatigue and drowsiness, to eye, nose, and throat irritation.

Building-Related Illness
A specific illness with a known cause that is a result of exposure to an indoor agent. Examples are Legionnaire's disease and Pontiac Fever.
YES Environment Technologies Inc.
#145 - 7391 Vantage Way
Delta, BC, Canada
V4G 1M3


Toll Free: 1-877-940-7007
Phone: 604-940-7007
Fax: 604-940-7044

Email: fbritton@yestek.com