Carbon dioxide is a colourless gas formed during the combustion of any material containing carbon and an important green house gas. Sources of CO2: ➔ All energy production using combustion emits carbon dioxide.

Volatile Organic Compounds(VOCs) are a large group of chemicals that are found in many products we use to build and maintain our homes. Once these chemicals are in our homes, they are released or “off-gas” into the indoor air we breathe.

CFM is an abbreviation for cubic feet per minute(cu ft/min). When used in the context of a particle counter's flow rate, it is a measurement of the velocity at which air flows into the sample probe.

Particulate matter sensor PM 2.5. ➔Monitors and controls the concentration of particulate matter precisely. ➔ Based on the optical principle of scattered light for particle detection.

True HEPA – A consumer air filter labelled True HEPA should conform the closest to the DOE standard for a HEPA air filter. At its highest efficiency, it should remove 99.97 percent of all particles that are 0.3 microns in size.