IAQ Calculator FAQ

This Calculator is used to quickly calculate and produce a professional report that shows acceptable Outside Air (OA) reductions when utilizing an effective air purification technology.

How To:

Basic Information Page

  • Your name and Company name will appear on the final report.
  • This email is used to send the report to, but will not show on the final report.

Zone Details Page

  • Try to be as accurate as possible. Please refer to the definitions below of the various input fields.

Recalculate Page

  • Only adjust the concentration levels of the outside contaminants if you have specific knowledge about the environment around the facility.
  • If any gas has an “x” in the Steady State acceptable column you will not be able to proceed until this is corrected. Adjust Zone Details such as the Desired Outside Air, Ventilation Effectiveness, etc. then hit recalculate.
  • If all gases show acceptable levels, feel free to adjust zone details or outside contaminant levels and hit recalculate until you are satisfied with the optimal configuration.

Results Page

  • This is a preview of your Zone Report. If you are unsatisfied with the reults, hit the “back” button to recalculate or select “Email PDF” to finish.
  • Multiple Zone Facilities: Each Report is based on a single Zone. To general multiple reports for the same facility simply complete your first Zone Report, select the “Email PDF” button, then select the “Create another report”. This will take you back to the Zone Details page with all of your information saved. Simply customize the Zone Details and repeat.

Definitions:

Zone Tag: Zone Tags are used to identify multiple zones within the same facility often associated with specific Air Handler Units (AHUs). You can generate multiple reports for different zones if needed.

Facility Type: Select the most appropriate facility type from the dropdown menu. This selection does not affect the results.

Level of Physical Activity: Identifying the level of physical activity/exercise within the zone is essential to calculate CO2 levels.

Zone Use: Select the most appropriate zone use from the dropdown menu. This selection does affect the results.

Zone Floor Area: Az = zone floor area, in square feet.

Zone Height: Average living spaces have between an 8-10 ft. ceiling height. Common areas and commercial spaces can vary significantly. Zone heights can differ slightly from living area heights.

Zone Max Occupancy: Pz = Peak zone occupancy, in number of people.

Supply Air: Vs = Supply air volume, in scfm (standard cubic feet per minute)

Desired Outside Air: Vo = the desired volumetric flow rate (CFM) of outdoor air using an air purification system to reduce Contaminant levels (Indoor Air Quality Procedure)

Ventilation Effectiveness: Ez = zone air distribution effectiveness. Accurate Ez value for stratified air distribution systems may justify reduction of minimum outside air (OA) required without compromising IAQ. Ez in breathing zones can often range from .75-1.05. Any value under 1.0 indicates that some fresh air was not mixed completely with room air, but went from inlet to outlet.

HVAC Flow Type: Variable Air Volume (VAV) is a type of heating, ventilating, and/or air-conditioning (HVAC) system. Unlike constant air volume (CAV) systems, which supply a constant airflow at a variable temperature, VAV systems vary the airflow at a constant temperature.

Outdoor Air Flow Type: Variable Air Volume (VAV) is a type of heating, ventilating, and/or air-conditioning (HVAC) system. Unlike constant air volume (CAV) systems, which supply a constant airflow at a variable temperature, VAV systems vary the airflow at a constant temperature.

Outside Air Drybulb: The dry-bulb temperature (DBT) is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture, in this case, measured in Fahrenheit at the intake.

Outside Air Wetbulb: The Wet Bulb temperature is the temperature of adiabatic saturation, in this case, measured in Fahrenheit at the intake. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow. Wet-bulb temperature is largely determined by both actual air temperature (dry-bulb temperature) and the amount of moisture in the air (humidity).

Coil Leaving Air Drybulb: The dry-bulb temperature (DBT) is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture, in this case, measured in Fahrenheit leaving the coils.

Coil Leaving Air Wetbulb: The Wet Bulb temperature is the temperature of adiabatic saturation, in this case, measured in Fahrenheit leaving the coils. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow. Wet-bulb temperature is largely determined by both actual air temperature (dry-bulb temperature) and the amount of moisture in the air (humidity).

Selected Air Contaminants: These 21 Gaseous Air Contaminants were selected based on their relevance to various industries.

Typical Outdoor Concentrations: Typical Outdoor Concentrations are based on US national averages; only adjust these values if you have specific knowledge about a Contaminant. Values are listed in Parts Per Million (PPM)

Maximum Threshold Value: The Threshold Limit Value (TLV) time weighted average (TWA) of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse health effects. Default values are taken from ASHRAE recommendations. Values are listed in Parts Per Million (PPM)

Reduced OA with IAQ Method: Shows the indoor Parts Per Million (PPM) values of each of the 21 Gaseous Air Contaminants after the outside air (OA) has been reduced and an effective air purification system (IAQ method) has been implemented to reduce the Contaminants.

Results – Is Steady State Acceptable at Reduced OA Levels?: A checkmark indicates that the indoor contaminant levels are still under the listed Threshold Limit Value (TLV) after the outside air (OA) reduction and air purification system (IAQ method). An “x” indicates that the contaminant levels are unacceptable.