Air balancing to achieve proper air circulation in the office, business, or retail space
ASHRAE has set guidelines for the amount of air circulation in a workspace is the document: ANSC/ASHRAE Standard 62.1-2016 titled, “Ventilation for Acceptable Indoor Air Quality.”
This document referred to as “ASHRAE 62” is intended to “specify minimum ventilation rates and other measures intended to provide indoor air quality that is acceptable to human occupants and that minimizes adverse health effects.”
It sets a recommended level of outdoor air for a wide variety of different types of building occupancy:
The Standard 62 also recommends the maximum occupancy density per 1000 ft2.
These limits were set under normal occupant conditions. The current COVID-19 conditions must be considered at present.
The consensus under these unusual circumstances must be considered the minimum levels with the ideal situation is double these recommended levels or the maximum allowable amount of outside air that the system can achieve while still maintaining the proper level of heat or air conditioning to achieve 68°F to 75°F.
Measurement of the amount of air circulation can be achieved through the use of proper ventilation measurement equipment. For office diffusers, the best instrument is a BALOMETER—a device that can be placed on a ceiling, wall, or floor diffuser to directly measure the CFM (cubic feet per minute) of air being supplied or exhausted from the space. Then the air changes per hour (ACH) can be calculated and the CFM/person can also be determined.
Other measurement equipment (velometer, Thermo anemometer) are used to directly measure the supply and exhaust of air handling systems.
There are also recommended levels of ACH for a variety of spaces.
Air balancing can be performed during occupancy or when not occupied (as long as the air handlers can be adjusted to occupancy levels).
Total air movement in an office building, manufacturing, warehouse, or retail space can also be measured.
SPECIAL NOTE: Our objective in evaluating HVAC systems is to address the health and safety concerns of the occupants. We do not propose to be specialists in the operation and maintenance of such systems!