Whether or not an interior space has good IAQ (indoor air quality) usually hinges on one thing: how much fresh air is being delivered.
According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), an office space should be receiving 20 cubic feet per minute (CFM) of fresh outdoor air per person and 140 CFM per 1,000 square feet of net floor space.
The purpose of these requirements is to dilute contaminants that are created by the worst indoor air polluters of all—us. It is meant to lower carbon dioxide, which we exhale with every breath. It is meant to dilute odors and various chemicals. And, of course, it is meant to whisk away the more unpleasant of smells associated with a group of people.
Sign # 1: You get more sleepy as the day progresses.
This could also be sensed as the indoor environment seeming more “stuffy”. This is the result of a buildup of carbon dioxide, which is a sign that not enough outdoor air is being brought into the space. Whereas CO2 is a harmless gas to humans in normal concentrations, it can cause sleepiness, headaches, and a sense of stuffiness. It also signifies that ASHRAE’s guidelines are not being met.
Sign #2: The thermostats in the space are set to “Auto”.
This is an extremely common mistake. When the ventilation unit is set to “Auto,” fresh air is introduced only when the thermostat calls for it. In other words, only when the system senses that the air needs to be hotter or colder. The rest of the time, no fresh air is brought in. Systems should be set to “On” in all but the most extreme situations (e.g. extreme heat or cold).
Sign #3: Itchy, watery eyes; throat irritation.
It should be said at the outset that these can also be symptoms of allergic reaction. Thus, one should see an allergist prior to pinning the blame on the air quality. That being said, high levels of ultra-fine particulate are known to cause the symptoms listed above. Ultra-fine particles are emitted from a variety of office and manufacturing equipment, such as printers, fax machines, and even cooking equipment.
Sign #5: Areas of the space are “Too Hot” or “Too Cold”
These are the most common complaints related to the indoor environment. For the most part, they result from an imbalanced system, or a system that has a design that was not meant for the current use of the space. A ventilation system designed for an empty new building is going to behave much differently when populated with cubicle walls, desks, equipment, and the like. These new “obstacles” can cause air coming out of the system to bounce or deflect – sometimes right onto someone’s work station, causing them to be cold. In another area, a person may be hot, because the designed system flow is blocked and cannot reach all occupants.
Source: www.blog.cashins.com; Zachary Keefe; October 18, 2013.