Air Quality in Residence Halls

Indoor Air Quality

Indoor Air Quality is a term used to describe several variables measurable in the indoor air and how they relate to the occupants’ comfort and health.  An evaluation of indoor air quality includes a visual assessment and measurement of primary indoor air quality indicators (carbon dioxide, temperature and relative humidity).  The initial assessment may indicate the need for additional evaluation. When considered together, all of these variables can give an indication of the quality of the air.

Comfort Level

The comfort level is a range of indoor air parameters that most people will perceive as comfortable. It is neither a danger level nor a level mandated by a regulatory agency. It is used as a guideline for occupant comfort only. For example, EPA recommends indoor air temperatures be maintained between 73.5° F and 79.5° F for occupant comfort. We know that temperatures outside this range are not dangerous as many people work outside or in specialty occupations that require them to labor in temperatures in the 90 – 100° F range in the summer or 50 – 30° F or colder in the winter. Obviously, one needs to dress appropriately but these temperatures are not dangerous if proper precautions are taken. Just as with temperatures, most indoor air contaminants have safe levels. Carbon dioxide is found naturally outside at about 400 ppm. The American Society for Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) recommends indoor air levels be maintained at or below 1000 ppm as a comfort level. OSHA standards allow workers to work in environments where carbon dioxide levels reach 5000 ppm.

Carbon Dioxide (CO2)

Carbon dioxide exists as a normal constituent of outside air and is commonly measured outside between 350 and 400 parts per million (ppm). As part of normal respiration, we inhale air to obtain oxygen and exhale carbon dioxide. Therefore, the more people you have in a given area, like a classroom, the more carbon dioxide will accumulate unless it is exchanged with outside air provided by the heating, ventilation and air conditioning (HVAC) system. As the carbon dioxide level rises, some people will start to notice changes in the “feel” of the room air. The room will start to feel stuffy, closed in and uncomfortable. Individuals may experience difficulty concentrating, become drowsy or even experience a slight headache. These reactions are commonly experienced as the carbon dioxide exceeds the 1000 ppm comfort level. Carbon dioxide is not regulated until it reaches 5000 ppm which is the level OSHA has set as allowable for a worker to be exposed to for up to eight hours a day. It is highly unlikely that the carbon dioxide level would ever approach the OSHA PEL in University buildings. Our goal, however, is to maintain our buildings below the comfort level. This way, we can provide a comfortable environment that is more productive and healthy.

Relative Humidity (RH)

Relative Humidity (RH) is the amount of moisture being held as water vapor in the air. When the air is too dry, below 20% RH, people become uncomfortable and may experience dry skin and respiratory irritation, dry, irritated eyes especially with contact users. When the RH is too high, (above 70%), mold and mildew may start to grow on organic materials including ceilings, wall, desks etc. The spores released from the mold and mildew can cause respiratory irritation or trigger allergy symptoms. We generally aim for a relative humidity of between 30% and 60% as an acceptable level. It is important to note that the humidity of outside air can affect the humidity of inside air and building occupants may need to provide dehumidifiers to control excessive humidity levels during certain seasons of the year.

Temperature (°F)

As all of us know, temperature is the measure of heat or cold in a given environment. Its importance is that of comfort more so than health. EPA and the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) have established a range of temperatures that seems comfortable for most people. It is at the temperature extremes that a health problems such as heat exhaustion and hypothermia occur. Keep in mind, that temperatures above 85° F may be uncomfortable but are not necessarily a health problem as people routinely work safely outside in 100° F+ temperatures.


Mold is a natural part of the environment and like other fungi, molds produce tiny spores to reproduce. Mold spores continually waft through the air, both indoors and out-of-doors. Mold spores can enter the indoor environment through open doorways, windows, and HVAC systems.  Spores can also attach to clothing, shoes, and pets and be carried indoors. Mold spores may be found lying dormant on almost every surface in a building. Unless large numbers of spores become airborne, there is usually little problem. However, when mold spores are on a surface with an appropriate moisture content, nutrients, and temperature, the spores will germinate, and mold will grow. Indoors, molds can grow on wood, paper, fabrics, carpet, foods, and other organic materials. There is no practical way to eliminate all mold and mold spores indoors. However, indoor mold growth can be controlled by controlling moisture. Mold spores will not grow if moisture is not present.  Causes of moisture problems include occupant-generated sources, floods, roof leaks, problems with drainage or plumbing, temperature gradients, and humidity. Exposure to mold and other allergens may cause a variety of health effects, or none at all. Some people are sensitive to mold and other allergens and can have symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin.  People with allergies tend to be more sensitive to molds.

How To Prevent Mold Growth

  • For rooms that have heating and ventilation control, set the thermostat between 68 – 72 degrees Fahrenheit. Do not turn the unit on an extremely cool or hot setting and then turn it off once it gets to the setting. Turning units off and on prevents proper air flow and stagnant air leads to odors and potential mold growth issues.
  • Do not block airflow from HVAC units with furniture, clothing, etc.
  • Air circulation helps prevent mold so please do not pack your closets and storage areas too tightly.
  • Keep all vents open and free of obstructions.
  • Avoid storing wet clothes/towels for extended periods of time as that will provide an environment conducive to mold growth.
  • Keep your windows closed. Allowing outdoor humidity to directly enter a room enhances the chances for mold growth.
  • Good housekeeping practices (vacuum floors, wipe down counters, clean up spills quickly, washout out refrigerators).
  • Empty all trash and recycling regularly.
  • Store food in airtight containers.

Testing For Mold

CDC does not recommend sampling for mold. If there is visible mold, it should be removed, and the moisture source resolved.  Since the effect of mold on people can vary greatly, you cannot rely on sampling and culturing to know your health risk.  Standards for judging what is an acceptable, tolerable, or normal quantity of mold have not been established.  The best practice is to remove any visible mold and work to prevent future growth by controlling the moisture source.

Reporting Issues

  • Report moisture intrusion issues (floods, leaks, problems with drainage or plumbing, excessive humidity, etc.) immediately to initiate responsive action. Also report other indoor air quality issues including visible mold growth, HVAC problems, and other maintenance issues for corrective action.
  • Report issues occurring via ECU Campus Living’s maintenance requests link, go to 
  • Initial requests for assistance should be through ECU Campus Living’s maintenance requests link, go to . For additional information, please contact the Office of Environmental Health & Safety at or 252-328-6166.