• The Problem Defined
• Government Standards
• Improving Indoor Air Quality
• Ventilation Problems In Closed Schools
• Ventilation Problems in Schools With Windows
• Temperature and Relative Humidity
• Copying Equipment
• Pesticides
• Vocational and Art Classes
• Science Rooms and Laboratories
• Air Quality During Renovation Work
• Coal-Fueled Boilers
• Pollution From Outside Sources
• Resolving Indoor Air Quality Problems

IMPROVING INDOOR AIR QUALITY

What can be done to improve indoor air quality?

Improving indoor air quality generally requires a two-pronged approach: proper ventilation and pollution prevention.

To be properly ventilated, a building must have a reliable supply of outside air that is sufficient for the number of building occupants, and that air must be properly distributed throughout the building. Any chemical and biological contaminants indoors will increase in concentration unless air is brought in from outside to dilute them.

How can poor ventilation be improved?

Providing adequate outside air in a building that has a mechanical ventilation system may require relatively simple changes in operation and maintenance,— or it may require major renovations if the system is not adequate to meet the building’s needs. In a building without mechanical ventilation, keeping the windows open, or opening them periodically in the winter, can regulate the supply of outside air.

For specialized activities that generate toxic pollutants —; such as the use of ceramic kilns, airbrush painting techniques or photographic developing equipment — local exhaust equipment vented directly to the outside should be provided to prevent contaminants from entering the room and being circulated throughout the building.

What about pollution prevention?

Although better ventilation will improve air quality, it also is essential to eliminate or minimize any sources of hazardous pollution in the building. Measures that prevent pollution at the source include:

• Selecting non-toxic or less toxic materials for use in shop and art classes.

• Choosing pest control techniques that minimize exposure to toxic chemicals.

• Selecting building materials and furnishings that emit the smallest possible amount of airborne contaminants.

• Banning indoor smoking in public buildings, as New York City has done.

It is also important for the custodian to implement and maintain a preventive maintenance program for the building and for all who use the school to maintain good housekeeping practices. The building maintenance program should also include controlling water leaks and infiltration and removing water-damaged and moldy carpeting, paper, books, plaster, sheetrock or other porous materials.

VENTILATION PROBLEMS
IN CLOSED SCHOOLS

Is ventilation a problem in the New York City school system?

Yes, particularly in the approximately 50 “closed” buildings that lack operable windows and depend entirely on mechanical ventilation. It’s also a problem in many of the nearly 1,100 other schools that rely primarily on open windows for ventilation. Of course, it is also a problem when staff must utilize rooms or spaces that were never designed to be occupied (e.g., bathrooms, storage closets, etc.).

Why did the DOE build schools with windows that can’t open?

To save money on heating and cooling. During the energy crisis of the 1970s, many buildings throughout the United States were designed without operable windows and with ventilation systems that limit the intake of outside air and increase the percentage of recirculated air. Since it is expensive to heat outside air before circulating it in winter (or to cool it in summer), minimizing intake lowers operating costs. Eliminating operable windows allows air intake to be controlled by a mechanical ventilation system without any interference by building users.

Experience demonstrated that closed buildings resulted in serious air quality problems. To combat them, the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE standard 62 – 1999) recommends supplying outside air so that carbon dioxide levels are maintained at concentrations below the sum of 700 ppm plus the outdoor carbon dioxide level (300 to 400 ppm). That comes close to the 1000 ppm corresponding to the NYC Building Code’s outside air requirements.

What types of ventilation problems are found in closed buildings?

The key problem is a lack of adequate outside air. Recirculating air already in the building, instead of bringing in some new air from outside, allows whatever indoor pollutants are present to increase in concentration.

Air quality problems also may develop when large rooms are subdivided to create more classrooms if the new spaces don’t have sufficient windows or vents for incoming and outgoing air. Poor maintenance — including a failure to change air filters frequently enough — is another source of poor air quality.

What can be done about such problems?

Proper maintenance is always important. In addition, in some closed buildings, the ventilation equipment can be adjusted to increase outside air intake. At a Bronx intermediate school, for example, staff comfort improved dramatically after the UFT convinced the Department of Education to direct the custodian to provide as much outside air as possible during the cold, dry months. (The DOE also replaced broken thermostats throughout the building.)

In other closed buildings, however, especially those operating far above the designed student capacity, the ventilation system lacks the ability to supply sufficient outside air. In such buildings, improving air quality may require major reconstruction, which is very expensive.

Continued