Any indoor air quality management system will be successful only if it is organized to fit your specific building. It would not be appropriate to prescribe any single approach.

According to the EPA’s “Building Air Quality: A Guide for Building Owners and Facility Managers:” Indoor air quality can be affected both by the quality of maintenance and by the materials and procedures used in operating and maintaining the building components including the HVAC system.

Facility staff who are familiar with building systems in general and with the features of their building in particular are an important resource in preventing and resolving indoor air quality problems.

Facility personnel can best respond to indoor air quality concerns if they understand how their activities affect indoor air quality. It may be necessary to change existing practices or introduce new procedures in relation to the following: Equipment operating schedules: Confirm that the timing of occupied and unoccupied cycles is compatible with actual occupied periods, and that the building is flushed by the ventilation system before occupants arrive. In hot, humid climates, ventilation may be needed during long unoccupied periods to prevent mold growth.

Control of odors and contaminants: Maintain appropriate pressure relationships between building usage areas. Avoid re-circulating air from areas that are strong sources of contaminants (e.g., smoking lounges, chemical storage areas, beauty salons). Provide adequate local exhaust for activities that produce odors, dust, or contaminants, or confine those activities to locations that are maintained under negative pressure (relative to adjacent areas).

For example, loading docks are a frequent source of combustion odors. Maintain the rooms surrounding loading docks under positive pressure to prevent vehicle exhaust from being drawn into the building. Make sure that paints, solvents, and other chemicals are stored and handled properly, with adequate (direct exhaust) ventilation provided.

Ventilation quantities: Compare outdoor air quantities to the building design goal and local and State building codes and make adjustments as necessary. It is also informative to see how your ventilation rate compares to ASHRAE 62-1989, because that guideline was developed with the goal of preventing IAQ problems.

HVAC equipment maintenance schedules: Inspect all equipment regularly (per recommended maintenance schedule) to ensure that it is in good condition and is operating as designed (i.e., as close to the design set points for controls as possible).

Most equipment manufacturers provide recommended maintenance schedules for their products. Components that are exposed to water (e.g., drainage pans, coils, cooling towers, and humidifiers) require scrupulous maintenance to prevent microbiological growth and the entry of undesired microbiologicals or chemicals into the indoor airstream.

HVAC inspections: Be thorough in conducting these inspections. Items such as small exhaust fans may operate independently from the rest of the HVAC system and are often ignored during inspections. As equipment is added, removed, or replaced, document any changes in function, capacity, or operating schedule for future reference.

It may also be helpful to store equipment manuals and records of equipment operation and maintenance in the same location as records of occupant complaints for easy comparison if IAQ problems arise.

Building maintenance schedules: Try to schedule maintenance activities that interfere with HVAC operation or produce odors and emissions (e.g., painting, roofing operations) so that they occur when the building is unoccupied. Inform occupants when such activities are scheduled and, if possible, use local ventilation to ensure that dust and odors are confined to the work area.

Purchasing: Review the general information provided by MSDS and request information from suppliers about the chemical emissions of materials being considered for purchase.

Preventive maintenance management: Maintenance “indicators” are available to help facility staff determine when routine maintenance is required. For example, air filters are often neglected (sometimes due to reasons such as difficult access) and fail to receive maintenance at proper intervals.

Computerized systems are available that can prompt your staff to carry out maintenance activities at the proper intervals. Some of these programs can be connected to building equipment so that a signal is transmitted to your staff if a piece of equipment malfunctions. Individual areas can be monitored for temperature, air movement, humidity, and carbon dioxide, and new sensors are constantly entering the market. These sensors can be programmed to record data and to control multiple elements of the HVAC system.

Housekeeping

Indoor air quality complaints can arise from inadequate housekeeping that fails to remove dust and other dirt. On the other hand, cleaning materials themselves produce odors and may emit a variety of chemicals.

As they work throughout your building, cleaning staff or contractors may be the first to recognize and respond to potential IAQ problems. Educate them about topics such as the following:

Cleaning schedules: Consider how cleaning activities are scheduled. Managers may want to schedule the use of some cleaning agents that introduce strong odors or contaminants during unoccupied periods. However, make sure that fumes from cleaning products are eliminated before air handling systems switch to their “unoccupied” cycles.

Purchasing: Become more familiar with the chemicals in cleaning and maintenance products and their potential toxicity.

Select the safest available materials that can achieve your purpose. Review the information provided by product labels and Material Safety Data Sheets. Request information from suppliers about the chemical emissions of products being considered for purchase. Material handling and storage: Review the use of cleaning materials to ensure proper use and storage.

Trash disposal: Follow proper trash disposal procedures. If there is a restaurant in the building, require daily pick-up of perishable refuse. Ensure that the containers are covered, pest control is effective, and that the trash collection area is cleaned at least daily.

Shipping and receiving areas can create indoor air quality problems regardless of the types of materials being handled. Vehicle exhaust fumes can be minimized by prohibiting idling at the loading dock.

This is particularly important if the loading dock is located upwind of outdoor air intake vents. You can also reduce drafts and pollutant entry by pressurizing interior spaces (e.g., corridors) and by keeping doors closed when they are not in use.

Preventive Maintenance

An HVAC system requires adequate preventive maintenance (PM) and prompt attention to repairs in order to operate correctly and provide suitable comfort conditions and good indoor air quality. The HVAC system operator(s) must have an adequate understanding of the overall system design, its intended function, and its limitations.

The preventive maintenance program must be properly budgeted and implemented, not merely planned on paper. A well-implemented PM plan will improve the functioning of the mechanical systems and usually save money when evaluated on a lifecycle basis. However, in some buildings, because of budgetary constraints, maintenance is put off until breakdowns occur or complaints arise, following the “if it isn’t broken, don’t fix it” philosophy.

This type of program represents a false economy and often increases the eventual cost of repairs. Poor filter maintenance is a common example of this phenomenon.

Filters that are not changed regularly can become a bed for fungal growth, sometimes allowing particles or microorganisms to be distributed within the building. When filters become clogged, the fans use more energy to operate and move less air. If the filters are an inexpensive, low-efficiency type that becomes clogged and then “blows out,” the coils then accumulate dirt, causing another increase in energy consumption.

Poor air filter efficiency and poor maintenance may cause dirt to build up in ducts and become contaminated with molds, possibly requiring an expensive duct cleaning operation.

General elements of a PM plan include:

• Periodic inspection, cleaning, and service as warranted;

• Adjustment and calibration of control system components;

• Maintenance equipment and replacement parts that are of good quality and properly selected for the intended function.

Critical HVAC system components that require PM in order to maintain comfort and deliver adequate ventilation air include:

• Outdoor air intake opening;

• Damper controls;

• Air filters;

• Drip pans;

• Cooling and heating coils;

• Fan belts;

• Humidification equipment and controls;

• Distribution systems;

• Exhaust fans. FSM