Interiors Backgrounder

The Big Picture

Indoor Environmental Quality strategies reduce potential liability for design team members (including building owners), increase the resale value of the building, and increase productivity of building occupants. In fact, case studies suggest that IEQ improvements can increase worker productivity by as much as 16%, resulting in rapid payback for IEQ capital investments.

IEQ strategies include issues related to indoor air quality such as increased ratios of filtered outside air, ventilation effectiveness, moisture management, and control of contaminants. Specifying materials that release fewer and less harmful contaminants is even better. Another strategy is to protect air handling systems during construction and perform a building flush-out prior to occupancy. To provide optimal air quality for building occupants over the lifetime of the building, automatic sensors and controls can be integrated with the HVAC system to adjust temperature, humidity, and the percentage of outside air introduced to occupied spaces.

Other IEQ issues to consider include daylighting and lighting quality, thermal comfort, acoustics, occupant control of building systems, and access to views. All of these issues have the potential to enhance the indoor environment and optimize interior spaces for building occupants.

The Context

Americans spend an average of 90% of their time indoors, where levels of pollutants may be two to five times — and occasionally more than 100 times — higher than outdoor levels, according to the U.S. Environmental Protection Agency. Major health disasters such as outbreaks of Legionnaires’ disease and sick building syndrome have heightened the awareness of indoor air quality for building owners and occupants. An increasing number of legal cases emphasize the need for optimal indoor environmental quality strategies.

Since IEQ is tied to worker productivity, it is natural to also see a relationship between IEQ and the learning environment. Schools primarily serve children, and because children’s bodies are still developing, they are more susceptible to certain contaminants that can exacerbate illnesses such as allergies and asthma. Allergies are responsible for 3.5 million lost U.S. workdays each year, at a cost of $639 million. An estimated 2 million school days are lost each year due to allergies, with an indirect cost reaching $4 billion. In 1999 the National Center for Educational Statistics for the Department of Education reported that approximately one in five U.S. public schools had unsatisfactory indoor air quality.

The healthcare industry is especially focused on IEQ and its effect on the healing environment. Design attributes such as color, texture, and daylighting are all considerations for maximizing IEQ in the healing environment, and in facilities that serve the aging population. These IEQ considerations related to aesthetics must be carefully balanced with considerations for avoiding cross contamination from a wide variety of sources. Some microbial contaminants can cause or exacerbate infections. The control of microbial contaminants is of greatest importance in areas that serve children, the elderly, and other immune-compromised populations.

Getting Down to Business

• The PNC Firstside Center, a banking facility in Pittsburgh, Penn., incorporates a hybrid local ventilation system that combines underfloor air distribution with a conventional VAV system. Air is introduced through floor diffusers at each workstation to deliver fresh air directly to building occupants. Natural air convection is used to create upward air movement in conditioned spaces and air is exhausted through ceiling vents. This ventilation strategy creates temperature stratification about six feet from the floor. The zone below the stratification is cool and provides a comfortable working environment for building occupants. The zone above the stratification acts as a reservoir for warmer air. This ventilation pattern provides optimal conditioned temperatures to building occupants, resulting in increased productivity while decreasing HVAC operating costs.
  
• The University of California at Santa Barbara’s Donald Bren School of Environmental Science and Management houses campus facilities including research and teaching laboratories, and offices. The ventilation system incorporates operable windows for flow-through ventilation that can be controlled by occupants. The operable windows interface with the heating elements and the elements are automatically turned off when the windows are open. The lighting plan includes occupant-controlled energy-efficient fixtures.
  
• The Greater Pittsburgh Community Food Bank houses distribution, warehouse, and processing facilities and is designed to utilize site resources and be a positive workspace for building occupants. An indoor air quality management plan was adopted to avoid air contamination in the building during construction activities. VOCs were controlled through source reduction and housekeeping efforts. Particulate contamination was reduced by physically separating the HVAC system from construction activities and by cleaning the HVAC system before occupancy. Combustion was controlled by limiting combustion activities on site and locating combustion sources away from air supply intakes. Finally, cleaning agents were specified to contain no chlorine or ammonia.
• The NW Federal Credit Union building is a commercial office facility that houses a financial institution. The building was designed to harvest site resources and create a positive work atmosphere for building occupants as well as showcase environmental measures for banking patrons. The building is oriented on an east-west axis, and the floor plates are elongated to maximize solar access into the building interiors. Exterior shading devices and interior light shelves direct sunlight into the space without causing undesirable glare. Window glazing was selected to reduce glare on computer monitors while allowing natural light into the occupied spaces. Finally, interior finish colors were chosen to bounce light to the deep interior spaces, creating a vibrant and positive workspace.

Key Players

• Designers and architects are quickly gaining expertise in designing for optimal IEQ performance.
  
• Builders also are becoming increasingly familiar with IEQ issues, as more clients seek more environmentally responsible materials.
  
• Retailers of environmental products are developing and selling products that are easier on the environment than traditional products. From low-toxic paints to recycled carpet, most building materials retailers sell products through catalogs, online, and in select retail outlets.

The Upside

Good IEQ reduces potential liability for architects, builders, owners, building operators, and occupants, as well as increases the value and marketability of a building. Optimal IEQ performance in buildings also results in improved occupant comfort, well-being, and productivity.

Personnel costs are a significant percentage of operating costs, much greater than energy or maintenance costs, and, thus, actions that affect employee attendance and productivity are significant. The projected productivity gains that may be obtained by providing better indoor environments is estimated to be very large. For the U.S. the estimated potential annual savings plus productivity gains range from $30 billion to $170 billion.

Case studies suggest that IEQ improvements can increase worker productivity by as much as 16%, resulting in rapid payback for IEQ capital investments. Another study shows that the financial benefits of improving office climates can be eight to 17 times larger than the costs of making those improvements. Time off due to illness can be cut by as much as 30% if workers simply have control over their office air.

Reality Check

Some IEQ strategies may involve significant initial costs. Increased ventilation rates may result in greater annual energy costs. However, the additional costs can usually be offset by improved occupant productivity and lower absentee rates. Natural ventilation strategies are typically much less expensive to construct and operate than mechanical ventilation strategies, but require an appropriate climate and more comprehensive design analysis.

Action Plan

Here are some basic tips for designing and maintaining building systems that promote optimal IEQ performance.

• Evaluate the project site prior to acquisition to avoid choosing a site with potential IEQ problems.
  
• Establish air quality standards early in the design process, and clearly state these design criteria in plans and specifications.
  
• Avoid over-design and under-design of the ventilation system and anticipate future retrofits.
  
• Designing the ventilation system to take maximum advantage of regional climate characteristics can help cut down on energy costs and increase ventilation options.
  
• During construction and building fit-out, protect building materials from moisture and specify materials and furnishings that do not release harmful or irritating chemicals, such as volatile organic compounds (VOCs) from paints and solvents, to reduce the detrimental effects these substances have on air quality.
  
• Building construction processes invariably include activities that contaminate the building during construction. A ventilation flush-out prior to occupancy will help reduce such contamination.
  
• Whenever possible, select low-VOC alternatives to conventional interior design materials such as adhesives, paints and coatings, carpet systems, composite wood, and agrifiber products.
  
• Store all housekeeping products and chemicals in areas that are adequate, secure, and isolated from the activities of building occupants.
  
• Provide individual interior environmental controls such as thermostats, vents, operable windows, and shading devices.
  
• Upon project completion, include in the building commissioning report operational testing of HVAC systems. Implement an operations and maintenance plan to maintain optimal IEQ performance.

Leads

• International Council on Ventilation Hygiene
  
  Promotes global awareness of duct cleaning and indoor air quality.

• EPA Indoor Air Quality Program
  
  Provides information on indoor air pollutants.

• Choose Green Report: Architectural Paints
  
  Presents selection criteria for environmentally preferable brands of interior and exterior paint — and lists 96 products from 17 manufacturers.

• Choose Green Report: Floor Coverings
  
  Hands-on help for choosing carpet follows a thought-provoking lecture on indoor air quality.

• Environmentally Responsible Carpet Choices
  
  No-frills online report is a must-read for anyone purchasing carpet.

• Fact Sheet: Ventilation and Air Quality in Offices
  
  Discover where indoor air pollution comes from, how poor air quality affects human health — and what you can do about it.

• Commercial Building Ventilation and Indoor Environmental Quality
  
  Clearinghouse for the Berkeley lab’s research on indoor air pollutants and their effects on health and work productivity — and the environmental technologies available to remedy them.

• Heating, Ventilation, and Air Conditioning Energy Efficiency
  
  Cut your HVAC operating costs with the tips you’ll find on this Web site.

• Building Air Quality: A Guide for Building Owners and Facility Managers
  
  All the basics on preventing, identifying, and correcting indoor-air-quality problems.

• Greenguard
  
  For better indoor air quality, search this site to find office products and building materials certified by Greenguard Environmental Institute as non-toxic and generating low emissions.

• Building Air Quality Action Plan
  
  Follow this eight-step plan to clean, healthy indoor air.

The Bottom Line

Prevention of IEQ problems is generally much less expensive than cleaning up after these problems occur. Initial investment in designing and maintaining sound IEQ systems is well worth the cost, increasing worker productivity and mitigating environmental problems associated with building construction and function.

Finally, IEQ issues do not stem from one source. The issue is multi-faceted, and can therefore only be addressed through a systems approach, focused on the whole building and all its systems and components. One system cannot exist independently of the other. They must all be in place to maximize indoor environmental quality.

Special thanks to Valerie Bennett, executive director of Envirosense Consortium, Inc., for her contribution to this article.