Capitol Improvements

12/04/2002 |

Indoor Air Quality Takes Center Stage

In 2000, California Gov. Gray Davis signed an executive order to support sustainable building practices including, among other priorities, enhancing indoor air quality in the construction and maintenance of government offices. Next year, the State of California will complete work on the Capitol East End Area Complex, a new multi-unit facility that will consolidate the headquarters of the state departments of education and health services. The Sacramento project embodies many sustainable building principles and particularly addresses indoor air quality (IAQ) issues.

The overall goal toward improving IAQ in the facility will be reached by reducing potentially harmful chemical emissions within the building and by providing adequate ventilation to dissipate any odor and chemical emissions within. To accomplish this, the facility will incorporate a variety of techniques.

According to the State of California, IAQ will be regulated for carbon dioxide levels with continuous monitoring by the facility management and control system, and the levels will be automatically adjusted to maximize the benefit of fresh air while minimizing energy consumption. Fan systems will operate continuously during building occupancy with limited close-off terminal units to assure introduction of minimum levels of outdoor air. In addition, building supply air systems will employ high-efficiency filtration to control particulates in the air stream, and excess capacity in the mechanical system will allow for future increases in the volume of outdoor air. Finally, the facility has chosen materials and finishes with low or zero volatile organic compounds (VOCs), where possible.

While all the design and active measures employed by the State and its project team to ensure improved indoor air quality at the Capitol East End Area Complex are exemplary, the final priority is one of great importance: Materials and finishes that complete a building should be held to the same high standards of IAQ as the HVAC system or air quality control system. Today, there is an increasing responsibility on the part of building products manufacturers to adhere to sustainable building principles that address indoor air quality issues and the environment in general.

Industry experts often refer to the tightening of the building envelope in modern construction. By definition, the building envelope refers to the thermal barrier between the indoor and outdoor environment. Building environment elements are the key determinants of a building’s energy requirements, given the climate where a structure is located. While the tightening of that envelope unquestionably results in increased energy efficiency and reduced energy consumption, there may be unintended consequences from reducing airflow between the indoor and outdoor environments.

Chief among concerns is the recirculation of trapped VOCs in the indoor air environment. While the Capitol East End Area Complex is implementing outstanding efforts to actively control the circulation of VOCs, the simplest way to eliminate those concerns is to reduce or eliminate the number of VOCs introduced into the building envelope in the first place. Selecting finishing materials designed to support overall indoor air quality is therefore paramount to preventing the initial introduction of such compounds, and may be a critical step toward improving indoor air quality.

Jo Anne Cambruzzi is the business manager of commercial markets for the building insulation division at Johns Manville (, headquartered in Denver.

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