Cyert Hall Air Quality
    Committee Progress Report     

    August, 1997

    Background

    The Cyert Hall Indoor Air Quality (CYH IAQ) Committee was formed in 1993 to review and resolve environmental problems that have occurred in Cyert Hall since the building's general occupation in 1985.

    The committee consists of:

    • Pat Keating, CFO and Vice President for Business
    • Alex Hills, CIO and Vice Provost for Computing Services
    • Ron Carter, Assistant Vice President for Facilities Management Services
    • Chuck Bartel, Director of Operations, Computing Services
    • Ken Burner, Facility Coordinator for Computing Services
    • Other members of FMS and Computing Services attend the bi-weekly meetings on an as-needed basis. We would like to especially acknowledge the regular contributions of John Mier, HVAC Engineer and Project Manager.

    Areas of Work

    When the committee began, it was facing a number of indoor air quality issues in Cyert Hall. Some of the major occupant concerns at this time were:
    • Intermittent fallout of black particles from ceiling vents in several offices and work areas.
    • Complaints of exhaust fumes and occupant concerns about carbon monoxide in A-level work areas.
    • Humidity fluctuations (low in winter, high in summer).
    • Occupant health complaints similar to Sick Building Syndrome (SBS).
    • Complaints of cigarette smoke infiltrating the building.
    • Poor communications between occupants and management.
    • What follows is an update on the committee's progress in addressing these concerns.

    Black Particles

    Black particles have been the topic of many of the IAQ Committee's meetings. So far, we know the following about them:
    • They are non-toxic and not hazardous to your health (verified by two independent, non-CMU lab studies).
    • They are composed mostly of soot.
    • They are unrelated to the cleanliness of the air handling system (filters, ductwork, machinery).
    • They are not unique to Cyert Hall and have been observed in other CMU buildings. They occur in varying degrees in many air handling systems.
    • They appear to be produced in Cyert Hall by aggregation of micro-fine materials inside Moduline ceiling air diffusers manufactured by Carrier Corp., original equipment in this building.

    Solutions to Date

    Black Particles can be temporarily eliminated by cleaning the interiors of the Moduline diffusers. This is a fairly labor-intensive process and the effect is short-lived -- on the order of 1-3 months. The replacement of filters (or the use of higher grade filters) seems to make little difference in reducing the generation of black particles.

    It appears that black particles can be permanently eliminated by replacing the Moduline diffuser with a slot diffuser coupled with a separate VAV (Variable Air Volume) air mixing chamber.

    The current procedure is to have Cyert Hall occupants report black particle sightings whenever they occur. When there are 2 or more reports for an office within a week, a request is made to FMS to have the Moduline diffuser replaced with the new type. This retrofit takes 4-6 weeks to be completed.

    To date 25 Moduline units have been replaced with the new style diffusers in the following areas:

    • A level: A66, A68, A70, A74
    • 1st floor: 101, 103, 104, 105, 108, 119, 120, 121, 123, 125, 127, 131,132, 134, 135, 173, 181
    • 2nd floor: 214, 223, 263, 286
    As a result, there have been no significant reports of black particles in the areas which have these new installations. Also, new reports of fallout in other offices or work areas have decreased drammatically since this retrofit effort has been implemented.

    This process is now considered to be a routine one and the matter will be re-addressed by the committee if the current procedure, described above, fails to be a long-term solution to the problem.

    Humidity

    High humidity has been a historical problem in some parts of CYH, but over the past two cooling seasons, both regular humidity measurements and the absence of occupant complaints indicate that this has not been a major problem in the recent past.

    The committee has asked that potential solutions to high-humidity problems be evaluated by FMS staff. This evaluation was completed and the only realistic solution involves a retrofit of existing air-handlers. The costs of this program were considered too great considering both the present limited scope of the immediate problem and a long-term plan to replace the HVAC system as part of a move from glycol cooling to chilled water cooling during the next several years. The committee decided not allocate funds to control high building humidity at this time.

    Low humidity has also been a problem. Occupants have complained about the symptoms of low humidity (excessive static electricity, dry nose & throat, dry skin, etc.). FMS was asked to study the problem and propose solutions.

    The study found that there have been humidity reading as low as 6% during the heating season. These humidity levels are well below the 30% level recommended by the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE).

    Solutions to Date

    FMS installed a prototype humidifier in one of the air handlers in March, 1996. Initial results were that this unit can maintain 30% relative humidity during the driest times of the year. The committee approved a plan for FMS to install these units in all of the building air handlers. This project was completed during the 96/97 heating season.[1]

    In addition to the installation, FMS agreed to periodically monitor the humidity levels during future heating seasons.
     

    Air Circulation

    Complaints of exhaust fumes and concern about carbon monoxide levels by occupants of the A-level work areas, complaints regarding staff illness related to "sick building syndrome", complaints about stuffy or stale air and complaints regarding cigarette smoke infiltrating the building all fall under the area of air circulation.

    Regarding stuffy or stale air, the basic problem is that the building HVAC design allows only for the variable flow of cold air. In order to warm a space, the system reduces the supply of cold air to an office or work area. Human body heat, radiant energy from the sun and heat from electrical equipment provide "free" heating in the absence of cool air. However, since cool air is also the only supply of fresh air to the space, the usual result of such warming is a stuffy work area. This condition has been shown to correlate positively with occupant complaints such as sore or scratchy throats, dizziness, headaches, inability to concentrate, nausea, etc.

    Solutions to Date

    We have found that replacing the Moduline diffusers with an alternate system that is capable of reheating incoming air results in a space where temperature and fresh air can be controlled independently. This seems to have made an improvement in occupants' opinions of their work environments. We have installed this solution in 4 offices to date, CYH A-70, A66, A68 and 123.

    Although this seems to be a workable solution, it is a costly and inefficient one, requiring the installation of an electrical heating unit to heat the cooled air in each office.

    Because of the high operating costs, the committee is approving the installation of this solution on a case-by-case basis. We are currently devising a procedure that will better automate the reporting, verification and correction of this type of problem.

    Negative Air Pressure

    Regarding complaints about the infiltration of smoke, exhaust and other indoor pollutants, attempting to solve this has been an iterative process. Part of the problem is related to the indoor pressure of the building. In an ideal case, an HVAC system draws air both from the outside (through a designed scheme of ductwork and building vents) and the inside (though ducted air returns) of the building. A negatively pressured building is one where the HVAC system draws more outside air, in some cases from undesigned areas in the building, such as entrances, loading docks and windows. A way to compensate for negative pressure is to increase supply air through the building's HVAC system. This method pressurizes the interior space and resists the infiltration of outside contaminants.

    In Cyert Hall we have both positive and negative pressure areas. Most of the floors are positively pressured, but the B-level is not. Compounding this problem is the location of both the building loading dock and its proximity to the B-level air handler that supplies air to most of the A-level. When vehicles using the loading dock leave their engines running, exhaust fumes can be drawn in by the air handler and distributed throughout the building.

    Solutions to Date

    Very early in the process, we instituted a new loading dock operational procedure for Cyert Hall. This procedure involved the installation of carbon monoxide monitors/alarms and a garage door control system that establishes an effective air lock in the loading dock area. This has helped, but the procedures rely on self-policed compliance and there have been cases where the policy's effectiveness has failed.

    In late Fall 1996, FMS tested air pressure in various areas of the B-level and made modifications to the mechanical systems to compensate for the negative pressure effects. While these changes helped balance airflow throughout the areas, they have not solved the problem of overall negative pressure. FMS is currently implementing additional changes to the B-level that include: increasing the amount of air supplied to the mechanical equipment rooms, installing thresholds and door seals on problematic doors and closing return air dampers in B-25 and B-28. The area will be retested after these changes have been made and if these attempts fail, further measures, such as a loading dock exhaust system, will be considered.

    Regarding the infiltration of cigarette smoke into Cyert Hall, this appears to come mainly from people smoking directly outside of the building. The smoke comes in during the normal entrance and egress of people into Cyert Hall. This problem is further complicated by the recent installation of automatic door openers to accommodate physically challenged people entering and exiting the building. The use of the door openers negates the double-entry air lock system in place at the Forbes Ave. and Warner Hall lot entrances.

    The committee will evaluate possible solutions to this problem which can accommodate both the needs of the physically challenged and the needs of the other occupants of the building.

    Other Building Issues

    The committee has had several discussions about equipping external offices with operable windows. Although this can be done, and at a reasonable cost, it is the consensus of the committee that the current air handling systems in the building were not designed for and probably could not cope with the humidity, air circulation and temperature variables open windows would produce. We have decided not to do this at this time.

    Communications to the Occupants

    In the area of communications, early in the life of the CYH IAQ committee, there seemed to be more miscommunication than communication regarding the issue of Cyert Hall indoor air quality. First attempts involved surveying the occupants to understand the problem areas as they saw them. These surveys were followed up by a series of update memos from Bill Arms (then VP for Computing Services).

    Later, the minutes of these meetings were made public and are being posted as a regular practice on the org.acs.ucc-discuss bulletin board. In addition, a Cyert Hall website was created that provides some information on the HVAC distribution system.

    Although the publicly available minutes provide ongoing information to the occupants of CYH on the status and actions of the committee, the overall impact of the efforts over time can be lost in this media. This report is intended to fill that gap, and the goal is to provide periodic updates to this report on a yearly basis.

    ------------------------
    [1] Note that only interior air handlers were equipped with humidifiers during this project and that the relative humidity remained 30% or higher during the 1997-98 heating season.

    Time Line

    The following is a list of some historical milestones relating to Cyert Hall air quality improvement during the past several years. This is a list of key events and does not detail the significant testing, discussion and evaluation that led to them.
     
    Aug 1993 SE Technologies releases audit of CYH mechanical systems; makes specific recommendations for improvements.
    Oct 1993 CYH A-70 Environment Problem Solving Team formed.
    Jan 1994 RJ Lee reports on microscopic and spectrographic analysis of black particles.
    Feb 1994 Occupant survey reveals 80% dissatisfaction with building environment.
    Mar 1994 Administrative controls on loading dock operations implemented.
    Apr 1994 CYH A-70 Environment Problem Solving Team report released.
    Apr 1994 David Tollerud, Univ. of Pitt. Director of Occupational and Environmental Medicine, reports on non- health threatening nature of black particles.
    May 1994 Memo from VP Bill Arms updates occupants on black particle status.
    Jun 1994 Memo from EH&S Director Pete Collopy summarizes progress on IAQ issues.
    Sep 1994 Memo from VP Bill Arms updates occupants on progress toward reducing black particles.
    Dec 1994 HVAC retrofit completed in A-70. Airflow increased from 475 to 730 cfm.
    Feb 1995 Ethylene glycol replaces propylene glycol in building cooling system.
    Mar 1996 Humidifier installed on B-level Blazer air handler.
    Apr 1996 Flood & Sterling analysis reveals slight negative air pressure in B-level.
    Aug 1996 B-level areas re-balanced.
    Oct 1996 A70 occupant survey reveals 60% satisfaction level with air
    quality, health symptoms.
    Nov 1996 A70 supply air measured, found to be within spec for
    space/occupancy requirements.  FMS makes specific recommendations to A70 occupants for improving perceived air quality.
    Jan 1997 Main building entrances equipped with automatic doors for assisted access.
    Mar 1997 All air handlers equipped with humidifiers.
    July 1997 Modifications for positive air pressure in loading dock area completed.
    Aug 1997 IAQ Committee progress report released.

    <<<   Return to the Cyert Hall home page.