Investigator: Ilka
Berrios
(email: itberrio@syr.edu)
Faculty Advisor: Dr. J. Zhang
Department of Mechanical and Aerospace Engineering
This study characterizes indoor
emission sources that are close to the occupants in a partitioned office
environment. These sources include personal computers, printers, copiers,
carpets and an office workstation, which consists of desk, chair, cabinet, and
partitions. The objectives of this study
are to identify the major pollutant sources typical of a partitioned office
environment, measure their emission characteristics, and determine their impact
on the occupant’s exposure. In the study, a typical office workstation was
first defined, and potential emitters identified. Depending on the size and
type of the sources, mid (5 m3) and full-scale (22.1 and 54.37 m3)
stainless steed chambers were used for characterize the emissions from
individual sources. These sources are divided in two categories: “active” and “passive”
sources. Active sources are the ones that emit heat as well as pollutants and
they depend on the operation modes, these sources include personal computers,
printers and copiers. Passive sources include building materials and furniture;
these sources are less complicated than the active sources.
First three different desktop computers were tested; one of them with a thin-film transistor (TFT) monitor and the other two computers include a cathode-ray tube monitor (CRT). After these tests, was found that the emission rates for the computers were about 10 to 120 times higher when the computers were on than off depending on the VOC. In addition, was found that the computers with CRT monitors have slightly higher emissions that the ones with TFT monitor. The second sources tested were three printers and a copier. The first two printers were laser jet and the third one inkjet. From these tests was found that the emissions rates from printers and copiers during the off and idle periods are negligible compared with the high emissions during the operating and post-operating period.
For the passive sources, each component of a workstation system was tested individually. The tested components were: chairs, carpet, drawer, table surface and partitions (panels). From these tests, it was found that the furniture components decayed very slowly after the first few days, exhibiting an internal diffusion controlled process. After every component was tested, a complete workstation, including all the individual sources, was tested. The test results are compared to predictions of a simulation model that accounts for the effects of emission and sorption characteristics of individual components of the workstation, as well as ventilation rate.
Some simulations were conducted using the MEDB-IAQ (Material Emission Database – Indoor Air Quality) program to assess the impact of the office equipment and furniture, the amount of materials used and the ventilation rates on the VOC concentration in an office.