A Field Study of PEM (Personal Environmental Module) Performance in Bank of America's San Francisco Office Buildings
This report describes the results of a field study performed by UC Berkeley in collaboration with Bank of America Corporate Real Estate and Johnson Controls World Services. The purpose of the study was to assess the impact of installing Personal Environmental Modules (PEMs) at 42 selected workstations within three Bank of America office buildings in San Francisco. The PEM is an example of a relatively new approach to space conditioning and control in which individuals are given the ability to control critical environmental conditions within their local work area (e.g., workstation). Each office worker can adjust air flow, temperature, lighting, and acoustic characteristics to maintain their own personal comfort levels. By improving employee satisfaction and well-being, it is anticipated that the installation of a PEM system could lead to increased worker productivity and effectiveness.
In this study, field measurements were performed both before and after the PEM installation to evaluate the impact of the PEM system on occupant satisfaction and thermal comfort, as well as the thermal environments within the office buildings. Within each building two distinct groups, each having approximately the same number of subjects, were selected to participate in the study: (1) PEM group, consisting of workers who occupied workstations in which PEM units were to be installed; and (2) control group, defined to be a group of workers in the same building having similar work conditions to the PEM group, but who would not be receiving PEMs in their workstations. By collecting and comparing measurement data from these two groups, it was anticipated that the impact of installing the PEMs could be most meaningfully evaluated.
The measurement methods used in this field study included (1) occupant surveys, (2) short-term physical measurements of environmental conditions at individual workstations, (3) long-term trend measurements of temperature, humidity, and air quality conditions, and (4) network-based monitoring of occupant use patterns of the PEM desktop controls. The first baseline field measurements were made in March 1996. The 42 PEM units were installed in the three buildings during the first two weeks of April. The follow-up field measurements were completed in July, three months after the PEM installation. During the follow-up field tests, measurements were repeated under three different room temperature setpoint conditions to investigate the occupants’ ability to use the PEMs to control their local environment to satisfy their personal preferences above and below the typical ambient setpoint temperatures.