Thermal and acoustic comfort in workplaces
It is hard to focus on work in an office which is too cold, too warm or noisy. Thermal and acoustic comfort is essential for a high-quality indoor environment where occupants feel most productive and that also has a positive impact on health. Lack of comfort can cause stress among building occupants and negatively affect their work performance.
GBCI India and Saint Gobain Research India recently released a joint study, Healthy Workplaces for Healthier People, that evaluates the health performance of office buildings in India. The study evaluated 30 offices located in nine cities of India. Building data collected from project teams and professionals who work at the buildings, along with onsite measurements and inspection; and occupant feedback collected through online surveys were all analysed to determine whether the buildings were delivering healthy and comfortable spaces. Important parameters such as indoor air quality, lighting, access to outdoor views, thermal comfort, and acoustics, that define workspace quality, were evaluated.
Thermal comfort in the workplaces
The study found that thermal comfort conditions were as per the standard in 75% of the office spaces and 62% of the surveyed occupants were satisfied with their thermal environment.
However, it was observed that very few buildings provided complete control to occupants to modify thermal settings. In most buildings, the thermal conditions were controlled centrally by the building management system. Only the meeting rooms had thermostats whose setting could be modified by the occupants, however, in open office spaces, the facilities team controlled the thermostat temperature set points. In spaces where occupants could manage the set points, they could only do so partially. This led to overcooled or undercooled spaces and resulted in occupant discomfort.
Spaces cooler than what occupants prefer
Study findings showed that 56% of the spaces operated on the cooler side of the comfort zone. However, analysis of occupants’ perception of their thermal environment, showed that comfort perception improves when buildings are on the warmer side of sensation. Putting it simply, while the occupants preferred slightly warmer spaces, many spaces were overcooled.
This indicates that operating buildings on the warmer side of the comfort zone will not only keep occupants happy but also result in significant energy savings.
All offices performed well in reducing the noise from outdoor sources, and 77% of the offices had the reverberation time as per the recommended level. However, interior background noise levels, primarily due to HVAC equipment, were higher than the standard threshold in 73% of the spaces. In many spaces, it was observed that the HVAC equipment was ceiling-suspended in open office areas where people work, or the equipment room was near the work area without proper noise isolation. The proximity of HVAC equipment, inadequate noise isolation for the equipment room and exposed ceiling with open ductwork were the main reasons for high interior noise levels.
57% of the occupants reported satisfaction with the acoustics conditions and those dissatisfied with their space acoustics reported “no acoustic privacy,” and “loud noise” as the main reasons for dissatisfaction.
Role of interior finishes in acoustic comfort
We found that ceilings with acoustic tiles performed best in optimizing the echo or reverberation time compared to other types of finishes. Offices with internal partitions made from drywall exhibited lower measured background noise than those with no partitions or partitions made from other materials like medium density fiberboard (MDF) or other hard surface partitions.
Read the Healthy Workplaces for Healthier People study to get more information on health performance of workplaces in India, and to learn strategies to ensure occupant health is prioritized in these spaces.