This project involves measuring the indoor environmental conditions in classrooms at local school districts; specifically 3
grade math and English classrooms are targeted. Two different types of measurement surveys are conducted : (1) unoccupied measurements and (2) two-day logging measurements within the occupied classrooms. The unoccupied measurements take place after student dismissal and primarily serve to obtain characteristics of the classrooms that are not expected to change due to occupancy. For two-day logging measurements, research team members arrive before school to set up the test kit in the classroom. These kits stay in the classrooms for two school days and are then picked up at the end of the second day. Equipment in the kits capture information about the environmental conditions in the occupied classrooms, such as temperature, sound level, and lighting levels; no personal or identifiable information is gathered, though. Both types of measurements take place once every season. Please explore the sections below to learn more about the environmental conditions being surveyed.
Thermal
For thermal conditions, both air temperature and relative humidity are monitored continuously in the two-day logging kits, while the air velocity is measured during the unoccupied conditions to identify any potential draft/stagnation issues that may lead to thermal discomfort.
Indoor Air Quality (IAQ)
The following parameters are monitored to evaluate the indoor air quality: airborne particles/the particle number concentration, carbon dioxide (CO2), ventilation rate, nitrogen dioxide (NO2), total volatile organic compounds (TVOCs), and formaldehyde.
Airborne particles, CO2, ventilation rate, and formaldehyde are measured continuously in the two-day logging kits, while NO2 and TVOCs are measured during the unoccupied conditions.
Lighting
The indoor lighting environment is defined by many variables, such as illuminance and luminance levels, color characteristics of light sources (color rendering index, correlated color temperature), contrast, glare index, and daylighting.
Illuminance measurements and High Dynamic Range Images are used to calibrate models of the classrooms to get a more complete picture of the lighting conditions in each classroom. Illuminance measurements are made continuously in the two-day logging kits, while spot-checks and High Dynamic Range Images are taken during the unoccupied conditions.
Acoustics
Sound level meters are used to monitor the background noise levels of each classroom. The two loudest locations within the listener areas are carefully selected and measured by logging in five-minute intervals continuously for two days. The mechanical system operating conditions and exterior noise proximities are also identified. Using an integrated impulse response method, reverberation time measurements are conducted in the unoccupied conditions.