Too hot, too cold, or just right: Green Seed project evaluates indoor thermal comfort

In 2009, the UW Climate Action plan was created to establish a climate-neutral campus. Although smart meters make measurements of power usage in University buildings available to administrators and researchers, the related indoor environmental quality had not been evaluated.

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Data collecting station in the Student Legal Services office.

CEE faculty Amy Kim and Dorothy Reed, project co-investigators, along with ISE graduate research assistant Stanley Wang and Yiming Liu, CEE engineering technician, examined the thermal comfort of the LEED-certified Gold Husky Union Building in the Green Seed Fund project Indoor Environment Quality Assessment. Measuring indoor environmental quality through both occupant comfort surveys and in-situ measurements of temperature and humidity, two measurement stations were installed in a commercial kitchen environment and the one in a small office.

The office occupants were overall satisfied with the thermal comfort of the building. Nevertheless, slightly lower and higher room temperatures were observed during early mornings and late afternoons in the summer. The free-cooling strategy, night ventilation, was successful in reducing the indoor temperature to a comfortable level in the morning. However, without a mechanical air-conditioning system, the rise in outdoor temperature during the summer afternoons, in combination with the higher occupancy rate, increased the temperature in the office spaces to exceed the 80 percent ASHRAE acceptability limits (which defines the ranges of acceptable indoor environmental conditions to achieve thermal comfort). The survey showed that occupants found the lower temperature in the morning acceptable but were bothered by the higher temperature in the afternoons.

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Data collecting station at Firecracker in the HUB.

Objective measurement of the two kitchen areas, cooking and dishwashing, showed frequent exceedance of 80 percent ASHRAE acceptability limits as defined in ASHRAE 55-2013 Section 5.4. Most of the kitchen employees reported complaints about the indoor operable temperature, including low air movement that caused discomfort with high temperature and sweating. An overwhelming number of respondents, almost three-fourths, indicated that most of the time they felt uncomfortable working in the kitchen. They suggested adding additional mechanical cooling systems.

The results presented here are preliminary and data collection continues through 2015.

 

Through Green Seed Fund grants, the UW seeks to engage faculty, students, and staff in opportunities that advance sustainable research while contributing to campus sustainability goals. Successful proposals use the campus as a living, learning laboratory and help the UW find solutions to the most pressing environmental issues.

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