Project Title:

Thermal Comfort in Naturally Ventilated Buildings

Natural ventilation for energy savings in California commercial buildings.

Status (updated 6/7/2012): Ongoing

Funding sources: California Energy Commission PIER


Project Objective

The goal of this study is to establish the ranges of indoor environmental conditions that can be comfortable in a naturally ventilated (NV) office building using operable windows and within-room fans. We also hope to better understand the physical charateristics creating the NV environment, and the role of occupant behavior.

Significance to Industry

For many years, almost all new commercial buildings have been air conditioned, mechanically ventilated, and filtered because the private sector has believed that these actions are necessary to maintain acceptable indoor environmental quality, despite the high energy costs. The market will not substantially adopt energy-efficient natural ventilation until we can provide the technical guidance and tools to assure that acceptable indoor environmental quality can be maintained an appropriate percentage of time. Providing such evidence and technical approaches to the market place is the focus of this project.

Research Approach

Two major tasks are included in this study:

(1) Monitor the environmental conditions in a naturally ventilated (NV) office, located in Alameda, California, in detail and survey occupants’ satisfaction of the office over a year. We will be measuring various indoor and outdoor parameters, including: air temperature, outdoor wind velocity, fan and heater usage, window opening behavior, and particle levels.

(2) Conduct CBE's Occupant Indoor Environmental Quality Survey in a few NV buildings and compare the results with the entire CBE database (more than 60,000 respondents in 600 buildings, which include HVAC, NV, and mixed mode buildings).

The research team will compile and analyze this data to draw conclusions that may provide guidance to building and system designers working on low-energy NV solutions.

Collaborators on this project include CPP, Arup, Cambridge University, UC San Diego, and the Environmental Energy Technologies Division at Lawrence Berkeley National Laboratory.

InteriorInterior of open office space with ceiling fans.

fisheyeResearchers are using fisheye photographs to document occupants' use of windows and blinds.