Ventilation Solutions for Energy Efficient California Schools: Improving Indoor Air Quality through Advanced, High Performance HVAC

Evaluating Indoor Air Quality Impacts of High-Efficiency Retrofit HVAC Systems in California Schools

Regents of the University of California, Davis


Davis, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

The project is completed. In phase 1, the researchers collected indoor air quality (IAQ) monitoring, ventilation, and energy usage data from 104 classrooms in 11 schools using current HVAC systems. Researchers discovered high CO2 levels in some classrooms, suggesting poor ventilation, and worked with the CEC to provide schools tools and information to install, commission, and maintain systems appropriately. In phase 2, researchers installed and commissioned 2 next-generation HVAC systems on 2 schools. In phase 3, the team conducted simulation for schools built in 1998 and 2008. Results show energy savings and IAQ improvements from new HVAC systems. Use of high efficiency air filters significantly decreased PM2.5 levels without significant increase in ventilation energy. Researchers worked with manufacturers to fix issues with the new systems such as additional standby power consumption.

The Issue

Research indicates that many California classrooms are under-ventilated relative to rates specified in Title 24 and ASHRAE 62.1. Simply increasing outdoor air ventilation rates in classrooms has pitfalls: it will increase energy use, and it can have the unintended negative consequence of increasing student exposures to outdoor air pollutants. As California looks ahead to achieving 50% energy use reductions in existing and future ZNE schools, there is a need to demonstrate ventilation approaches that are substantially more energy efficient than current, minimally code-compliant systems.

Project Innovation

The project includes three phases: 1) conduct energy and indoor air quality measurements in California classrooms to establish baseline data; 2) identify and install new, highly efficient HVAC technologies at selected schools and collect data from these schools; 3) conduct energy consumption and indoor air quality simulations based on information collected from previous two phases in representative climate zones in California, and compare simulation results with field data. The identified technologies in this study include heat recovery ventilators, air economizers, demand control ventilation, displacement ventilation, high-performance filtration, and learning thermostats. These are advancements that are over and above the technologies typically used in California schools, and can greatly improve the energy efficiency of providing heating, cooling, and ventilation in classrooms.

Project Benefits

The project provides information on indoor air quality and energy usage in classrooms with current HVAC systems throughout different parts of California. It demonstrated the next generation HVAC system retrofits with regards to energy efficiency and indoor air quality performance. The results enable energy savings without impacting indoor air quality in classrooms. The study is the first large field study to examine the energy efficiency and indoor air quality impacts after recent energy retrofits.

Lower Costs


By field testing several HVAC technologies that provide significant savings over existing systems, this project will result in energy savings from improved equipment performance and lower costs associated with delivering thermal

Key Project Members

Project Member

Curtis Harrington



Lawrence Berkeley National Laboratory


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