SVACH, short for Smart Ventilation for Advanced California Homes, is an ongoing LBL research project. The objectives of SVACH are these.
Objective 1. Revise IAQ Metrics
LBL will help the building industry revise indoor air quality (IAQ) metrics, reduce ventilation rates, and reduce concentrations of key contaminants, minimize energy use, and reduce peak demand. California needs new IAQ metrics to guarantee healthy indoor air for different ventilation approaches. These metrics must apply to zero-net-energy (ZNE) homes. ZNE homes are more air-tight and use smaller heating, ventilation, and air-conditioning (HVAC) systems than current California homes. Pollutant-exposure metrics will consider contaminants of concern (COCs) when homes are unoccupied.
This LBNL SVACH research project is essential to provide the information required by the California Energy Commission (CEC) and other policy makers to evaluate different options for future ventilation standards, particularly those related to ZNE homes. Neither the building industry nor the utilities would carry out this public-benefit work. Successful completion of SVACH should encourage new and improved public-benefit technologies.
Objective 2: Demonstrate that smart ventilation can provide acceptable IAQ in ZNE homes.
Smart ventilation will control ventilation airflow and air filtration to provide occupants with good IAQ at minimal energy-related cost.
Most California homes now use continuous ventilation and assume that these homes are single, well-mixed zones, which simplifies ventilation system design. This simple ventilation strategy meets minimum ASHRAE Standard 62.2 requirements. However, because of their small heating and cooling loads, ZNE homes often don’t have central ducted forced air heating and cooling systems to mix the air. ZNE homes often have separate zonal systems for heating and cooling and for ventilation. ZNE homes are airtight, so IAQ throughout the home depends on the distributed airflow of mechanical ventilation.
Objective 3: Determine how best to design ventilation systems for ZNE homes.
Improving envelope air-tightness to reduce air leakage and thus reduce HVAC energy use is an important energy-efficiency strategy for California. Research funded by the California Energy Commission (CEC) showed the necessity to understand IAQ before establishing aggressive air-tightening standards. IAQ standards now promote healthy indoor air while saving energy. The data from CEC research provides invaluable input for SVACH. Recognizing the importance of ventilation for maintaining good IAQ, the State building code requires installation of an ASHRAE 62.2-compliant ventilation system.
Advancements in smart ventilation extend our methods beyond existing smart-ventilation methods to add occupancy and contaminant sensing. New controls will minimize ventilation airflow when ventilation isn’t needed. Occupancy sensors could allow the ventilation system to minimize airflows when a home is unoccupied. Contaminant sensors could adjust airflows to keep contaminants below a pre-selected level based on health requirements.
Objective 4: Technology transfer
This project’s key technology-transfer objective is to get valuable information into the hands of stakeholders who can implement the recommendations. Those stakeholders include regulators, utilities, home builders, ventilation-equipment manufacturers, and those who train and educate workers. LBNL will use a variety of technology-transfer approaches to provide the information to different stakeholders. LBNL’s state-of-the-art review and this website are our main conduits for technology transfer.