Simulation and Analysis

This activity combines direct analysis of the field data with simulations using LBNL's REGCAP model. Our goal is to evaluate how to provide adequate ventilation in homes while reducing infiltration beyond the 2008 Title 24 Building Standard to provide acceptable indoor air quality (IAQ).

Using data that are gathered from occupant survey and field measurements, the objectives of this simulation task are as follows:

  • Identify what types of mechanical ventilation devices are being installed in new homes and how they are operating.
  • Measure and characterize IAQ, ventilation, and the potential sources of indoor pollutants. Include a variety of mechanical ventilation types in the sample.
  • Determine occupant perceptions of, and satisfaction with, the IAQ in their homes.
  • Examine the relationships among home ventilation characteristics, measured and perceived IAQ, and house and household characteristics.

Analysis of the field data will allow us to compare homes that are built to the Title 24 2008 standards, and older homes (pre-2005) that were previously studied by the California New Homes Study. This comparison will show what effect the 2008 ventilation requirements has on IAQ.

The REGCAP model will be used to extrapolate our calibrated distribution to ask the question of what would happen if certain options were pursued in terms of both energy use and IAQ. Input for the simulations will be based on previous studies together with specific measurements and characteristics from the field study component of this project. The simulations outputs include both energy and IAQ and will be based on annual simulations at one minute time steps to capture the interactions of ventilation with HVAC system operation. REGCAP will use the field data to refine its inputs – particularly envelope leakage and ventilation system performance. REGCAP will simulate homes in all relevant California Climate Zones over a range of envelope air leakage values observed in the field data and projected to be used in new net-zero energy homes and possibly in Title 24, and will evaluate ventilation systems representative of those found in the occupant survey and field measurements.