Southface Energy Institute and partners are developing and validating an assessment protocol incorporating low-cost (IAQ) sensors for homes by monitoring four new-construction homes in Charleston, South Carolina, with “smart” energy recovery ventilators (ERV). The team will also assess occupant comfort between continuous ventilation and time-varying ventilation modes toggling biweekly. The performance-based approach and smart ERV solution will achieve annual HVAC energy cost savings of approximately $100 compared to central fan integrated supply system, as well as a 50% reduction in ventilation-related latent loads compared to supply or exhaust ventilation strategies. This technology will contribute to overcoming homebuilder reluctance around airtightness and ventilation strategies, enabling energy savings from tight construction in hot and humid climates while reducing IAQ risks and improving comfort.

Progress

• Collaboration with Senseware to select low-cost IAQ sensors for sensor package.
  • Senseware IAQ package now commercially available.
• Collaborated with Brone/Venmar to modify smart ERV to remotely toggle between “smart”/“continuous” modes using Senseware platform.
• Collaborated with NREL to modify BEopt program to include CFIS modeling.
  • CFIS modeling capability now publicly available. 
• Completed baseline performance of Senseware sensor package prior to deployment.
• All four Charleston homes have been performance tested, have sensors and monitors installed, and the ERVs are online.
• Monitoring and analyzing performance data, toggling biweekly, and quarterly check-in and filter change.

Data Observations

• Likely seeing volatilization of dust and/or semivolatile organic gases that have deposited on the heat exchanger.
• Volatized chemicals recondense into particles in the air as it cools in the home; team’s PM_2.5 sensors are able to see this.
• Expectation is that this should wane after more cycles.
• Furnace PM_2.5 generation appears to have steadily declined and stopped in all houses after about a month.

• Continue ERV mode toggling and quarterly site visits.
• ERV performance analysis with Venmar.
  • Effectiveness and latent/sensible load calculation at each time interval.
• Initial IAQ data analysis with Emory partners.
• Occupant comfort and comfort metrics with Emory partners.
• Complete BEopt models and ASHRAE relative exposure calculations for each house.
• Retrieval of sensors and test-out.
• Sensor drift test.
• Share results with stakeholders to improve their products and homes.
• Develop actionable guidance for builders and designers on smart ventilation solution.

For more information, visit the Performance-Based IAQ and Optimized Ventilation web page.

Related Publications

Technical Report: Field Validation of a Smart Energy Recovery Ventilation System Using Low-Cost Indoor Air Quality Sensors

Fact Sheet: Smart Control Logic for Mechanical Ventilation in Humid Environments