9. Create an Energy Efficient, Fresh Air Supply and Manage
- Install a highly efficient Energy Recovery Ventilation (ERV) or Heat Recovery Ventilation (HRV) system to provide fresh filtered air. Learn more about HRVs and ERVs from Green Building Advisor
- Depending on energy modeling results, consider selecting the more energy efficient HRV or ERV systems, such as the UltimateAir RecoupAerator 200DX ERV, the Venmar EKO 1.5 HRV or the Zehnder ComfoAir, or consider less efficient, lower cost units such as Life Breath ERVs and HRVs or Panasonic WhisperComfort ERV. View the Heat Recovery Ventilation video.
- Plan for and manage moisture. In most homes, but especially airtight homes, indoor winter humidity should be 30% or a little below, to avoid possible condensation problems. While utilizing either a HRV or an ERV will help manage interior humidity, an HRV may help lower indoor humidity more effectively, when the outside humidity is low. The use of vapor barrier paint on the interior of the sheet rock will help prevent moisture from penetrating the wall assembly. And just moving the air regularly with either type of ventilation system will help prevent mold.
Twelve Steps to Affordable Zero Energy Home Construction