Engineered Ventilation

If engineered ventilation is installed, or you are considering engineered ventilation for the home, fill in the corresponding fields in the HVAC system / engineered ventilation section. HRV and ERV efficiency ratings are entered as a decimal number, so an ERV unit with sensible and latent efficiency ratings of 65 and 56 are entered as .65 and .56 respectively.

When there is just an exhaust fan running (no intake) it typically means you are relying on creating a negative pressure situation and using infiltration to make up the fresh air.