These ERV/HRV configurations are NOT recommended because outdoor air can be sucked back into the ERV/HRV before being distributed to the living space

Reference

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Author(s)

Aldrich Robb

Organization(s)

Consortium for Advanced Residential Buildings,

CARB,

Steven Winter Associates,

SWA,

U.S. Department of Energy,

DOE

This document addresses adding—or improving—mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes either directly or by dilution. This report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards.