Contaminant Crossover in Residential Energy Recovery Ventilators: Mass Spectrometric Analysis and Introducing Remediation Measures

Abstract

Background and Objective: Energy Recovery Ventilators (ERV) are increasingly present in residential environments to enable the energyefficient provision of controlled outdoor air ventilation. In this work, we investigated pollutant transport through a typical residential ERV as a potential pathway for re-entrainment of indoor air pollutants into the outdoor ventilation air supplied to an indoor space. Specifically, we investigated the transfer of Volatile Organic Compounds (VOCs) through the sandwiched membrane matrix of the ERV core, between two adjacent air streams. Materials and Methods: Pollutant transfer efficiency is calculated for experiments intentionally injecting two common indoor VOCs (acetone, Isopropanol (IPA)) and the behaviour of transfer is studied for different ERV exhaust and supply flowrates (supply, exhaust, balanced scenarios). Results: Maximum pollutant transfer efficiency of 17% is recorded for isopropanol at balanced (equal supply and exhaust airflow rates) conditions at intake and exhaust airlines. Maximum pollutant transfer efficiency of 26% and a minimum of 5.3% for unbalanced CFM settings are obtained. For VOCs studies, we observed short response times of <10s from starting injection of VOCs into the indoor exhaust air stream until the concentration at the indoor supply air stream reaches to steady state. Conclusion:The airflow rates of intake and exhaust streams of a typical membrane ERV can tremendously impact the contaminant crossover back to the residential space. Also, a membrane ERV can demonstrate a fast response to contaminant crossover.