Low-Cost Energy Recovery Ventilator Incorporating a High Flux Moisture-Permeable Membrane

Substantial improvements to the integrity of residential building envelopes have been realized in recent years with the use of advanced house wraps, fenestration, and air sealing technologies. While tight construction significantly lowers residential energy consumption, the concomitant reduction in natural ventilation results in less frequent air turnover that can adversely impact indoor air quality and occupant comfort. The addition of mechanical exhaust ventilation may improve comfort and air quality through increased air circulation and contaminant dilution, but without conditioning of the make-up air, the infiltration of cold dry air in the winter and hot humid air in the summer can significantly increase HVAC loads. An energy recovery ventilator (ERV) that transfers heat and moisture between supply and exhaust air streams will be developed and demonstrated in the proposed program. The ventilator utilizes a high performance, low-cost water-permeable membrane to substantially increase ERV efficiency while simultaneously reducing ERV cost. A scalable method for producing a low-cost membrane that transfers humidity at over three times the flux of existing membranes was demonstrated. Membrane performance and durability was demonstrated over a wide range of conditions of relevance to ERV operation. The performance of ERV cores that incorporate the membrane was modeled, and ERV life-cycle energy and cost savings were predicted. Membrane chemistry will be optimized in order to ensure that the membrane exceeds all of the requirements of residential and commercial ERV systems. The membrane fabrication process will be scaled up in order to support the design and assembly of multiple next-generation ERV cores. The cores will be installed in full-scale residential ERV systems and multiple demonstrations will be conducted.Commercial Applications and Other Benefits Development of the proposed energy recovery ventilator will significantly increase the life cycle cost savings and shorten the payback period associated with ERV use, thereby accelerating residential and commercial ERV adoption throughout the U.S. The membrane technology is also well-suited to other moisture management applications, including humidifiers, medical equipment, pharmaceuticals, fuel cells, and sensors.