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 building energy consumption, the concomitant reduction in natural ventilation results in less frequent air turnover that adversely impacts indoor air quality and occupant comfort.Although indoor air quality and occupant comfort can be readily improved via mechanical exhaust ventilation, without conditioning of the supply air, the introduction of fresh cold dry air in the winter and hot humid air in the summer significantly increases building 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, lowcost moisturepermeable membrane to substantially increase ERV efficiency while simultaneously reducing ERV cost. A scalable method for producing a lowcost membrane that transfers humidity at more than twice the flux of existing membranes was demonstrated. Membrane performance and durability was demonstrated over a wide range of conditions of relevance to ERV operation. Residentialscale ERV cores that incorporate the membrane were designed, assembled, and demonstrated to operate at significantly higher efficiency than current ERV products. Membrane and core production cost models were refined and ERV life cycle energy and cost savings were predicted. The membrane formulation and rolltoroll production process will be refined in order to improve membrane performance and reduce projected production costs. ERV core designs will be optimized to increase core efficiency while also improving core manufacturability. A series of nextgeneration ERV cores will be assembled, installed in residential ERV systems, and multiple demonstrations will be conducted. 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 wellsuited to other moisture management applications, including humidifiers, medical equipment, pharmaceuticals, fuel cells, and sensors.