EcoVent is designed to meet real world verification testing and code compliance. Raters are using balometers to verify airflow of installed vent fans prior to certifying they meet ASHRAE 62.2. Panasonic EcoVent ... think of it as a Verification Assurance policy. Low profile and compact (4-3/4 Depth x 7-7/8 Length x 7-7/8 Width).