From Modine Airsystems (Racine, WI) comes the Series QVA/QV line of variable-air volume, direct-fired, makeup air units are available in 15 model sizes and eight configurations and have Btuh capacities ranging from 400,000 to 7 million and airflow ratings up to 60,000 cfm. During off-peak and reduced-load operation, the variable-frequency drive varies the airflow from 100% down to 30% of the full-rated capacity.