Broan GSHH3K 270 CFM Hepa Filtration and Fresh Air Ventilation with Heat Recovery Ideal for Homes up to 6,000 Square Feet Delivers 270 CFM Of Fresh Clean Air Into The House. The Most Comprehensive Indoor Air Quality Strategy Available In The Market Our Heat Recovery Core Allows Outgoing Stale Air To Temper Fresh Incoming Air Without Cross Contamination Fully Integrated Whole-House Hepa Filtration with Fresh Air Ventilation and Heat Recovery - Minimizes Dust and Allergen Material as Small as 0.3 Microns. Three Products In One