The Hi-Velocity System is an energy efficient air delivery system that can be designed to provide heating, cooling, filtration, ventilation, humidification and dehumidification. The Hi-Velocity SDHV (Small Duct High Velocity) System works on the principle of pressure rather than air velocity. It is quite different than a conventional furnace, the main difference being that the supply duct work is all "small diameter" or "mini duct". This makes it very easy to install inside existing walls with minimal remodelling. The flex duct fits inside a typical framed wall without having to disturb the drywall. Our fan coil is modular and fits easily in mechanical rooms, closets, attics, crawlspaces, anywhere! The small footprint makes it the right choice for both new construction and retrofits.