HVAC units; Geothermal-based HVAC units; Fans for HVAC units; Air filters for HVAC units; Fan blades for HVAC units; Cross flow fans for HVAC units; Blower wheel housings for HVAC units; HVAC refrigerant line sets comprised of pipes for connecting indoor and outdoor units; Fan blade assemblies for HVAC units; Ventilation hoods; Laboratory ventilation hoods; Air impellers for ventilation; Ventilation hoods for laboratories; Ventilation hoods for stoves; Ventilation fan accessories, namely, gri...