An improved HVAC system is provided for the delivery of a temperature controlled air supply via one or more air curtains provided at windows, doors and walls. The air curtains create a double layer of insulation over the surface of a window, door or wall. The invention provides for the use of the temperature controlled air flow from the air curtain to directly affect the interior room temperature. The invention provides an improved system for continuous cleaning the recycled air through the use of a wet electrostatic precipitator in the HVAC air flow, as well as providing a higher speed mode for the air curtain to prevent the inflow of particles and contaminants from outside of the building, when windows or doors are open. The invention may be installed on existing construction, or incorporated as part of new construction.