Separating the conditioning of ventilation air from the general heating and cooling results in significant opportunities for reducing total energy use required by an HVAC system and improves the quality of provision of outside air to all spaces. Heat and energy recovery ventilation systems heat incoming air using the thermal energy in the exhaust air. Use of water or refrigerant rather than air dramatically reduces the energy required for transport heating and cooling to various locations in the building. Examples of systems using this combined approach (energy recovery and heat pumps) will be provided. Examples will include retrofit of an existing commercial building previously served by rooftop (air handling) units, a new design for a Passive House residence, and a proposed conversion of a large institutional building from a VAV system to dedicated outside air and heat pump systems. Applications of ducted and ductless heat pumps will be included. Other case studies for institutional, commercial and residential applications will also be provided.