Vehicle HVAC System for Using Passenger Compartment Heat for Operation

A method for operating an HVAC system, comprising:

• providing a heat exchanger configured to be disposed within a vehicle, the heat exchanger comprises a first surface and an opposite second surface, wherein a body of the heat exchanger is disposed between the first and second surfaces, wherein the body includes a first portion and a second portion that is different from the first portion;
• a first air inlet configured, when installed within the vehicle, to receive air that flows therein from a blower through the first surface, wherein the blower can receive either air from a passenger compartment of the vehicle and/or air from outside of the vehicle, wherein air is directed to flow from the blower through the first inlet and into the first portion of the heat exchanger;
• a second air inlet different from the first air inlet, the second air inlet disposed to direct air received therethrough into the second portion of the heat exchanger, the second air inlet configured to receive air that flows therein from within a passenger compartment of the vehicle;
• the heat exchanger is disposed to direct air from the first air inlet through the first portion of the heat exchanger and the heat exchanger is disposed to direct air from the second air inlet through the second portion of the heat exchanger simultaneously;
• wherein the first air inlet is positioned to cause air flow through the heat exchanger at a first position within the heat exchanger that is vertically above a second position within the heat exchanger,
• further comprising a first air outlet configured to receive air from the heat exchanger that flowed from the second air inlet and through the second portion of the heat exchanger, wherein the first air outlet is aligned to direct air that flows into the first air outlet to flow outside of the vehicle,
• wherein the second air inlet comprises a first valve disposed therein, wherein the first valve is positionable in a first position to allow air to flow into the heat exchanger through the second air inlet, and a second position to prevent or substantially prevent air to flow into the heat exchanger through the second air inlet,
• the first valve extends along a cylindrical profile with an outer circumference that extends along a length thereof between first and second ends, wherein a portion of the outer circumference includes a blocking portion to prevent air flow past the blocking portion and into an inner volume of the cylinder, and a portion of the outer circumference is not blocked to allow flow therethrough and into the inner volume;
• and
• a second valve disposed downstream of the first air outlet, wherein when the second valve is in a first position air that flows through the second air inlet and the second portion of the heat exchanger can flow past the second valve and toward the second air outlet, and when the second valve is disposed in a second position air that flows through the second air inlet and the second portion of the heat exchanger is prevented from flowing to the second air outlet;
• further providing a third valve disposed in conjunction with an air inlet upstream of the blower that controls air flow from a passenger compartment of the vehicle toward the blower, wherein when the third valve is open, air from the passenger compartment of the vehicle is drawn into the HVAC system and into the blower, and when the third valve is closed, air from within the passenger compartment of the vehicle is prevented from being drawn into the HVAC system and into the blower;
• providing a a controller that is configured to control the positions of the first valve, the second valve, and the third valve,
• wherein the controller receives a first input representative of a velocity that the vehicle is traveling,
• wherein when the first input indicates that the vehicle is not moving or is moving at a velocity below a threshold velocity, the controller causing the first valve to be in the second position, and the third valve to be in the open position,
• wherein when the first input indicates that the vehicle is moving at a velocity above the threshold velocity, the controller causing the first valve and the second valve to each move to the first position.