Abstract: A heating system for an electric vehicle heats an interior thereof by the driving force of a drive motor is activated by battery power, and includes: a heat exchanger that is connected to the drive motor via a cooling line circulating cooling water between the battery and the drive motor; a PTC connected to the battery via the cooling line and activated by battery power; a heat storage unit that collects and stores thermal energy from the cooling water, with its temperature raised while cooling the drive motor, and connected in series to the drive motor and the battery via the cooling line; and a valve unit installed in the cooling line interconnecting the drive motor, the heat exchanger, and the heat storage unit, which selectively connects the cooling line to the drive motor, the heat exchanger, and the heat storage unit by opening and closing operations.

Abstract: A coolant heater having a coolant tank and a burner tube within the coolant tank is used for marine and motor coach installations. The burner tube is offset sidewise from the center line of the coolant tank to allow an exhaust manifold to be positioned within the coolant tank and beside the burner tube which allows a predictable coolant movement to more evenly distribute the heat throughout the coolant. An exhaust manifold is positioned within the coolant tank in the space obtained by the burner tube offset which allows an “up” or “down” exhaust duct configuration depending on the heater installation. An expansion tank connected to the coolant tank has a level switch located within the expansion tank and a pump is operably connected to the expansion tank and to the level switch. The pump terminates operation when the level switch indicates low coolant in the expansion tank.

Abstract: A heating and ventilation system for a passenger compartment of a vehicle. The system having a heater core supplied with engine cooling fluid via a variable flow pump for heating an air flow supplied to the passenger compartment. The system additionally having a controller for controlling the pump to increase engine cooling fluid mass flow-rate in response to a detected temperature decrease of the engine cooling fluid when the engine is off.

Abstract: An air conditioning system and a method of heating air flowing through a heater core of a HVAC module is disclosed. The method includes flowing essentially all of the air flowing through an evaporator through a heater core for all HVAC operating conditions. A flow control valve is opened long enough to allow a flow of hot coolant from an engine into the heater core. The valve is then closed to stop the flow of the hot coolant. When the temperature of the hot coolant is determined to have cooled to a predetermined temperature threshold, the flow control valve is then opened again to allow hot coolant to flow into the heater core.

Abstract: A system for supplying supplemental heat to a vehicle, particularly a vehicle with a diesel engine. A driven viscous plate with different viscous clutch faces on either side is provided between the engine and the coolant pump. One side clutches to the engine structure (ground) to generate heat, and the other side clutches to the coolant pump to vary the pump drive. The two sides are controlled by a valve operated by signals from the engine computer. The valve varies the supply of viscous fluid from a common reservoir independently to both sides of the driven viscous plate. The signal from the engine control unit is based on the instantaneous desired supplemental heat and coolant flow. In another embodiment, two separate viscous clutches are utilized and positioned on opposite sides of the coolant pump.

Abstract: A method of conserving energy during a heating event wherein a coolant is heated in a cooling system is disclosed. The method includes establishing a first set point temperature for a first point in the cooling system and establishing a second set point temperature lower than the first set point temperature for a second point in the cooling system. Normally, the coolant is maintained at the second set point temperature at the second set point in the cooling system. During the heating event, the second set point temperature is raised to substantially match the first set point temperature to reduce necessary heating of the coolant at the first point.

Abstract: A system described is for providing improved cabin heating. The system may include a vehicle cabin heating system having a first and second heating system receiving coolant flow from the engine; and a control system for operating the engine at a first engine idle speed upon entering idle speed control operation from previous drive operation, maintaining said first idle speed for a duration, and then increasing engine speed to increase coolant flow to the second heating system during cold ambient conditions when the second heater system is in operation.

Abstract: Disclosed herein is an exemplary supplemental heating system including a hydrodynamic heater and a heat exchanger. The hydrodynamic heater includes a hydrodynamic chamber disposed within an interior cavity of the hydrodynamic heater. The hydrodynamic chamber is operable for selectively heating a fluid present within the hydrodynamic chamber when the heating apparatus is connected to a fluid supply source. The hydrodynamic heater includes an inlet port fluidly connected to a discharge port of the heat exchanger, and a discharge port fluidly connected to an inlet port of the heat exchanger. The heat exchanger includes a heat exchanger core disposed within an interior cavity of the heat exchanger. A wall at least partially defines the interior cavity of the hydrodynamic heater and the interior cavity of the heat exchanger.

Abstract: A system for supplying supplemental heat to a vehicle, particularly a vehicle with a diesel engine, A driven viscous plate with different viscous clutch faces on either side is provided between the engine and the coolant pump. One side clutches to the engine structure (ground) to generate heat, and the other side clutches to the coolant pump to vary the pump drive. The two sides are controlled by a valve operated by signals from the engine computer. The valve varies the supply of viscous fluid from a common reservoir independently to both sides of the driven viscous plate. The signal from the engine control unit is based on the instantaneous desired supplemental heat and coolant flow. In another embodiment, two separate viscous clutches are utilized and positioned on opposite sides of the coolant pump.

Abstract: A compact hydronic space and water heating apparatus and system is disclosed for use in a recreational vehicle. A liquid heating medium, stored within a low pressure tank, is recirculated through a gas fired heater thereby maintaining a desired set point temperature. The liquid heating medium is further circulated through the vehicles hydronic space heaters to heat the interior of the vehicle. Further fresh domestic water is passed through a heat transfer coil within the tank whereby hot domestic water may be provided. An auxiliary heating device is attached to the tank whereby hot combustion engine coolant may assist in maintaining the temperature of the liquid heating medium within the tank and/or reversed to pre heat the combustion engine if and when needed.

Abstract: A coolant system and method of operating the coolant system for a vehicle having a battery pack is disclosed. A method may include detecting a mountain grade descent condition; detecting a battery limit condition; and, if the mountain grade descent condition and the battery limit condition are detected, activating a coolant heater and a coolant pump to thereby accomplish an electric load shed. A method may include detecting a fuel cell stack warm up condition; and, if the fuel cell stack warm up condition is detected, activating a fuel cell coolant heater, a cabin coolant heater and a pump, and directing a coolant flowing through the cabin coolant heater through the fuel cell coolant heater and through a fuel cell stack to thereby warm the fuel cell stack.

Abstract: A water heater for heating potable water used in a boat or vehicle. Exhaust heated by the burner of the water heater is discharged from the burner and is conveyed through an exhaust duct which extends through a water jacket surrounding the burner and which water jacket holds the potable water to be heated. The potable water is heated by the burner and also by the hot exhaust gases in the exhaust duct. Operating components are accessible from one end of the water heater.

Abstract: Disclosed herein is an exemplary supplemental heating system including a liquid heat generator having a hydrodynamic chamber for selectively heating a fluid. The supplemental heating system further includes a manifold having an inlet passage fluidly connectable to a discharge passage of a heat exchanger, a first discharge passage fluidly connectable to an engine cooling system, and a second discharge passage fluidly connected to an inlet passage of the hydrodynamic chamber. A control valve comprising a spool slideably disposed within the manifold controls distribution of the fluid between the manifold inlet passage and the first manifold discharge passage, and the manifold inlet passage and the manifold second discharge passage.

Abstract: A hybrid vehicle can be driven using both of respective driving forces from an engine and a motor. A heating mechanism of an air conditioning apparatus uses thermal energy from cooling water of the engine to heat the interior of a passenger compartment. An ECU takes into consideration engine efficiency from the standpoint of fuel economy enhancement to primarily determine the driving force share ratio between the engine and the motor. Further, the ECU calculates a preset temperature corresponding to a cooling water temperature necessary for desired heating as well as a control target temperature in which the preset temperature is reflected, and corrects the primarily determined driving force share ratio to increase the share of the driving force of the engine by an amount according to a deviation between the cooling water temperature measured by a water temperature sensor and the control target temperature. Heating performance can thus be ensured promptly without deterioration of fuel economy.

Abstract: A washer fluid heater apparatus in embodiments of the invention may include one or more of the following features: (a) a heat exchanger having a washer fluid inlet to allow washer fluid to enter the heat exchanger and a washer fluid outlet to allow the washer fluid to exit the heat exchanger; and (b) a coolant passage traversing through the heat exchanger having a coolant inlet and a coolant outlet, the coolant inlet and coolant outlet operably coupled to an engine's coolant system to allow passage of engine coolant through the heat exchanger.

Abstract: An air conditioning system for automobile having a heater core capable of heating the interior in good efficiency is to be provided. Such a heater core is supplied with the coolant having bubbles removed, and thereby the efficiency of heat exchange is enhanced and the noise is reduced. On the internal combustion engine is mounted a water outlet (bubble separating means) 3 having a receiving chamber 8 that the coolant after cooling the engine flows in. In the downstream position of the chamber 8 is formed a communicating portion 9 of narrowed sectional area and a feeding chamber 10 of increased sectional area in turn. The flowing velocity of the coolant is increased in the communicating portion 9 and decreased in the feeding chamber 10 and thereby it is possible to make bubbles in the coolant float up and separate out. As a result, the coolant without bubbles may be fed to the heater core 7 through a feeding portion 11.

Abstract: The invention is directed to a heating assembly comprising, in combination, a main radiator (1) for fluid flow and an electric radiator. The latter is disposed on one face of the main radiator (1) defining its general plane, and consists of a plurality of independent heating elements (6). Each of these heating elements (6) comprises an elementary electrical heating body (7), having connecting means (31, 31?) for connection to an electrical power source, and a finned element (8). These heating elements (6) are assembled on a connecting structure of the electric radiator on the face of the main radiator (1).

Abstract: The invention relates to a method of heating a motor vehicle cabin by means of a circuit (20) for circulating a cooling fluid for cooling an engine (10) and including a pump (23), an air heater unit (22), and a heat exchanger (21) disposed in an exhaust system (15) that is also provided with a depollution assembly (16). The exhaust gas is directed towards the heat exchanger (21) or towards a bypass duct (18) downstream from the depollution assembly (16) as a function of engine operating conditions, of the outside temperature, of the heating temperature requested in the vehicle cabin, and of the temperature of the engine cooling fluid. The invention applies more particularly to direct injection diesel engines.

Abstract: When a truck engine (12) is not running, an auxiliary coolant heater (32) can heat engine coolant and pump it through an occupant compartment heater (16). A coolant flow control system (10), including a valve assembly (84), associates the auxiliary heater (32) with both the occupant compartment heater (16) and engine (12) for selectively distributing heated coolant. When engine (12) has been running and is shut off, auxiliary heater (32) can be turned on and valve assembly (84) operated for occupant compartment heating while keeping the engine (12) warm. When the engine is cold, the auxiliary heater can be turned on and the valve assembly can be operated for engine pre-heating prior to starting.

Abstract: A diesel/electric appliance for heating coolant within an auxiliary heater circuit and for heating potable water within a potable water circuit. The appliance includes a diesel powered auxiliary heater and a coolant jacket surrounding the burner of the auxiliary heater. Electrical resistance elements are immersed within the coolant jacket to maintain the temperature of the potable water circuit by transferring heat through a heat exchanger to the potable water circuit.

Abstract: A method and apparatus for automatically adjusting the flow rate of engine coolant through a heater core in an automobile by automatically determining a temperature difference between the temperature of coolant at a first flow rate before it enters a heater core and a temperature of air exiting the heater core and automatically increasing the flow rate of the coolant to a second flow rate higher than the first flow rate if the temperature difference is greater than a first predetermined temperature difference.

Abstract: A heating and ventilation system for a passenger compartment of a vehicle. The system having a heater core supplied with engine cooling fluid via a variable flow pump for heating an air flow supplied to the passenger compartment. The system additionally having a controller for controlling the pump to increase engine cooling fluid mass flow-rate in response to a detected temperature decrease of the engine cooling fluid when the engine is off.

Abstract: A heating system for a vehicle having a power plant with a power plant coolant loop, and a method of operation, is disclosed. The heating system may comprise a HVAC module and a heater core coolant loop. The HVAC module includes a heater core. The heater core coolant loop includes a three-way valve having an inlet engaging the heater core for receiving a coolant, a first outlet that directs the coolant back into the heater core coolant loop, and a second outlet that directs the coolant into the power plant; a coolant pump for pumping the coolant through the heater core coolant loop; and a coolant heater located upstream of the heater core that selectively heats coolant flowing therethrough. Also, a coolant line receives the coolant from a heater core outlet of the power plant and directs the coolant into the heater core coolant loop.

Abstract: An air conditioning system and a method of heating air flowing through a heater core of a HVAC module is disclosed. The method includes flowing essentially all of the air flowing through an evaporator through a heater core for all HVAC operating conditions. A flow control valve is opened long enough to allow a flow of hot coolant from an engine into the heater core. The valve is then closed to stop the flow of the hot coolant. When the temperature of the hot coolant is determined to have cooled to a predetermined temperature threshold, the flow control valve is then opened again to allow hot coolant to flow into the heater core.

Abstract: A warming-up system for vehicle includes: a heat storage device having a heat storage element; a first heat transfer medium circuit for causing a first heat transfer medium to circulate through the heat storage device; and a second heat transfer medium circuit for causing a second heat transfer medium to circulate through the heat storage device. The first and second heat transfer mediums flow into first and second warming-up targets, respectively. The heat storage device includes a first chamber in communication with the first heat transfer medium circuit, a second chamber in which the heat storage element is arranged, and a third chamber in communication with the second heat transfer medium circuit. Heat exchange can be carried out among the first heat transfer medium of the first chamber, the heat storage element of the second chamber and the second heat transfer medium of the third chamber.

Abstract: A coolant heater having a coolant tank and a burner tube within the coolant tank is used for marine and motor coach installations. The burner tube is offset sidewise from the center line of the coolant tank to allow an exhaust manifold to be positioned within the coolant tank and beside the burner tube which allows a predictable coolant movement to more evenly distribute the heat throughout the coolant. An exhaust manifold is positioned within the coolant tank in the space obtained by the burner tube offset which allows an “up” or “down” exhaust duct configuration depending on the heater installation. An expansion tank connected to the coolant tank has a level switch located within the expansion tank and a pump is operably connected to the expansion tank and to the level switch. The pump terminates operation when the level switch indicates low coolant in the expansion tank.

Abstract: A closed heating system drawing external power from a small electric generator. The heating system contains a hydraulic fluid drawn through restrictors and pumped through a heat transfer means attached to a means for circulating a heated fluid through a household.

Abstract: The present invention provides a system for controlling the climate of a hybrid vehicle. The system includes a thermoelectric module, a heat exchanger, a pump, and a valve. The thermoelectric module includes thermoelectric elements powered by electric energy. The thermoelectric elements emit or absorb heat energy based on the polarity of the electrical energy provided. A tube containing coolant runs proximate the thermoelectric elements. To aid in the transfer of heat energy, a blower is provided to generate an air flow across the thermoelectric elements and the tube. The coolant is provided from the thermoelectric module to a heat exchanger that heats or cools the air flow provided to the cabin of the vehicle. The pump and valve are in fluid communication with the heat exchanger and thermoelectric module. The pump pressurizes the coolant flow through the tube and coolant lines. In a cooling mode, the valve is configured to selectively bypass the engine coolant system of the vehicle.

Abstract: Disclosed herein is an exemplary supplemental heating system including a liquid heat generator having a hydrodynamic chamber for selectively heating a fluid. The supplemental heating system further includes a manifold having an inlet passage fluidly connectable to a discharge passage of a heat exchanger, a first discharge passage fluidly connectable to an engine cooling system, and a second discharge passage fluidly connected to an inlet passage of the hydrodynamic chamber. A control valve comprising a spool slideably disposed within the manifold controls distribution of the fluid between the manifold inlet passage and the first manifold discharge passage, and the manifold inlet passage and the manifold second discharge passage.

Abstract: A temporary heating apparatus comprises a portable heat exchanger which transfers heat from a hot fluid circulating in a primary circulation loop thereof to a heated liquid circulating in a secondary circulation loop thereof. The heat exchanger is connectable to a hot fluid source such that hot fluid from the hot fluid source circulates through the primary circulation loop. A portable remote heating unit comprises a fluid coil releasably connected by flexible conduits to the secondary circulation loop, and a secondary pump is connected to the flexible conduits and the secondary circulation loop to pump heated liquid through the secondary circulation loop, flexible conduits, and the fluid coil of the remote heating unit. The heat exchanger isolates the heating circuit from the hot fluid source, allowing the use of steam as the hot fluid source, and further allowing high pressures in the heating circuit, such as encountered in tall buildings.

Abstract: The invention relates to a heating device for motor vehicles with an internal combustion engine and a coolant circuit. The heating device (1) comprises a heat-generation compartment (2) with a cooling jacket (6) around which a coolant flows, and a rotor (13) mounted on a drive shaft (9). The cooling jacket (6) is part of a cooling chamber (3) that comprises a coolant inlet (4) and a coolant outlet (5). A pump wheel (17) is disposed in the cooling compartment (3), is driven by the drive shaft (9) and circulates the coolant.

Abstract: The invention relates to a method for estimating a heater-core air discharge temperature of an HVAC system. According to the invention, the method uses a model of the heat exchanger. This heat exchanger efficiency model maps a heat exchanger efficiency to a set of actual operating parameters by generating a heat exchanger efficiency coefficient based on said second set of actual operating parameters.

Abstract: A heat management system is capable of managing unlimited hydronic heat sources and unlimited heating zones, each located within a desired area and each controlled by temperature sensors. The system uses plural system heating sources to heat a heating solution (preferable glycol-based) that is either heated directly or through a liquid-to-liquid heat exchanger. The heating solution is passed through various plumbing configurations to heat domestic water for users and to heat zones or areas in which user will live. The heat management system of the invention may be used for several applications including RV, marine and home hot water and heating applications.

Abstract: A heat generator for a motor vehicle comprises a rotor (1), a stator (13) in which the rotor (1) induces by rotation electrical currents that generate heat in the stator (13), and a coolant duct (16) adjacent to the stator (13) through which flows a liquid for extracting the heat generated in the stator (13). A device for regulating the working temperature of a liquid-cooled internal combustion engine comprises such a heat generator and an actuator (19) for the stator (13) for regulating the heat generated by the stator (13) by changing the distance between the stator (13) and the rotor (1). The stator (13) is mounted to be pivotal relative to the rotor (1) for changing the distance between them and thus for regulating the heat generated in the stator (13) and regulating the working temperature of the internal combustion engine (3).

Abstract: A hot water heating system for use in a boat or vehicle which utilises the engine of the vehicle or boat, an AC power source or a fuel powered heater to heat a living area and to heat potable water. Each of the power sources can be utilised independently or in combination depending on the location and operation of the vehicle or boat. A valve is automatically controlled by a thermostat to allow heated fluid to circulate through the living area or to bypass the area. Aquastats are provided to automatically allow potable water to be heated. A display is provided for displaying textual and numerical information in user friendly format relating to the operation of the hot water heating system.

Abstract: A layover heating system (89) for a locomotive is provided. The layover heating system (89) is adapted to be used in conjunction with a conventional locomotive cooling systems. The layover heating system (89) includes a water tank and pump (90). A layover heater (92) heats fluid in the layover heating system (89). An orifice (98) is provided to control the flow Of fluid in the layover system (89) to generally balance the pressure on either side of the locomotive radiator. In this manner, fluid flow through the radiator is minimized, minimizing heat loss at the radiator. A variable orifice may be used that is adjustable in response to a signal generated from pressure sensors on each side of the radiator and processed by a central processing unit.

Abstract: An extended engine off passenger climate control system utilizes an advanced temperature control module in combination with modifications to the conventional heating/ventilation/air conditioning (HVAC) system to provide occupants in the passenger cabin of a hybrid electric motor vehicle with adequate heat or air conditioning for up to two minutes after the gasoline engine is turned off. A two stage orifice between the condenser and the evaporator of the air conditioning system slows the equilibration of the pressures on the high pressure side and low pressure side of the air conditioning system when the air conditioner compressor is turned off, allowing the passenger cabin to continue receiving cooling air even when the gasoline engine, and thus the compressor, is off. An auxiliary engine coolant pump circulates heated engine coolant through the heater core when the gasoline engine is turned off, thus providing heat when conditions require passenger cabin heating.

Abstract: A compact vehicle heating system and method is provided which includes mechanisms to selectively shut down heating systems. For example, when domestic hot water is required, space heating and engine preheating systems can be shut down in order to provide priority heating to the domestic hot water. When the demand for domestic hot water is lower, the space heating and engine preheat systems can be reactivated.

Abstract: The invention relates to a heating device, in particular for motor vehicles, for generating frictional heat by liquid friction with a housing which is arranged in a stationary position and has a working space and a motor-driven rotor in the working space.

Abstract: The heater (30) is designed for a motor vehicle air conditioning system (10) and has at least one heat exchanger tube (58) which produces a heat conducting connection (54) between a heat generating means (52) and at least one heat releasing means (56) via a medium which vaporizes and condenses in the heat exchanger tube (58). In order to be able to produce the heater (30) more economically, the heat generating means (52) is made with an extruded profile (62, 84) to which at least one heat exchanger tube (58) is coupled by heat conduction.

Abstract: A heating system for a vehicle includes a reformer arrangement for producing hydrogen from a hydrocarbon/mixed material mixture, a burner arrangement for reception of hydrogen produced in the reformer arrangement and combustion thereof, and a heat exchanger arrangement for transferring combustion heat produced in the burner arrangement to a heating medium.

Abstract: The present invention provides a heating apparatus for providing radiant heat to a passenger compartment of a vehicle. Heated fluid is transported from a heat source positioned outside of the passenger compartment. A supply manifold selectively dispenses heated fluid into a plurality of tubular members extending into the passenger compartment. The heated fluid provides radiant heat for heating the passenger compartment. The fluid is transported within the tubular members to a return manifold, wherein said fluid is recycled to the heat source.

Abstract: A cooling system comprising a cooling water circuit 3a in which cooling water of an engine 1 circulates in a radiator 5, a hot water circuit 3c in which hot water circulates in a heater core 11, an air mixing door 12 for adjusting the volume of air which passes through the heater core, a heat storage element 7 provided in a bypass passage 6 for branching hot water into the heat core from the hot water circuit, a flow path selector valve 9 for adjusting the distribution of hot water to the heat storage element and the heater core, and a control unit 14 for controlling the operation of the air mixing door and the flow path selector valve, wherein the control unit controls the flow path selector valve such that the flow rate of hot water to be distributed to the heater core becomes larger than the flow rate of hot water to be distributed to the heat storage element, in the event that the volume of air passing through the heater core is equal to or larger than a predetermined value.

Abstract: An air conditioner for a vehicle having a passenger compartment has an electric-powered hot water pump in addition to a mechanical hot water pump driven by an engine mounted on the vehicle. The electric-powered hot water pump is activated while the engine is stopped. However, the electric-powered hot water pump is kept in a non-activation state while an air mix door is positioned in a low temperature side as compared to a predetermined value and an elapsed time after the engine is stopped is within a predetermined time so that power consumption by the electric-powered hot water pump can be decreased suitable for a hybrid vehicle having a driving motor in addition to the engine.

Abstract: A heating, venting, and air conditioning system utilizes a reformer to provide supplemental heat to a passenger compartment and to improve start-up emissions of an engine of a vehicle or power system. A pump circulates a fluid through the engine and throughout the system. A radiator and heater core transfer heat from the fluid. A first circuit cools the fluid upon circulation through the radiator after circulation through the engine to cool the engine, and a second circuit heats the passenger compartment and cools the fluid upon circulation through the heater core after circulation through the engine to cool the engine. The reformer, which converts a hydrocarbon or alcohol fuel into a reformate, generates heat. A third circuit, defined between the reformer and the pump and interconnected with the heater core, provides the supplemental heat from the reformer to the passenger compartment through the heater core and also to the engine.

Abstract: In a vehicle air conditioner, a flow control member is disposed in an inlet tank of a heating heat exchanger for heating air to be blown into a passenger compartment using a fluid as a heating source. In the heating heat exchanger, a ratio between a first area where the fluid flows, and a second area where the fluid does not flow is changed by controlling an operation position of the flow control member. Thus, a flow ratio between hot air from the first area of the heating heat exchanger and cool air from the second area thereof can be adjusted, so that the temperature of air blown into the passenger compartment can be adjusted.

Abstract: In a vehicle air conditioner, a heater core is disposed in an air conditioning case to heat air so that conditioned air is obtained. The air conditioning case has a rear wall surface extending substantially in a vehicle width direction and in a vertical direction, and a foot opening portion is provided in the wall surface at an upper side position of the heater core to extend in an entire width dimension of the wall surface in the vehicle width direction. A foot air duct is connected to the wall surface around the foot opening portion, and extends downwardly to be tilted toward right and left sides. Foot air outlets are provided at a bottom end of the foot air duct to be opened downwardly. Thus, a flow resistance in a foot air-outlet passage can be reduced, and air can be uniformly blown toward a foot area.

Abstract: A powertrain thermal management system for a hybrid vehicle having provisions for passenger cabin heating and engine warm up.

Abstract: An HVAC system including a housing, an evaporator assembly, a heater core assembly, an air inlet assembly, a fan assembly, and a film valve assembly including first and second rollers, wherein each roller includes a biasing member with a constant force urging the biasing members to rotate and the biasing members are biased in opposite directions.

Abstract: A heating system is provided for heating fresh water on boats, marine vessels and the like. The boat's water supply is connected to a hot water tank, which in turn is in fluid communication with a heat exchanger. The coolant line for a boat engine passes through the heat exchanger, through the hot water tank and back to the engine. Heat from the engine is transferred from the coolant line to the water in the hot water tank at a rate that varies with engine operation. The heat exchanger allows additional heat transfer to the water as the coolant and water pass through the heat exchanger. A sensor regulates circulation of water through the heat exchanger. The heat exchanger may be retrofitted externally of an existing hot water tank by connecting the heat exchanger to existing water lines for the hot water tank and to an existing engine coolant line to effect heat transfer from the engine coolant line.