The present invention relates generally to heating systems for recreational vehicles, and more specifically, to a controller for recreational-vehicle heating systems.
Heating systems for campers and recreational vehicles are widely known. Conventional water heating systems for recreational vehicles generally fall into two classes. The first class includes systems that have a heating element(s) that extends into a cavity that holds several gallons of water. The heating element ultimately heats the entire volume of water in the cavity. Drawbacks to this first class include a lack of continuous hot water. In addition, the first class of systems takes a relatively long period of time to heat water. The second class involves systems that heat a relatively small volume of water with a gas or electric heating device. Conventional systems of the second class include propane, or other open flame “flash furnace” heating systems that directly heat domestic water supplied to the system. Open-flame systems like these are relatively expensive and relatively unsafe when used in a recreation vehicle. In addition, a propane system is ineffective to provide a constant supply of hot water.
The controller of the present invention can be used with any conventional recreational-vehicle heating system (the “RV-heating system”), but preferably uses the one described in the following pending U.S. nonprovisional patent applications: Ser. No. 10/421,365 for an invention entitled HEATING SYSTEM and Ser. No. 60/380,586 for an invention entitled HEATING SYSTEM. The controller described in this application is intended to replace and/or augment the controller described in the pending applications.
The heating system in the above mentioned patent applications includes several features that incorporate use of the controller of the present invention and can allow the user to be informed about the status of the system and its components, including: (i) a detector to inform the user about the status of an electric back-up heater; (ii) independent controls for each heat source of the system; (iii) a control panel coupled to the system for remote positioning therefrom, and equipped with actuators necessary for controlling all heat sources of the system; (iv) a text-display capability for displaying at the control panel messages informing the user about the status of components of the system including the heating sources, temperature of the heating solution (preferably glycol), the temperature of hot water, and status of the fans located in areas desired to be heated such as cabins of a recreational vehicle; and (v) refill and service warning indicators displayable at the control panel to inform the user if one of the system fluids needs to be refilled or if the system requires service (based upon preselected criteria such as passage of time, fault detection of a system component(s).
Additional status-communication features include: (i) display of fault codes associated with a diesel-fired heater of the system both as a flashing LED display coupled to the actuator of that heater, and a textual message displayable simultaneously on the control panel; (ii) fluid-level sensors that monitor the fluid level of the heating solution contained in an expansion tank and provide information to control circuitry of the system to stop all system heating sources if the fluid level of the heating solution falls below a preselected threshold.
The heating system also includes several programmable features preferably achieved using software incorporated within the controller of the present invention so that each can be adjusted without requiring new hardware, and those features include: (i) a water-heating cycling feature that maximizes the capability and efficiency of the system heat sources by using plural heating solution temperature ranges for automatic actuation/de-actuation of each system heat source depending upon whether the user demands domestic hot water (e.g. system heat source(s) are actuated if water temperature falls below 150° F. and de-actuated if heating solution temperature reaches 180° F.) or area heating (without demand for domestic hot water)(e.g. system heat source(s) are actuated if heating solution temperature falls below 120° F. and de-actuated if heating solution temperature reaches 180° F.), (ii) a heat source priority controller governing situations when different ones of the heating sources of the system are actuated depending upon pre-selected factors such as heating source availability, user-demand requirements, etc.; (iii) an engine preheat loop that allows bi-directional heat transfer from and to the engine to allow for various engine situations such as vehicle-engine applications (RV and marine) as well as home-heating engine applications affording the capability to deice a driveway; (iv) a time-based de-actuator feature that disables an engine-preheat pump after a preset period of time to avoid undesired drainage of associated engine batteries and excessive wear of the pump
The controller (also referred to herein as control structure or control board) of the present invention and of the heating system previously described can be constructed to control and direct the flow of the heating solution through plural preselected loops such as a short loop supporting demand for hot domestic water but not heat (summer applications) and a long loop supporting demand for both hot domestic water and heat (winter applications). The controller can also be constructed to optimize heating efficiency and cost by having the capability of sensing whether any thermostat of the system becomes active, and responding to such sensing by activating a by-pass solenoid (that may be plural-way including two- or three-way) that allows the heating solution to circulate through the long loop.
The controller can also be programmable for automatic actuation/de-actuation of heating-area fans (such as cabin fans) when system heating solution temperature is over preselected minimum such as 110° F. (actuation) or under a preselected maximum such as 110° F. (de-actuation), when circulating water pumps, and for by-pass of the long loop solenoid if heat is unavailable. The heating system can include a set of temperature sensors that allow the control board to determine when heat is available from system heat sources and to determine when the cabin fans, circulating water pumps and by-pass solenoids are deactivated or activated.
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Subsystem 15 may be provided with one or more ports 34 that allow external heating sources to be connected to the subsystem to provide supplemental heat to heat the heating solution. Referring back to
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When the temperature sensor installed on the tank detects that the heating solution has reached 110° F.-120° F., it sends a signal to the controller 12 informing it that heat is available and usable. If one of the heating zones 18 (
There is bi-directional communication between the controller and the system heating sources via the actuators of each heating source. Each temperature sensor is mounted adjacent the region of the system where heat from the heating source is transferred to the heating solution. Information from all system temperature sensors provides the controller with necessary input about the existence of heat into the system. To ensure that the information is available to the controller, it is constructed to continuously scan associated temperature sensors of the system heating zones temperature sensors to determine when a given zone is active.
Once the two conditions are met (the controller learns that heat is available and the user requests heat by actuating a heat zone), the controller activates the heating-solution circulation pump which pumps the heating solution through preselected loops of the system because the system includes a series of heating loops. However, the transfer of heat from the heating solution will take place only where the heating zone(s) has been actuated by the user. The heat transfer is done using a combination of one or more of the following: liquid-to-liquid heat exchangers, cabin fans, or by-pass solenoids in conjunction with fine tubes (see
One of the biggest advantages of the controller in combination with the heating systems described is that it makes possible the integration of an unlimited number of hydronic heating sources without restriction on size or shape. The four shown in
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Controller 12 is also programmable for automatic actuation/de-actuation of heating-area fans (such as cabin fans shown in
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The control board can use a 40 amp power-in connection 115 and two 18 pin amp connections—one used for a user interface 116 and one for a system interface 117. User interface 116 can include any number of connections. In one embodiment of the user interface, for example, thermostat connections T1-T5, fan connections F1-F5, heater pump connection (HTR PUMP), two ground connections (GND), two heat sensor connections (HEAT SENS) that activate fans at 120° F., one thermostat out (T-STAT OUT) connection to power T1-T5, and two domestic hot water connections (D/W AQ) to operate aqua stat mounted to a hot water tank can be included. Similarly, system interface 117 can include any number of connections. In one embodiment, for example, sixteen connections can be used for controlling a furnace (e.g. hydronic furnaces such as 55XLT and DEH 65 and other Espar™ furnaces manufactured by Espar Heating Systems of Ontario, Canada) and its components including connections for a heater pump (HTR PMP), summer/winter solenoid (S/W), engine preheat pump (ENG PUMP), two domestic water aqua stats (D/W AQ), two 24 volt outputs to the furnace (24+ OUT), heater on/off (HTR ON/OFF), pump output (PUMP OUT), heater fault code (HTR FLT), two grounds (gnd), two 120° F. heat sensors for fans (HEAT SENS), and two low level indicators (LEV).
The control board can be solid state with no moving parts. It can have six resetting fuses, fourteen indicator lights, an eight-pin modular jack, two manual switches including a pump override (e.g., prime) switch 118, which when “on” overrides all logic in the system even with power switches off, and a master (e.g., main) on/off switch 119. An eight pin phone jack (e.g., remote plug) 120 can feed a remote panel with four switches including master on, furnace on, domestic water on, and engine preheat on.
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In the exemplary embodiment, five thermostat inputs plus an optional sixth are on the controller. Each thermostat controls a heater fan (controlled by heater drivers 811) with a circuit configuration to minimize false thermostat readings, such as AC noise. When the remote furnace switch 804 is triggered, a signal is sent to inverter logic 807 which instructs internal power inverter (24 volt power supply) 808 to provide 24 volt power to the furnace and furnace pump drivers HP1 and HP2 shown by 809. The furnace power supply signal is represented by PS in the diagram. The furnace pump must run when the furnace is running The furnace pump can also run independently of the furnace when the heating solution is greater than 120° F., as a means for distributing heat without further heating the solution in the furnace. Pump drivers 809 can be under the control of pump logic 810 through which the incoming signals to pump drivers 809 flow. Pump logic 810 can be activated by prime switch override (518 of
The heating system can also be fired when the domestic water aqua stat, which is mounted to the hot water tank, calls for heat. The aqua stat fires the furnace when it is mounted to the domestic water heat exchanger that is built into a hydronic furnaces (e.g a DEH65 model) and utilizes domestic water (DW) heater driver 812. When the system is operating properly, the control board will show green lights. When the system is not operating properly, the control board will show red lights. The fault code light for the furnace is a green blinking light on the control board and a red blinking light on the control switch. The remote panel has a red “on” light for each switch.
A separate engine preheat loop can also be incorporated into the heating system and directed by the controller. The engine preheat function on the controller operates the engine preheat pump mounted to an engine (not shown), runs on a 15-minute timer via an EP Timer and Driver 813, and can be reset by turning the engine preheat (EP) switch 814 on the remote panel off and back on. System interface 803 is receiving input from various components of the heating system and sending information to heater output logic 815 and LEDs via switches (shown by SW 1, 2, 3). Heater output logic 815 processes the information received and sends out signals (represented by HO) to control the heating system.
Control board dimensions can be 6¼ inches long, 4½ inches high and 1½ inches deep or any other size as appropriate. Various fuses or similar devices can be utilized throughout the heating and control system to provide circuit protection and/or monitor proper functionality and voltage/communication and determine where faults occur when they might happen. Circuit protections can include internal self re-setting fuses (817) with LED indicators when open on critical power circuits, sensitive transistors can have static input, and there can be limited reverse polarity protection. Another safeguard in the controller that can be used is a low voltage warning 818 that simply activates a red (or other color) LED when there is low voltage. Various heating solution temperature cutoffs can be utilized, for example 125° F. in lieu of the 120° F. noted in the example above.
The disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof, as disclosed and illustrated herein, are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed herein.
This application claims the benefit of Rixen, U.S. Provisional Patent Application No. 60/774,481, entitled “CONTROLLER FOR RECREATIONAL-VEHICLE HEATING SYSTEM” filed Feb. 16, 2006, which is hereby incorporated by reference herein. This application is a continuation-in-part of Rixen, et al. U.S. patent application Ser. No. 10/421,365, entitled “HEATING SYSTEM,” filed Apr. 22, 2003, which is hereby incorporated by reference herein.
Number | Date | Country | |
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60774481 | Feb 2006 | US |
Number | Date | Country | |
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Parent | 10421365 | Apr 2003 | US |
Child | 11707633 | US |