Systems and methods for mitigating ice formation conditions in air conditioning systems

Some embodiments provide a system or a method to switch off an air conditioning system when an ice formation condition is present. The ice formation condition is present when the temperature, in either degrees Celsius or Fahrenheit, at an indoor evaporator unit or an indoor evaporator coil is below a threshold temperature. Some embodiments allow a user to change the threshold temperature. The system can include a user interface to provide notifications when an ice formation condition is present.

BACKGROUND

Field

This disclosure is related generally to mitigating ice formation in an indoor evaporator unit of an air conditioning system.

Description of Related Art

Air conditioning systems can remove heat from the interior of an occupied space to improve the comfort of occupants. Air conditioning can be used in various environments. Air conditioners can be used to achieve a more comfortable interior environment, typically for humans or animals; however, air conditioning is also used to cool and/or dehumidify an interior space, including spaces containing items such as computer servers, power amplifiers, and artwork.

Air conditioners can use a blower to distribute conditioned air to an occupied space in a building to improve thermal comfort and indoor air quality. Electric refrigerant-based air conditioning units range from small units that can cool a small room to massive units installed on the roof of office towers that can cool a large building. The cooling can be achieved through a refrigeration cycle. An air conditioning system can include an outdoor condenser unit and an indoor evaporator unit connected to each other with a refrigerant circuit.

SUMMARY

Some disclosed embodiments provide a system or a method to switch off an air conditioning system when an ice formation condition is present. The ice formation condition is present when the temperature, in either degrees Celsius or Fahrenheit, at an indoor evaporator unit or an indoor evaporator coil is below a threshold temperature. Some embodiments allow a user to change the threshold temperature. The system can include a user interface to provide notifications when an ice formation condition is present.

This disclosure describes example systems and methods for mitigating ice formation in an indoor evaporator unit of an air conditioning system by monitoring for ice formation conditions in the indoor evaporator unit and terminating the air conditioning system when there is an ice formation condition present. Sensors are operatively connected to the indoor evaporator coil of the indoor evaporator unit. The sensors monitor temperature of the indoor evaporator coil and transmit a signal to a hardware processor. The hardware processor receives the signal from the sensors and compares the signal to a threshold value. When the hardware processor determines that the temperature of the indoor evaporator coil is less than the threshold value, it generates a notification and switches off the air conditioning system. The system may be provided to existing air conditioning systems with a wide variety of air conditioning unit configurations.

Thus, in accordance with some embodiments, a system for mitigating ice formation in an indoor evaporator unit of an air conditioning system comprises a temperature sensor responsive to thermal energy of the indoor evaporator coil, the temperature sensor attached to the indoor evaporator coil of the indoor evaporator unit, the temperature sensor comprising a thermal contact in thermal communication with the indoor evaporator unit, the sensor configured to generate a thermal data associated with the temperature of the indoor evaporator coil. The system can also comprise a hardware processor in electronic communication with the temperature sensor. The system can also comprise a memory device in electronic communication with the hardware processor, wherein the memory device can store information comprising a threshold temperature value and machine readable instructions. The system for mitigating ice formation can further comprise a user interface device comprising a display configured to display a maintenance indicator in response to the hardware processor generating the notification signal.

In some embodiments, the sensor can be coupled to an inlet of the indoor evaporator coil. The sensor can also be coupled to an outlet of the indoor evaporator coil. In the alternative, the sensor can also be coupled to any location between the inlet and the outlet of the indoor evaporator coil.

In some embodiments, the machine readable instructions stored in the memory device, when executed, cause the hardware processor to receive the thermal data from the sensor. The machine readable instruction can also determine a temperature parameter of the indoor evaporator coil using the thermal data received from the sensor. For example, the thermal data from the sensor can be in resistance, current, and/or voltage. The hardware can determine the temperature parameter of the indoor evaporator coil from the thermal data using either a look-up table or an algorithm. The machine readable instructions can also cause the hardware processor to compare the temperature parameter of the indoor evaporator coil to the threshold temperature value and determine that ice formation conditions are present when the temperature parameter of the indoor evaporator coil is less than or equal to the threshold temperature value. In response to determining that ice formation conditions are present, the hardware processor can shut off the air conditioning system and generate a notification signal. In some embodiments, the notification is displayed on the user interface device until additional input is provided.

In some embodiments, the user device is a mobile device. The user interface device can be an electronic device located inside the system or a building. In other embodiments, the user interface device is a thermostat in a building or a house.

In certain variants, the thermal data received from the temperature sensor comprises at least one of voltage, current, or resistance associated with the temperature of the indoor evaporator coil. The thermal data can be collected, by the sensor continuously or intermittently.

Further, in some embodiments, the threshold temperature value is between 25 and 32 degrees Fahrenheit. In other embodiments, the threshold value can be that of voltage (in volts), current (in ampere), or resistance (in ohms). For example, the temperature sensor can generate a voltage reading and transmits that voltage reading to the hardware processor. The hardware processor, in turn, compares the voltage reading to the threshold value in volts. The temperature data generated and transmitted to the hardware processor can be in amperes or ohms. Likewise, the threshold value can be in amperes or ohms.

In certain variant, the system for mitigating ice formation in an indoor evaporator unit of an air conditioning system comprises a relay comprising a first position and a second position. The relay in the first position can allow the air conditioning system to receive power from a power supply, and preventing the air conditioning system from receiving power from the power supply while the relay is in the second position. In some embodiments, the relay can be biased to stay in the first position and be moved from the first position to the second position when the ice formation condition is present.

In some aspects, a method of mitigating ice formation in an indoor evaporator unit of an air conditioning system can comprise receiving thermal data from a sensor in thermal communication with the indoor evaporator unit of the air conditioning system, the sensor responsive to thermal energy of the indoor evaporator unit. The method can further comprise comparing the thermal data of the indoor evaporator coil to a threshold value. The method can further comprise determining that an ice formation condition is present based on the comparison between the thermal data of the indoor evaporator coil to a threshold value. The method can also comprise shutting off the air conditioning system in response to determining that an ice formation condition is present.

In accordance to some variants, a method for installing a system to mitigate ice formation in an indoor evaporator unit of an air conditioning system can comprise installing a sensor to a first location of an indoor evaporator coil of the indoor evaporator unit. The sensor can comprise a thermal contact in thermal communication with the indoor evaporator unit, and configured to generate a thermal data associated with a temperature of the indoor evaporator coil. The method for installing the system to mitigate ice formation can also comprise establishing a connection between a hardware processor and the sensor. The method for installing the system to mitigate ice formation can further comprise installing a relay coupled to the hardware processor and a power supply for the air conditioning system. The relay can comprise a first position and a second position, the relay configured to prevent the air conditioning system from receiving power from the power supply when in the second position. In some embodiments, the hardware processor, in response to determining that an ice formation condition is present, can move the relay from the first position to the second position to shut off the air conditioning system.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments described herein have several features, no single one of which is indispensable or solely responsible for their desirable attributes. Without limiting the scope of the claims, some of the advantageous features of some embodiments will be described.

Some embodiments provide a system comprising a hardware processor with a memory device and at least one sensor. The system can include a mode of operation configured to determine that ice formation conditions are present in the indoor evaporator unit of an air conditioning system. The mode of operation can be configured to switch off the air conditioning system when ice formation conditions are present in the indoor evaporator unit of the air conditioning system. The system can include various types of sensors configured to detect voltage, current, resistance, or temperature. The system can be modular and be installed to an existing air conditioning system.

FIG. 1is a schematic of an embodiment depicting a hardware processor140and an air conditioning system100comprising an indoor evaporator unit110, a sensor130, an outdoor condenser unit170, and an air conditioning system control board150. The hardware processor140is operatively connected to the sensor130and the air conditioning system control board150, and the sensor130is operatively connected to the indoor evaporator unit110. The air conditioning system control board150is operatively connected to indoor evaporator unit110and the outdoor condenser unit170.

In one embodiment, physical wires are used to establish connection between the hardware processor140, the sensor130, and the air conditioning system control board150. The wires are also used to establish connection between the air conditioning system control board150, the indoor evaporator unit110, and the outdoor condenser unit170. In another embodiment, wireless communication establishes connection between the hardware processor140, the sensor130, and the air conditioning system control board150. Wireless communication is also used to establish connection between the air conditioning system control board150, the indoor evaporator unit110, and the outdoor condenser unit170.

In some embodiments, the sensor130measures temperature of the indoor evaporator unit110. The sensor130then transmits the temperature measurement in a form of a signal to the hardware processor140. The signal transmitted by the sensor130comprises at least one of voltage, current, resistance, or temperature. Once the hardware processor140receives the signal from the sensor130, it determines the temperature of the indoor evaporator unit110, and compares the temperature with a threshold value. If the temperature is greater or equal to the threshold value, then the hardware processor140waits for next signal from the sensor130. If the temperature is less than the threshold temperature value, then the hardware processor140switches off the air conditioning system100. In one embodiment, the threshold value is a value between 25 and 32 degrees Fahrenheit. In other embodiments, the threshold value comprises at least one of voltage, current, resistance, or temperature.

In one embodiment, the sensor130is a thermocouple. In other embodiments, the sensor130is either a resistor temperature detector (RTD) or a thermistor. In some embodiments, the sensor130is either a semiconductor or infrared (IR) sensor. The sensor130is a digital output temperature sensor in other embodiments. The sensor130will transmit different types of signals to the hardware processor140depending on what type of sensor the sensor130is. For example, RTD is a temperature sensor that measures changes in resistance as temperature changes. Therefore RTD sensor outputs resistance value that can be translated to a temperature value.

FIG. 2is a schematic diagram of another embodiment of an icing mitigation system for an air conditioner that can be similar in many respects to the embodiment illustrated inFIG. 1and include additional features as described hereinafter.FIG. 2illustrates an embodiment in which a hardware processor140is operatively connected to a memory160. The air conditioning system100can comprise an indoor evaporator unit110, an indoor evaporator coil120, an air conditioning system control board150, a thermostat155, an outdoor condenser unit170, and an outdoor condenser coil180. A sensor130can be installed on the indoor evaporator coil120.

In some embodiments, the sensor130is coupled to an inlet of the indoor evaporator coil120. In other embodiments, the sensor130is coupled to an outlet of the indoor evaporator coil120. The sensor130can also be coupled to any location on the indoor evaporator coil120that is between the inlet and the outlet of the indoor evaporator coil120.

The hardware processor140is operatively connected to the memory160, the sensor130, the air conditioning system control board150, and the thermostat155. The sensor130is operatively connected to the indoor evaporator coil120, which is operatively connected to the indoor evaporator unit110. The indoor evaporator unit110is operatively connected to the outdoor condenser unit170, which is operatively connected to the outdoor condenser coil180. Both the indoor evaporator unit110and the outdoor condenser unit170are operatively connected to the air conditioning system control board150so that they are able to communicate with the hardware processor140.

In some embodiments, the sensor130is installed at a point proximate to the indoor evaporator coil120. In other embodiments, the sensor130is installed inside the evaporator to measure the temperature of the refrigerant flowing inside the indoor evaporator coil120. In some embodiments, the sensor130is detachably installed on the indoor evaporator coil120, whereas in other embodiments, the sensor130is permanently fixed on the indoor evaporator coil120.

In some embodiments, the memory160of the hardware processor140is installed in a remote location. For example, the memory160may be installed in a separate compartment as the hardware processor140. In other embodiments, the memory160may comprise of a network of computing devices located in remote locations. The memory160can store information comprising predetermined threshold data and machine readable instructions that, when executed, cause the hardware processor140to collect temperature data from the sensor130, determine temperature of the indoor evaporator coil120from the temperature data, compare the temperature of the indoor evaporator coil120to the predetermined threshold data, determine that ice formation conditions are present when the temperature parameter of the indoor evaporator coil120is less than or equal to the threshold temperature value, and in response to determining that ice formation conditions are present, shut off the air conditioning system100. The method of operation of the ice mitigation system will be further described below.

FIG. 3illustrates another embodiment of an air conditioner with an icing mitigation system that can be similar in many aspects to the embodiments shown inFIGS. 1 and 2, and it can include additional features as described hereinafter.FIG. 3is an isometric view of internal components of another embodiment comprising the outdoor condenser unit170, the indoor evaporator unit110, the hardware processor140, air conditioning system control board150, and the thermostat155. The outdoor condenser unit170comprises a compressor310, the outdoor condenser coil180, and an outdoor condense fan320. The indoor evaporator unit110comprises an expansion valve330, the indoor evaporator coil120, an air intake duct345, a blower350, an air outtake duct355, and an air filter360.

In some embodiments, refrigerant flows from the indoor evaporator coil130to the compressor310. The compressor310then pressurizes the refrigerant and pushes it towards the outdoor condenser coil180. The outdoor condenser coil180transfers heat from the refrigerant to outside air. The outdoor condenser fan320creates airflow for the heat transfer. The outdoor condenser coil180is operatively connected to the expansion valve330to allow refrigerant to flow from the outdoor condenser valve180to the expansion valve330. The expansion valve depressurizes the refrigerant, which then flows towards the indoor evaporator coil120. The indoor evaporator coil120transfers heat from the refrigerant to inside air. The blower350generates airflow within the indoor condenser unit170. The air intake duct345allows inside air to enter the indoor condenser unit170, while the air outtake duct355allows inside air to exit the indoor condenser unit170. The hardware processor140is operatively connected to the air conditioning system control board150, the thermostat155, and the sensor130, which is operatively connected to the indoor evaporator coil120.

The sensor130can be installed at more than one locations. In some embodiments, the sensor130is installed at a point at which refrigerant enters the indoor evaporator coil120and another point at which refrigerant exits the indoor evaporator coil120. In other embodiments, the sensor130is installed at various locations between the points at which refrigerant enters and exits the indoor evaporator coil120.

The thermostat155can be a user interface device that comprises a display. The display of the user interface device can show temperature of a house or a building, along with a predetermined, configurable target temperature. The display can also display notifications generated by the hardware processor140. For example, when the temperature of the indoor evaporator coil120dips below a predetermined temperature, the hardware processor140can generate a notification signal, which prompts the display of the user interface device to display a notification. The notification can be in a form of a light. In some embodiments, the notification can be in a form of text or sound.

In some embodiments, the notification on the user interface device is temporary. The user interface can show a text-based notification for a predetermined duration. For example, the user interface device can display the notification for at least an hour. In another example, the user interface device can display the notification for duration of time between 10 minutes and 6 hours. In other embodiments, the notification can be displayed until additional input is provided. For example, the notification can be shown on the user interface device, prompting an input from a user. The notification can be displayed on the user interface device until an input from a user is received.

The user interface device can be located at various different locations. The user interface device can be located inside the air conditioning system. In some embodiments, the user interface can be located inside of a building in which the air conditioning system is installed. However, the user interface can also be located remotely. It is contemplated that the user interface device can also be a mobile device. For example, a mobile device can receive a notification signal from the hardware processor140of the air conditioning system wirelessly. The mobile device can be a mobile phone or a mobile computing device such as a tablet with wireless communication capabilities.

In some embodiments, a fan, instead of the blower350, generates airflow through the indoor evaporator unit110.

FIG. 4is a flow chart showing an example process for mitigating icing conditions in an air conditioner, such as, for example the air conditioner shown inFIG. 1, 2, or3. While a particular order of steps is disclosed, the steps can be arranged in other orders unless otherwise indicated. Steps can be removed or added at any point in the process without deviating from the scope of this disclosure. The process can begin at step200, at which the hardware processor140waits for a signal from the sensor130operatively connected to the indoor evaporator coil120. At step210, the hardware processor140receives a signal from the sensor130. At step220, the hardware processor140determines the temperature at the indoor evaporator coil120using the signal received from the sensor130. At step230, the hardware processor retrieves a temperature threshold value from the memory160. At step240, the hardware processor determines whether the temperature at the point on the indoor evaporator coil120is less than or equal to the temperature threshold value retrieved from the memory160. If the temperature at the point on the indoor evaporator coil120is greater than the threshold temperature value, the method goes back to the step200. If the temperature at the point on the indoor evaporator coil120is less than or equal to the threshold temperature value, the process then proceeds to step250, at which the hardware processor140determines that ice formation conditions are present. At step260, the hardware processor switches off the air conditioning system100.

In some embodiments, the sensor130collects temperature measurements continuously. In other embodiments, the sensor130collects temperature measurements intermittently. As known to those having ordinary skill in the art, the sensor130may collect temperature measurements at a regular interval. The temperature measurements can comprise at least one of voltage, current, resistance, or temperature.

In some embodiments, the hardware processor140determines the temperature at the indoor evaporator coil120by using a method comprising at least one of voltage-to-temperature conversion, current-to-temperature conversion, and resistance-to-temperature conversion. In other embodiments, the hardware processor140determines the temperature at the indoor evaporator coil120by using digital signal received from the sensor130. In some embodiments, the sensor130, instead of the hardware processor140, determines the temperature at the indoor evaporator coil120.

In other embodiments, the hardware processor140, instead of determining the temperature of the indoor evaporator coil120using the signal received from the sensor130, will instead directly compare the signal to the threshold value comprising at least one of voltage value, current value, or resistance value. For example, the hardware processor140receives a signal from the sensor130comprising a resistance value. Then the hardware processor140compares the resistance value from the signal to a threshold resistance value retrieved from the memory160to determine whether an ice formation condition is present. In some embodiments, ice formation condition is present when the resistance value from the signal is less than the threshold resistance value. In some embodiments, ice formation condition is present when the resistance value from the signal is greater than the threshold resistance value.

In some embodiments, the hardware processor140receives a signal from the sensor130comprising a voltage value. Then the hardware processor140compares the voltage value from the signal to a threshold voltage value retrieved from the memory160and determines whether an ice formation condition is present. In some embodiments, ice formation condition is present when the voltage value from the signal is less than the threshold voltage value. In some embodiments, ice formation condition is present when the voltage value from the signal is greater than the threshold voltage value.

In another embodiment, the hardware processor140receives a signal from the sensor130comprising a current value. Then the hardware processor140compares the current value from the signal to a threshold current value retrieved from the memory160and determines whether an ice formation condition is present. In some embodiments, ice formation condition is present when the current value from the signal is less than the threshold current value. In some embodiments, ice formation condition is present when the current value from the signal is greater than the threshold current value.

Other embodiments involve the hardware processor140generating a notification for a user interface when an ice formation condition is present. In other embodiments, there is a delay, with a configurable length, before the hardware processor generates the notification. Once the hardware processor140determines that an ice formation condition is present, it will generate the notification after a configured length of time has passed.

Other embodiments involve the hardware processor140terminating the air conditioning system100when an ice formation condition is present. In some embodiments, there is a delay, with a configurable length, before the hardware processor switches off the air conditioning system100. Once the hardware processor140determines that an ice formation condition is present, it will switch off the air conditioning system100after a configured length of time has passed.

In some embodiments, the hardware processor140terminates the air conditioning system100using a relay connected to a power source for the air conditioning system100. When the hardware processor140determines that an ice formation condition is present at the indoor evaporator coil120, the hardware processor140can trip the relay, disconnecting the air conditioning system100from the power source and turning the air conditioning system100off. The relay can be configured to have a first position and a second position, where the relay in the first position allows the air conditioning system100to receive power from the power source and the relay in the second position prevents the air conditioning system100from receiving power from the power source. The relay can be biased to the first position.

In some embodiments, the relay can be reset from the second position to the first position by user input. For example, the thermostat155or the user interface device, as described above, can generate a notification when an ice formation condition is present at the indoor evaporator coil120. The notification can prompt a user to reset the relay. The relay can be reset to allow the air conditioning system to receive power from the power source after receiving an input from a user.

FIG. 5is a flow chart showing an example process for installing an icing mitigation system in an air conditioner, such as the air conditioners disclosed with reference toFIG. 1, 2, or3. While a particular order of steps is disclosed, the steps can be arranged in other orders unless otherwise indicated. Steps can be removed or added at any point in the process without deviating from the scope of this disclosure. The process can begin at step400at which the sensor130is operatively connected to the indoor evaporator coil120. The process then proceeds to step410at which the hardware processor140is operatively connected to the sensor130. The process then proceeds to step420at which the hardware processor140is operatively connected to the air conditioning system control board150.

In some embodiments, the hardware processor140is installed separately from the air conditioning system control board150. In other embodiments, the hardware processor140is installed as a part of the air conditioning system control board150.

In some embodiments, the sensor130is a component of the hardware processor140. For example, the sensor130is installed as a part of the hardware processor140, and the hardware processor140is operatively connected to the indoor evaporator coil.

The various illustrative logical blocks, controllers, data structures, and processes described herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and states have been described above generally in terms of their functionality. However, while the various modules are illustrated separately, they may share some or all of the same underlying logic or code. Certain of the logical blocks, controllers, and processes described herein may instead be implemented monolithically.

The various illustrative logical blocks, modules, data structures, and processes described herein may be implemented or performed by a machine, such as a computer, a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a filed programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor may be a microprocessor, a controller, a microcontroller, a state machine, combinations of the same, or the like.

Depending on the embodiment, certain acts, events, or functions of any of the processes or algorithms described herein can be performed in a different sequence, may be added, merged, or left out altogether. Thus, in certain embodiments, not all described acts or events are necessary for the practice of the processes. Moreover, in certain embodiments, acts or events may be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or via multiple processors or processor cores, rather than sequentially.