Patent Grant
10712021
Aspects of the disclosure relate to power modulating individual radiators, underfloor heating circuits, chilled beams or fan-coils for a heating/cooling system.
Traditional heating/cooling systems with hydronic emitters (including radiators, underfloor heating/cooling circuits, fan coils, chilled beams) often require substantial time (for example, six or more hours) to raise the room temperature even a few degrees C. One reason is that the flow temperature in underfloor heating (UFH) systems is typically quite low at around an average of 35 degrees C., and the flow rate is restricted to achieve a total circuit balance. The result is that the room cannot be placed in setback overnight. Consequently, in accordance with traditional approaches, a UFH system maintains a constant temperature in the room, for example 20-21 degrees C., because if the room were allowed to be lowered overnight the time taken for the room to get back to 20-21 degrees C. would take too long. In addition, various floor materials may have a maximum floor temperature that cannot be exceeded.
An aspect supports an underfloor heating (UFH) system that limits the floor temperature of an environmental entity (for example, a room) by pulsing (pulse modulating) the flow rate through a hydronic emitter (circuit) heating the environmental entity. Once the heated water fills the circuit, the flow is stopped for a fixed time before repeating the cycle. The ratio of flow/no flow (On/Off) may be a proportional lower floor temperature compared to a traditional circuit supporting a constant water flow. The net result is typically a lower floor temperature for the circuit that is pulsed on/off as opposed to a circuit that had a constant flow.
With another aspect, a UFH system may heat a plurality of rooms, each having different floor temperature limitations. The floor temperatures may be limited differently by pulsing the hydronic emitters (circuits) rooms differently.
With another aspect, a controller assembly adjusts the water flow through a hydronic emitter so that the room temperature approximately equals a targeted heating temperature without the floor temperature exceeding a maximum floor temperature. When the controller assembly receives a temperature set point and measured room temperature from an associated thermostat, the controller assembly adjusts the water flow so that the hydronic emitter fills with heated water. Once the controller assembly determines that the hydronic emitter is filled, the controller assembly causes a valve to close thus stopping the water flow during a determined time interval. Because water flow is turned on and then turned off during a cycle, water flow is pulsed. After one or more pulsing cycles, the controller assembly repeats the above actions based on the updated room temperature obtained from the associated thermostat. The controller assembly modulates (pulses) the water flow through the hydronic emitter until the room temperature reaches a targeted heating temperature.
With another aspect, a controller assembly detects when a hydronic emitter has filled with heated water when the measured outlet temperature sufficiently increases.
With another aspect, a controller assembly determines a ratio Ton/Toff from the maximum floor temperature. A hydronic emitter fills with heated water during Ton while water flow is shut off during Toff.
With another aspect, a manifold/valve heating/cooling system supports both a heating mode and a cooling mode. When in the heating mode, a controller assembly causes a hydronic emitter to fill with heated water and subsequently shuts off the water flow over a pulsing cycle. This is done in a repetitive manner until the targeted heating temperature is reached. When in the cooling mode, the controller assembly causes cooled water to flow through the hydronic emitter until the targeted cooling temperature is reached. The controller assembly then turns off the water flow.
With another aspect, a controller assembly supports a calibration mode, where a pulse ratio is determined from temperature measurements of a floor provided by a temperature sensor typically located on the floor. The controller assembly operates in an operational mode after completing calibration.
The foregoing summary of the invention, as well as the following detailed description of exemplary embodiments of the invention, is better understood when read in conjunction with the accompanying drawings, which are included by way of example, and not by way of limitation with regard to the claimed invention.
According to traditional approaches, the temperature of water flowing through an underfloor heating (UFH) system is quite low at around at average of 35 degrees C. The flow rate is typically restricted to achieve a total circuit balance, and the result is that a room cannot be placed in setback overnight. A traditional UFH system is typically controlled to a temperature between 20-21 degrees C. because if the room were allowed to be lowered overnight the time to restore the room temperature would be excessive.
To address the above deficiencies, the temperature of water flowing through a UFH system is increased with respect to traditional approaches. According to an aspect of the embodiments, an underfloor heating system limits the floor temperature of an environmental entity (for example, a room) by pulsing (pulse modulating) the flow rate through a hydronic emitter (circuit) heating the environmental entity. Without limiting the floor temperature, an occupant may experience discomfort when bare footed on a bathroom tiled floor and/or damage may occur with some types of floors. A room that requires a lower floor temperature may have its associated circuit filled with heated water. Once the heated water fills the circuit, the flow is stopped for a fixed time before allowing the cycle to repeat. The ratio of flow/no flow (Ton/Toff) may be a proportional lower floor temperature compared to a traditional circuit supporting a constant water flow. The net result is typically a lower floor temperature for the circuit that is pulsed on/off as opposed to a circuit that has a constant flow. Moreover, according to an aspect of the embodiments, a UFH system may heat a plurality of rooms, each having different floor temperature limitations. In such situations, the floor temperatures may be limited differently by pulsing the hydronic emitters (circuits) rooms differently.
Controller assembly 106 may support heating and/or cooling environmental systems. When supporting a heating mode, water flow pipe 107 transports heated water to hydronic emitter 101 through inlet 102. When supporting a cooling mode, water flow 107 transports cooled water. Water return pipe 108 returns the expended water from hydronic emitter 101 through outlet 103.
During the heating mode, controller assembly 106 adjusts the water flow through hydronic emitter 101 so that room temperature 151 approximately equals a targeted heating temperature (for example, set point 152 or the set point plus an offset) without the floor temperature exceeding maximum floor temperature 153. For example, when controller assembly 106 receives temperature set point 152 and room temperature 151 from an associated thermostat, controller assembly 106 adjusts the water flow though hydronic emitter 101 so that the hydronic emitter 101 fills with heated water. Once controller assembly 106 determines that the hydronic emitter 101 is filled (at the end of time interval Ton, for example, when the outlet temperature measured by sensor 104 is sufficiently high), controller assembly 106 causes the valve to close thus stopping the water flow during time interval Toff. Because water flow is turned on and then turned off during a cycle, water flow is pulsed. After one or more pulsing cycles, controller assembly 106 repeats the above actions based on the updated room temperature obtained from the associated thermostat. Controller assembly 106 modulates the water flow through hydronic emitter 101 until room temperature 151 reaches a targeted heating temperature.
With some embodiments, the maximum floor temperature may be obtained through the associated thermostat or from a wireless device via an app.
Controller assembly 106 may connect to temperature sensor 104 in a number of ways. For example, temperature sensor 104 may be a separate radio frequency module sensor that reports the measured temperatures to controller assembly 106 periodically or by a wired communication.
Controller assembly 106 obtains thermostat signal 251, which may be indicative of the temperature set point, current room temperature, and/or maximum floor temperature, via thermostat interface 204. With some embodiments, a UFH circuit must not exceed a maximum floor temperature. For example, an excessive floor temperature for a tiled floor of a bathroom may cause the occupant discomfort when bare footed. As another example, an excessive floor temperature may cause physical damage to floor material (for example, wood).
Controller assembly 106 may receive signal 251 through various communication media, including wireless or wired channels using different communication protocols.
Processor 201 processes signal 251 in accordance with computer readable instructions obtained from memory device 205. For example, the computer readable instructions may reflect flowchart 500 and/or flowchart 600 shown in in
Processor 201 also obtains measured temperatures measured at outlet 103 via temperature sensor interface 203 from temperature sensor 104. As will be discussed, microprocessor 201 may detect that hydronic emitter 101 has filled with heated water when the temperature at outlet 103 is sufficiently high.
With some embodiments, processor 201 determines a temperature difference between the room temperature and temperature set point extracted from signal 251. Processor 201 turns water flow on and off in a pulsed fashion by appropriating driving valve shaft 210 in order not to exceed a maximum floor temperature as will be discussed in further detail.
With reference to
Computer storage media may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media include, but is not limited to, random access memory (RAM), read only memory (ROM), electronically erasable programmable read only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by the computing device.
Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. Modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.
With some embodiments, memory devices 205 and 206 may be physically implemented with a single memory device.
Traditional approaches often have only a single thermostat and consequently do not support multiple thermostats. With traditional approaches, a boiler provides a single water temperature applicable to the entire building structure.
With an aspect of the embodiments, water flow is controlled separately for different hydronic emitters associated with different portions (for example, rooms) of the building structure (for example, a house) rather than at the boiler itself. Consequently, embodiments may support multiple heating/cooling zones.
Controller assemblies 301 and 302 control water flow through emitters 303 and 304, respectively, based on room temperatures, temperature set points, and maximum floor temperatures provided by thermostats 305 and 306, respectively. Consequently, controller assemblies 301 and 302 may support separate first and second heating/cooling zones, respectively. In accordance with some embodiments, while not explicitly shown, controller assembly 301 is electrically coupled to temperature sensors thermally coupled to outlet 308 while controller assembly 302 is electrically coupled to temperature sensors thermally coupled to outlet 310.
Emitters 303 and 304 may heat or cool different environmental entities (for example, rooms), where thermostats 305 and 306 are located in the corresponding environmental entities.
At block 402, when in the heating mode controller assembly 106 drives valve shaft 210 so that water flow (heated water) through the emitter is repetitively pulsed in order to prevent the floor temperature from reaching limits of the floor's material or to maintain the comfort level of the occupant. During each pulse, water flow is turned on during time duration Ton, and turned off during time duration Toff.
When in the cooling mode at block 403, controller assembly controls valve shaft 210 so that water flow (cooled water) through the emitter continues until a targeted cooling temperature is reached. The operation in the cooling mode may be different from that in the heating mode because cooling temperatures typically do not pose any damage to the floor material. Consequently, water flow may be pulsed in a single pulsing cycle.
With some UFH systems there are two temperatures that need to be controlled. One is the room temperature that is controlled via a room thermostat such that when the desired room temperature is reached that circuit is switched off. Conversely, when the room temperature is below the desired room temperature the circuit is switched on. The other temperature that may be controlled is the floor surface temperature.
With a traditional approach, some UFH room thermostats are fitted with two sensors, one for measuring the room temperature and the other for measuring the surface floor temperature. The floor temperature sensor may be a physical sensor which is connected to the floor surface or an infrared sensor mounted in the room thermostat that measures the floor surface temperature via an infrared sensor scanning the floor surface temperature below the thermostat. The purpose of the floor temperature sensor is to switch off the UFH circuit if the floor temperature is detected to be above the setting and conversely switch the circuit on when the surface temperature falls below the setting. The reason that floor temperature sensing is required, in addition to room temperature sensing, is that some floor surfaces within the home should not be allowed to become too hot, for example rooms that have laminate wooden floors or are installed with tiled floors. This “balance” between floor and room temperature control does present some problems. One deficiency with traditional approaches is that the floor sensing often takes place at the room edge, which is typically not the optimum place to sense the floor temperature. With infrared sensors the problem may be compounded. In addition to being near the room edge, the sensor must be unobscured between the thermostat and the floor surface. Traditionally, the flow temperature to the UFH system manifold is set to as low a flow temperature as possible to ensure floors do not become overheated; however, this approach may require that rooms take much longer than necessary to heat up.
With an aspect of the embodiments, varying the floor surface temperature in individual UFH circuit may result in higher flow temperatures with respect to traditional approaches.
With another aspect of the embodiments, controller assembly 106 provides a modulating control for HVAC emitters by start/stopping the fluid flow over a time cycle.
With another aspect of the embodiments, controller assembly 106 provides a variable floor temperature for underfloor heating by starting/stopping the flow over a duty on/off cycle.
Referring to
At block 502, controller 106 determines whether the room temperature is below a targeted heating temperature. If so, at least one pulsing pulse is generated at block 503, where water flow in turned on and then off. Pulsing may occur multiple times before controller 106 returns to block 501 to obtain the updated room temperature resulting from the pulsing.
As will be discussed, hydronic emitter (circuit) 101 may completely fill with heated water at the end of Ton before being turned off during Toff. However, with some embodiments hydronic emitter 101 may not completely fill with heated water during Ton. On the other hand, with some embodiments, hydronic emitter 101 may completely fill somewhere before the expiration of Ton.
With the some embodiments, the targeted heating temperature is equal to the set point temperature plus a temperature offset Δ. The temperature offset provides a hysteresis that prevents chattering around the temperature set point. Otherwise, when the ON/OFF control turns water flow on and off at the set point, there may be small amounts of noise near the set point, causing the water flow to turn on and off frequently,
At block 601, controller assembly 106 obtains a room temperature and temperature set point from the associated thermostat. At block 602, if the room temperature as measured at the thermostat is above a targeted cooling temperature, controller assembly 106 allows cooled water to flow through hydronic emitter 101. However, if the measured room temperature is below the targeted cooling temperature, the water flow is stopped at block 603.
While the floor temperature is typically not an issue to floor damage when cooling, the floor temperature may be uncomfortable to the occupant when the floor temperature is below a minimum floor temperature. If that is the case, controller assembly 106 may repetitively pulse water flow in a similar manner as when in the heating mode. However, the pulsing may be based on a cooling ratio Tcooling_on/Tcooling_off.
With some embodiments, water flow may be at a constant rate at block 603, either with the valve fully or partially open.
With some embodiments, water flow may vary. For example, at block 603 water flow may be reduced as the room temperature approaches the targeted cooling temperature.
During Ton, hydronic emitter 101 fills with heated water (with a water volume approximately equal to X % of full rate times Ton). This replaced amount of heated water may completely fill emitter 101. However, with some embodiments, this amount may partially fill emitter 101. During Toff, the heated water with in emitter 101 is allowed to transfer heat to the environmental entity before refilling during the next pulsing cycle.
Example 700 shows a constant water flow (X % of full rate) during Ton. However, water flow may vary during Ton by control assembly 106 changing the position of the valve during Ton.
As will be discussed, the pulsing cycle may be selected to that the resulting floor temperature does not exceed a maximum floor temperature that may damage the floor material of may be uncomfortable to an occupant when walking on the floor.
Relationship 800 may be determined by empirical or analytical means. For example, as will be discussed, a relationship between ratio Ton/Toff and the floor temperature may be empirically obtained from calibration mode 1001 (as shown in
With an aspect of the embodiments, a UFH system may support a higher flow temperature than traditional approaches, thus decreasing the time taken for a room to reach the correct room temperature while preventing some room floor surfaces from becoming too hot. Rather than allowing a constant flow of water through each UFH circuit, as occurs in traditional designs, the circuits that require a lower floor surface temperatures are allowed to completely fill with hot water. The flow is then shut off for a predetermined period of time.
Referring to
At block 903, controller assembly 106 determines Toff from the ratio corresponding to the maximum floor temperature of the floor material. For example, referring to
If the circuit is filled, controller assembly 106 quickly turns off the water flow at block 904. (Consequently, slow-acting actuators may require as much as three minutes to open or close and may be unsuitable with this approach.) The water flow remains off for Toff, which may be obtained from the ratio Ton/Toff corresponding to the desired maximum floor temperature as determined at block 903.
Controller assembly 106 may complete a number of pulsing cycles (one or more) before obtaining an updated room temperature at block 501 (as shown in
At block 1001, as will be discussed in further detail, controller assembly 106 determines a pulsing ratio corresponding to the maximum floor temperature of the room's floor. Controller assembly then uses the determined ratio when operating in the operational mode at block 1002 as previously discussed with
During the calibration mode, the floor temperature may be measured by a thermometer temporarily placed on an appropriate floor location (for example, the middle of the floor) to obtain a representative measurement of the floor. The thermometer may communicate with controller assembly 106 through different communication means (including wireless or wired means) or may communicate with controller assembly 106 via an associated thermostat (for example, thermostat 305 as shown in
Referring to
Based on calibration process 1100, controller assembly 106 obtains an appropriate ratio value that can be used during the operational mode in order to keep the floor temperature from reaching the maximum floor temperature. However, with some embodiments, controller assembly 106 may construct a floor temperature-pulsing ratio relationship (for example, relationship 800 as shown in
As can be appreciated by one skilled in the art, a computer system with an associated computer-readable medium containing instructions for controlling the computer system can be utilized to implement the exemplary embodiments that are disclosed herein. The computer system may include at least one computer such as a microprocessor, digital signal processor, and associated peripheral electronic circuitry.
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