Heating Assembly for Quick Heating of Occupied Spaces

This application claims the benefit of the filing date of provisional U.S. Patent Application No. 63/568,756 filed on Mar. 22, 2024.

This disclosure is directed to a heater assembly for supplementing the capacity of an existing heating network in specific locations within a structure such as an office building, an apartment building, or a warehouse.

Traditional thermal management systems utilized in large building spaces have conventionally consisted of burning oil, gas or coal. While effective in producing heat, these processes produce substantial amounts of Green House Gases (GHG), primarily in the form of Carbon Dioxide (CO2) as well as other pollutants. To reduce the amount of CO2, efforts have been made to utilize alternative approaches, in effect decarbonizing the heating process.

Additionally, the negative public perspective of the production of GHG's has rental ramifications. Landlords are increasingly having trouble renting out their floorspace in buildings perceived to produce substantial GHG. Buildings in New York City, for instance, are currently getting a rating from the Department of Buildings, largely influenced by energy efficiency. The A-buildings (greenest) are finding tenants, but the B and C buildings, mainly heated by gas or steam, are having difficulties. An option for owners is to make their facade better insulated, but that is a huge investment and prohibits income during the renovation.

Further, to avoid the production of GHG, landlords are transitioning away from combustion towards electrification for Heating Ventilation and Cooling (HVAC). One means to move heat from location to location is by heat pump. Heat pumps operate by Carnot cycle, that is, the changing of fluid phases between liquid and gas. Heat pumps, like most conventional HVAC systems, are centralized, so they tend to heat the entire facility, whereas only a small portion might require heat at any given time. This can be hugely wasteful. While effective, heat pumps have limitations at the extreme range of temperature, for instance, when it is very cold. By providing additional capacity, the heat pumps can be made to operate at the extremes. This additional capacity comes at a significant capital and maintenance expenditure, extending the Return on Investment (ROI) and acting as a disincentive for electrification. The cold extremes are limited in duration, however, comprising only a few days a year in some instances.

Accordingly, it would be advantageous to produce a heating system that could address the limited duration but very cold temperature excursions, without the economic disadvantages. It would be further advantageous to supply heat in a de-centralized manner so that heat is targeted only to specific locations, reducing the overall expenditure of energy.

Aspects of this disclosure are directed to a supplemental heating system to charge, store, and quickly release thermal energy into an occupied space or a space to be occupied. The system includes: an electric heater (e.g., an ohmic heater), a reservoir or buffer tank, a recirculation pump, an expansion tank, and an assortment of valves and plumbing to provide a recirculating hydraulic path. In some aspects of the disclosure, the system also includes a convector.

The system may operate in isolation, or may be tied into a heat pump, a heat pump network, or any hydronic heating system.

During a charge mode of the heating system, the recirculation pump operates to continuously circulate fluid through the electric heater and reservoir/buffer tank, with each pass of the fluid through the electric heater increasing the temperature (thermal energy) of the fluid. This charging process can operate at low power levels, keeping the electrical demand on the system low, which may take some time.

During a discharge mode of the system, the valve configuration is altered to allow the heated fluid to circulate through the reservoir and the convector. The convector quickly extracts heat from the heated fluid to increase the temperature of a target space, immediately prior to or after occupation. The target space may be an office, a residence, or other location that personnel will occupy.

Other aspects of the disclosure are directed to a heating system for localized heating of a space including an electric heater, a buffer tank, a convector, a recirculation pump, and a diverter valve. The electric heater has an inlet and an outlet and draws from 300 to 1500 watts. The expansion tank is coupled to the outlet of the electric heater, and the buffer tank has an inlet and an outlet. The convector has an inlet and an outlet, and the inlet of the convector is coupled to the outlet of the buffer tank. The diverter valve is coupled to the outlet of the buffer tank, and the diverter valve is actuable to direct fluid flow from the buffer tank to one of the convector or the recirculation pump. The heating system is operable in a charge mode and a discharge mode. In the charge mode, the diverter valve directs fluid flow from the buffer tank to the recirculation pump for recirculation through the electric heater, and in the discharge mode, the diverter valve directs fluid flow through the convector to heat a building space.

In aspects of the disclosure, the electric heater is an ohmic heater.

In some aspects of the disclosure, the buffer tank is integrally formed with the electric heater.

In certain aspects of the disclosure, the electric heater is a resistive heater.

In aspects of the disclosure, the convector forms a component of an existing heating network.

In some aspects of the disclosure, the electric heater and the convector are configured such that the charge mode is substantially longer than the discharge mode.

In certain aspects of the disclosure, the volume of the buffer tank is from about 2 liters to about 10 liters.

In aspects of the disclosure, the heating system includes a controller for activating the heater to maintain a set temperature within the heater assembly during the charge mode.

In some aspects of the disclosure, the controller controls actuation of the diverter valve to change operation of the heating system between the charge mode and the discharge mode.

Other aspects of the disclosure are directed to a method of supplementing an existing heating network with a heater assembly including providing the heating assembly with an electric heater for heating water, a buffer tank for storing the water, an expansion tank, a diverter valve, and a recirculation pump for recirculating the heated water through the electric heater and the buffer tank; connecting a fluid supply conduit of a convector of the existing heating network to an outlet of the buffer tank; connecting a fluid return conduit of the convector of the existing heating network to an inlet of the recirculation pump; and using the diverter valve to direct the heated water through a fluid circuit defined within the heating assembly to heat the water to a set temperature during a charge mode or directing the water to the convector of the existing heating network to supplement heat provided by the existing heating network to a building space to be heated during a discharge mode.

In aspects of the disclosure, the method further includes recirculating the water exiting the convector in the fluid return conduit back into the fluid circuit defined by the heater assembly during the discharge mode.

In some aspects of the disclosure, the method further includes closing a flow control valve in the fluid supply conduit to the convector and in the fluid return conduit from the convector prior to connecting the fluid supply conduit to the outlet of the buffer tank and prior to connecting the fluid return conduit to the recirculation pump.

In certain aspects of the disclosure, the method further includes securing a housing of the heater assembly to a wall defining the building space to be heated.

In aspects of the disclosure, the method further includes automatically initiating the charge mode based upon factors including a power utilities rate schedule and the occupancy schedule for the building space.

In some aspects of the disclosure, the method further includes integrating a controller of the heating system with building management system to optimize timing for initiating the charge mode.

In certain aspects of the disclosure, the method further includes isolating the fluidic circuit of the heating assembly from the existing heating network after the discharge mode.

In aspects of the disclosure, the method further includes initiating the discharge mode immediately prior to expected occupancy of the building space.

Although illustrative heating systems of this disclosure will be described in terms of specific aspects, it will be readily apparent to those skilled in this art that various modifications, rearrangements, and substitutions may be made without departing from the spirit of this disclosure.

For purposes of promoting an understanding of the principles of this disclosure, reference will now be made to exemplary aspects illustrated in the figures, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended. Any alterations and further modifications of this disclosure features illustrated herein, and any additional applications of the principles of this disclosure as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of this disclosure.

illustrates a localized heating system according to aspects of the disclosure shown generally as heating system. The heating systemincludes an electric heater, an expansion tank, a reservoir/buffer tank, and a convectorfor exchanging heat with a target space (e.g., liquid-to-air heat exchanger, such as a fan coil unit). The heating systemalso includes a recirculation pump, a three-way or diverter valve, and a network of pipes, and connectorsto provide a recirculating hydraulic path between the components of the heating system. In aspects of the disclosure, the outlet to the electric heateris connected by pipesto the expansion tankand to the inlet of the reservoir/buffer tank, and the outlet to the reservoir/buffer tankis connected to the convectorand to the inlet of the recirculation pump. The three-way or diverter valvecan be actuated to direct fluid flow to the convectoror to the inlet to the recirculation pump. This drawing is schematic and not necessarily to scale. The heating systemalso includes temperature and pressure sensors that facilitate control of the fluid temperature and pressure within the heating system. In aspects of the disclosure, the components of the heating systemexcluding the convectorare contained within a housing. Alternatively, the convectormay be positioned within the housing, and the housingmay include vent openings (not shown).

The electric heateroperates by directly heating the fluid, e.g., water flowing through the heater, specifically by directing electric current through the water itself so that the water is heated by conversion of electrical energy to heat within the water itself. In aspects of the disclosure, the electric heateris an ohmic heater structured so that water flows through a series of channels including or defined by electrodes selectively connectible to poles of a power source, so that current can be directed through various current paths extending through the water. The electrodes may be graphite electrodes, and the series of channels may be surrounded by a core. Examples of ohmic heaters that can be used in conjunction with the heating systeminclude those disclosed in U.S. Pat. Nos. 7,817,906, 8,861,943, 11,353,241, 10,365,013, U.S. Pat. Appl. Pub. No. 2022/0268140, and U.S. Pat. Appl. Pub. No. 2021/0153302, the entire contents of each of which are incorporated herein by reference.

The ohmic heatermay include several baffles extending axially, external to the heating core, and internal to an outside shell of the heater, where such baffles desirably provide additional reservoir volume. Although aspects of the heating systemdescribed here include a separate reservoir/buffer tank, it is envisioned that the ohmic heaterand the reservoir/buffer tankcould be integrated into a single unit having an expanded volume for containing an additional volume of water. In some aspects of the disclosure, the additional volume is defined between the baffles of the ohmic heater, so as to afford the required heating system volume within the ohmic heateritself. An example of such an ohmic heateris disclosed in the concurrently filed U.S. provisional application on even date herewith entitled Serpentine Recirculation Loop For Storage Of Heated Liquid and bearing Attorney Docket No. OHMIQ 3.8F-022, the entire disclosure of which is incorporated herein by reference.

In aspects of the disclosure, the reservoir/buffer tankmay be available off the shelf at minimal cost. Likewise, the convectormay be selected from one or more of a variety of commodity items readily and economically available. In some aspects of the disclosure, the convectormay be embodied by a fan coil unit, although the use of other types of convectors is envisioned. Further, the pipes, the three-way or diverter valveand the connectorsmay be selected from standard off-the-shelf items. In some aspects of the disclosure, the reservoir/buffer tank(or the electric heateritself) has a volume of between 2 and 10 liters. In certain aspects of the disclosure, the reservoir/buffer tankhas a volume of about 5 liters. However, the volume of the reservoir/buffer tankis selected to meet a desired capacity of the heating systemand as such may be outside of this range (larger or smaller).

The heating systemhas two modes of operation including a charge mode and a discharge mode. In the charge mode of operation, the heating systemis filled with water and the water is heated to steady state at a set high temperature of between about 95° C. and 105° C. During the charge mode, the three-way or diverter valveis actuated to allow water flow from the reservoir/buffer tankto the inlet of the recirculation pump, and water is forced by the recirculating pumpthrough the fluidic circulation path defined by the pipes, and the connectors. While the water is circulated through the heating system, the ohmic heaterheats the water directly on each pass of the water through the ohmic heaterwith the net effect of increasing the overall temperature of the water in the heating system. The water is continuously directed through the reservoir, then the three-way valve, and back to the recirculating pumpto raise the temperature of the water within the heating system. As the water is heated, the volume of the water expands and is taken up in the expansion tank. The charge mode of the heating systemis completed when the water is heated to the set steady state temperature. At this time, the heaterand the recirculating pumpcan be deactivated. If the temperature of the water within the heating systemdrops below the set steady state temperature, the heating systemcan be reactivated to recirculate the water back through the fluidic recirculation path and heat the water back to the set temperature.

The power required to charge the heating systemto a set steady state temperature is desirably low, e.g., 150 to 1500 Watts. In some aspects of the disclosure, the power required to charge the heating systemto a set steady state temperature is 300 to 1500 Watts. Accordingly, the charge mode may take a relatively long time, possibly several hours. The low power consumption allows installation of the heating systeminto existing low-power circuits in existing buildings without drawing significant capacity from that circuit.

When commanded or activated by a control system, possibly by the arrival of personnel on a particularly cold morning, the heating systemis designed to go into the discharge mode. In the discharge mode, the three-way valvediverts the flow of water from the reservoir/buffer tankto the convector, while still using the recirculation pump. Water exiting the convectoris directed by the pipesback to the inlet of the recirculation pumpand is recirculated though the fluidic circulation path until the no more or only a minimal amount of heat can be extracted from the water. At this point, the heating systemis deactivated or returned to the charge mode in which the three-way valvediverts water flow from the convectorback to the recirculation pump. Depending on the capacity of the convector, heat can be extracted from the heated water via the convectorand discharged very quickly into an occupied space or into a space to be occupied, possibly in minutes. It is envisioned that a heating assemblyhaving a reservoir/buffer tankhaving a 5-liter volume of fluid has the capacity to raise the temperature of a room 17 ft.×17 ft×10 ft from 55 C to 70 C in 3 to 5 minutes given reasonable estimates of air density, efficiency, and convector size. Once the discharge mode of the heating assemblyis completed, a typical building heating network() can be used to maintain the temperature within the occupied space at a comfortable level.

The heating systemcan be mounted in occupied spaces, or spaces to be occupied, to supplement an existing heating network such as a heating network having a heat pump or boiler. The heating assemblyprovides a quick and efficient means of adding capacity to the existing heat pump network at selected times of need and at specific locations of need without having to oversize the existing heating network.

illustrates an alternative version of the heating systemshown generally as heating systemthat may be incorporated directly into an existing heat network() in a building such as a network including heating unithaving a heat pump or an electric boiler. The heating systemis substantially like heating systembut does not include a convector. In contrast, the heating systemprovides heated fluid, e.g., water to a convector() of the existing heating networkto supplement the capacity of the existing heating networkin a particular location within the building.

The heating systemincludes an electric heater, an expansion tank, a reservoir/buffer tank, a three-way or diverter valve, a recirculation pump, and a network of pipes, valves, and connectorsto provide a recirculating hydraulic path between the components of the heating system. The components included in the heating systemare as described above regarding heating systemand will not be described in further detail herein. The heating systemincludes a couplingon the outlet pipefrom the reservoir/buffer tankand a couplingon the inlet pipeto the recirculation pump. The diverter valvecan be actuated to direct water flow from the reservoir/buffer tankto the inlet of the recirculation pumpor to direct water flow from the inlet pipeto the recirculation pump. In some aspects of the disclosure, the components of the heating systemare contained within a housingand the outlet pipeand the inlet pipeextend from the housingsuch that the couplingsandare positioned externally of the housingin a position to be coupled to an existing heating network.

illustrates a schematic diagram of a portion of a typical existing heating network. The heating networkincludes a fluid supply conduit, a convector, and a fluid return conduit. The fluid supply conduitdelivers a heated fluid to the convectorwhere heat is extracted from the hot fluid and delivered to an occupied space or a space to be occupied to heat the space. The cooled fluid exits the convectorand is returned to the heating networkthrough the fluid return conduit. The networkincludes an inlet flow control valvein the fluid supply conduitand an outlet flow control valvein the fluid return conduit.

The heating system() is configured to be incorporated into an existing heating network() to supplement the heating capacity of the heating networkat a specific location within a building as described above.illustrate a method according to aspects of the disclosure for supplementing the heating capacity of an existing heating networkat a specific location within a building. To incorporate the heating systeminto the existing heating network, the flow control valvesandare closed to isolate the convectorfrom the network, and power to the convectoris disconnected. The fluid supply conduitand the fluid return conduitare cut () and a valvehaving an actuatorand a T-fittingare installed into the fluid supply conduitupstream of the convector. In addition, a T-fittingis installed into the fluid return conduit(). Next, the outlet pipeof the heating systemis connected to the T-fittingin the fluid supply conduitof the network, and the inlet pipeof the heating systemis connected to the T-fittingof the fluid return conduitof the network.

The housing of the heating assemblymay be secured to a support structure of the building or structure near the convectorwithin the space to be heated using mounting brackets. For example, the mounting bracketscan be secured to studs in a wall or ceiling of the space to be heated.

Once the heating systemis incorporated into the existing heating network, the heating systemcan operate in the charge mode to heat the fluid within the heating system. In the charge mode, the valveis closed, and the diverter valvedirects fluid exiting the reservoir/buffer tankinto the recirculation pumpto recirculate the water through the electric heaterand the reservoir/buffer tankto be heated to the set temperature. When the set temperature within the heating systemis reached, the recirculation pumpand the electric heaterare deactivated. During this period, the heating networkcontinues to deliver heating fluid to the convector. When additional heating is needed in a location within the building in which the heating assemblyis mounted, the heating systemswitches to discharge mode to provide additional heat to the space in a fast and efficient manner. This switch from the charge mode to the discharge mode can be accomplished automatically with the controller described below. In the discharge mode, the valveis actuated to close fluid flow from the fluid supply conduitof the network, the valveis actuated to allow water to flow through the outlet pipe, and the diverter valveis actuated to direct flow from the reservoir/buffer tankinto the convectorof the networkvia outlet pipe, and direct return flow from the convectorinto the recirculation pumpvia inlet pipe. The recirculation pumprecirculates fluid from within the heating systemthrough the convectorto quickly heat the space.

After the heating systemhas completed the discharge mode, the valveis closed, the valveis opened to allow flow from the fluid supply conduitof the networkback into the convector, and the diverter valveis actuated to direct flow back to the recirculation pumpto recirculate the water though the heating assemblywhen the charge mode is initiated.

A heater system,in accordance with aspects of the disclosure depicted inmay include a printed circuit board assembly (PCBA) configured to receive electrical power and control signals and to distribute power to the electrodes within the heater,and to actuate the valves in the system. In aspects of the disclosure, rather than receiving control signals, the PCBA can include components that provide control functionality to provide power to the electrodes to operate the heater,, and to provide power to actuate the valves. This PCBA may include various electrical components, such as power management circuitry, sensing circuitry, relay or switching circuitry, one more controller(s), one or more memory, and/or communication circuitry, among other possible components.

In some aspects of the disclosure, the PCBA may include power management circuitry which manages voltage and/or current, such as AC/DC converters, step-up converters, step-down converters, and/or waveform shaping circuitry (e.g., pulse width modulation circuitry), among other possibilities.

In certain aspects of the disclosure, the PCBA may include sensing circuitry such as voltage sensors, current sensors, and/or circuitry that interfaces with sensors in the heater, such as circuitry that interfaces with temperature sensors in the heater, for example. The sensing circuitry may include, for example, amplifiers and/or analog-to-digital converters, among other possibilities.

In aspects of the disclosure, the PCBA may include relay or switching circuitry such as switches that connect and disconnect power to various of the electrodes of the heater. In other aspects of the disclosure, the relay or switching circuitry may include switches that connect to different electrical potentials from a power source. The relay or switching circuitry may include solid-state switches, among other possibilities.

In other aspects of the disclosure, the PCBA may include one or more controller(s), which may include any type of device that can provide control and/or computing functionality, such as microcontrollers, microprocessors, central processing units, and/or digital signal processors, among other possibilities. The controller(s) may include and may execute firmware instructions. In some aspects of the disclosure, the controller(s) may execute machine-readable instructions accessed from the one or more memories, which may include volatile memory (e.g., random access memory, etc.) and/or non-volatile memory (e.g., EEPROM, etc.). The machine-readable instructions may implement control functionality, such as controlling operations of the heater or the valves of the heater system,. The control functionality may connect power to various of the electrodes at various times according to a predetermined operation, and/or process sensing signals provided by the sensing circuitry to perform various computations and may connect power to various of the electrodes based on the computations. For example, the one or more controller(s) may operate to direct power to various of the electrodesin different cycles. As another example, the controller(s) may receive an input reflective of a set point temperature and receive sensing signals reflective of measured temperatures in the heater. The controller may direct or not direct power to various of the electrodes based on the set point temperature and the sensing signals reflective of the measured temperatures. Various other operations are described below herein. All such operations are contemplated to be within the scope of the present disclosure.

In certain aspects of the disclosure, the PCBA may include communication circuitry, such as wireless communication circuitry enabling communication using technologies such as Wi-Fi, Bluetooth, and/or cellular communications, among other wireless communication technologies. The communication circuitry may communicate with a user device, such as a smartphone, tablet, or other user device, and/or may transmit information to and/or receive information from a cloud system. The information communicated by the communication circuitry may be used in various ways, such as used by a user app to control operation of the heater assembly and/or to view performance of the heater assembly, or use to update firmware within the heater assembly, among other possibilities. Such and other aspects are contemplated to be within the scope of the present disclosure.