Patent Application
20230366563
The present invention relates generally to heating, ventilation, and air conditioning (HVAC) systems and more particularly, to chilled beam HVAC units that incorporate fans to provide temperature management with as little primary airflow as possible.
Chilled beams HVAC systems are either active systems that include an integrated air supply or passive systems that do not. Unsurprisingly, the integration of an air supply and the generated induction in active systems allows active chilled beam (ACB) systems to provide a greater cooling capacity than a passive chilled beam unit. Given their greater cooling capacity, ACBs are desirable for use in a variety of settings including both “ventilation-driven” and “cooling-driven” applications.
Ventilation-driven applications include spaces with high ventilation requirements and/or high latent load density relative to sensible loads such as classrooms, laboratories, patient rooms, etc. In ventilation-driven applications, the primary airflow provided to the ACB is determined by ventilation or latent requirements, rather than by sensible cooling. Active chilled beam units generally have excellent energy efficiency in such applications as there is significant primary airflow provided.
In contrast, cooling-driven applications include spaces with low ventilation requirements and low latent loads relative to sensible loads, such as, for example, office spaces. Known active chilled beams are not well suited for cooling-driven applications, however, as ACBs provide a cooling capacity that is proportional to the primary airflow the ACB receives. As cooling-driven settings typically require and include a relatively low amount of primary airflow, ACBs can only provide a limited amount of cooling in such settings. It is therefore challenging to design ACB systems to meet sensible cooling loads using the typical minimum air flow standards, i.e., the greater of 1) the minimum airflow to satisfy code ventilation requirements; or 2) the minimum to satisfy space latent loads.
Therefore, a need exists a chilled beam unit that can accommodate low primary airflow provided in, for example, cooling-driven applications such as office spaces.
With the forgoing concerns and needs in mind, it is the general object of the present invention to provide a chilled beam unit that can accommodate low primary airflow.
In an embodiment, a chilled beam unit includes a manifold having at least one induction aperture and at least one discharge slot, said induction aperture enabling a passage of air into the chilled beam unit from a space below the chilled beam unit and the discharge slot enabling a passage of air out of the chilled beam unit. The chilled beam unit also includes at least one fan mounted within said manifold about the induction aperture and configured to induce a flow of air from the space below the chilled beam unit into said chilled beam unit through the induction aperture. The chilled beam unit further including a heat exchanger mounted within the manifold on an upstream side of the array of fans and configured to accept a flow of air therethrough.
These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:
Reference will be made below in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference characters used throughout the drawings refer to the same or like parts, without duplicative description.
As used herein, the terms “substantially,” “generally,” and “about” indicate conditions within reasonably achievable manufacturing and assembly tolerances, relative to ideal desired conditions suitable for achieving the functional purpose of a component or assembly. As also used herein, the terms “upstream” and “downstream,” describe the position of the referenced elements with respect to a flow path of a fluid flowing between and/or near the referenced elements.
While embodiments disclosed herein are described with respect to use in cooling-driven applications, i.e., spaces with low ventilation requirements and low latent loads relative to sensible loads, such as office spaces, it is to be understood that embodiments of the invention may be applicable other settings and applications where there is little, reduced, or no primary airflow. In embodiments, inventive chilled beam units can be combined with traditional ACBs or other types of heating / cooling systems, e.g., baseboard and forced air.
As will be appreciated, embodiments of the inventive unit 10 and system are configured for ceiling installation. As such, the housing 25 may be recessed in a suspending ceiling with the discharge slots 24 and the induction aperture 22 facing substantially downward into the space. In this regard, the unit 10 may be sized and shaped to fit into a conventional suspended ceiling grid.
The array of fans 30 require minimal electricity for operation. In one embodiment, each fan runs on 12 volts of direct current electricity and consumes approximately 1.2 watts of power. In certain embodiments, an eight-foot-long chilled beam unit 10 has an array of twenty fans, resulting in about 24 watts of power consumption. As a result, the power consumption of the array of fans 30 is very low (similar to an LED light fixture). In the embodiment depicted in
In embodiments, a temperature sensor is mounted to the heat exchanger 40. In particular, the units 10 and system may utilize factory mounted sensors located on a tube of the coil of the heat exchanger 40. The sensor measures the temperature of the coil. In one embodiment, there are two temperature sensors, a first sensor that turns the fans on if the coil is cold, and a second sensor that turns the fans on if the coil is hot. As will be appreciated, the array of fans 30 are configured to induce the flow of air through the induction aperture 22 in response to the temperature measured by the sensor(s). In one embodiment, the array of fans 30 induce the flow of air through the induction aperture 22 if the sensor measures a temperature that is less than or greater than a threshold value. Each chilled beam unit 10 is configured as cooling only, heating only, or cooling and heating. The chilled beam units that are configured as cooling only and heating only switch on the array of fans 30 when the sensor measures a single temperature threshold value. Chilled beam units configured as cooling and heating switch on the array of fans 30 when the sensor measures one of two temperature threshold values. As will be appreciated, while described as located on a tube of the heat exchanger, the sensor(s) may be in a variety of locations within the chilled beam unit 10.
In embodiments, chilled beam units 10 are combined with conventional ACBs and the resulting overall system utilizes the control logic that is already programmed into the zone controller that controls the valve used to control water flow to the ACBs.
The sound level or sound generated by chilled beam units is an integral factor in choosing the appropriate unit for the application. One embodiment of the chilled beam unit 10 generated a sound level of approximately NC32. A maximum sound level of NC40 is the typical target for open office HVAC systems. As a result, the sound level of the chilled beam unit 10 is suitable for most office spaces.
The chilled beam unit 10 disclosed herein is compatible with assemblies incorporating active chilled beam units that require connections to primary air sources. In some embodiments, units 10 are combined with conventional ACBs or other chilled beams systems. Here, the same water coils may be used for both. In particular, water coils / heat exchangers 40 may be piped in parallel with the heat exchangers of the other chilled beam units in the same zone and may be served by the same water control valves. In such systems, ACBs may represent a relatively small percentage of chilled beams in the overall system, e.g., 25%, depending on various design factors, e.g., additional sensible cooling requirements.
In one embodiment, the chilled beam unit 10 has the same (or lower) overall height of a prior art chilled beam unit (e.g., an “ACB40” chilled beam), the same mounting brackets, and the same appearance.
In another embodiment, an array of fans may be added or retrofitted to a conventional passive chilled beam unit or other chilled beam.
In certain embodiments, a controller (not shown) may be utilized for each unit 10. The controller could include one or more switches in communication with the sensors on the heat exchangers. For example, the controller may include a heating temperature switch and a cooling temperature switch. The switches in turn, may be in communication with the fans. The controller may also include a 24VAC to 12VDC converter. In embodiments, USB splitters may be employed to power the array of fans, though other solutions, e.g., a linear PCB, are certainly possible.
Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.
This application claims the benefit of U.S. Provisional Application Serial No. 63/341,222, filed on May 12, 2022, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63341222 | May 2022 | US |
