Patent Grant
9945620
The present invention relates to a radiator for building heating and cooling, more specifically to a fluid media radiator designed for installation adjacent to a building window. It offers dramatic improvements in energy efficiency and appearance, and because of its location and lower temperature differential radiation, increases the usage of room perimeter space. The design has mechanical expansion tolerance resulting in protection from damage to the radiator caused by fluid freezing. The overarching concept is for the thermal losses or gains at the perimeter of a building (generally at the windows) to be addressed directly at their source, allowing the central heating and cooling systems to be dramatically downsized while incorporating freeze damage protection for the radiator.
Perimeter room heating is well known in such systems as hot water radiators, electric registers, and forced hot air systems. However, this is not the case for the cooling systems. Generally these ventilate cold air (not a fluid) through a centralized room location.
Radiators provide a combination of radiation and convection of thermal energy. These all suffer common drawbacks in that they occupy space at the floor-wall interface, and require additional room between adjacent furnishings to operate safely or at full efficiency. Additionally, they are located at some distance from the most common source of thermal loss (both hot and cold egress)—the windows. Thus, most require extreme differences between the heat transfer media (fluid or gas) and the ambient air for adequate thermal energy transfer. Since the driving force for the transfer of energy from the room heating/cooling system is a function of the differential between the surrounding air and the thermal source the most efficient system should be located as close as possible to the heat transfer ingress/egress source in the room. That would be the windows. Existing systems are near but not adjacent the windows. The present invention locates the heat transfer media at the window. In this way a lower temperature differential in the heat/cool transfer media (preferably water) located closer to the window can maintain the average room temperature as well as emit as much energy into a room as would a higher temperature differential source located further from the window.
A further problem with the prior art radiators, especially those that use water as the fluid heat transfer medium, is that in the event of an uncompensated cold ingress, the fluid heat transfer media can freeze, bursting the shell of the radiator or damaging any of the components contained therein the shell, and leading to disastrous flooding, or reduced efficiency.
This new design and physical relocation allows the present invention to be designed for application with moderate heat transfer media temperatures thus enabling much more efficient heating/cooling systems to be installed through the use of heat pumps, heat recovery, geothermal heat pump, solar hot water, geothermal hot water, ground source heat pump, and exhaust air energy recovery coupled with water-to-water heat pump.
Henceforth, the architecturally and thermally improved perimeter radiator fulfills a long felt need in the building heating/cooling industry. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems and accomplish this.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new heating/cooling radiator that is able to maximize room perimeter usage and provide a level of efficiency with lower energy cost compared to existing, higher differential temperature heating/cooling systems. It has many of the advantages mentioned heretofore and many novel features that result in a new radiator which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art, either alone or in any combination thereof.
In accordance with the invention, an object of the present invention is to provide an improved room perimeter radiator that is capable of providing a thermal barrier between occupant and window energy loss/gain.
It is another object of the present invention to provide a radiator that is designed for cross fluid connection to another identical radiator and that can withstand freezing of either of its fluids.
It is another object of the present invention to provide a radiator with the ability to compensate for the increase in volume of a contained fluid (such as freezing water) by mechanical expansion, therein preventing freeze damage to the radiator.
It is another object of the present invention to utilize an air to radiator heat transfer surface giving a high coefficient of heat transfer accomplished by a thin walled highly thermal conductive outer casing surrounding a spiral chambered vessel that increases the effectiveness across the heat transfer surface.
It is another object of the present invention to provide a radiator with an internal conduit that can freely pass through yet prevent a spiral insert that resides between the conduit's exterior and the interior of the heat transfer shell from deformation caused by the flow of the heat transfer fluid medium.
It is another object of the present invention for the spiral insert and conduit to be constructed of an elastically deformable material to provide freeze damage protection.
It is also a further object of the present invention to provide a radiator that can be coupled to an identical radiator with a cross connection of their heat transfer fluid medium and freeze damage resistant fluid medium, so that cross connection between the two can be enabled to increase the efficiency of the overall efficiency of the connected radiator pair.
It is another object of this invention to provide an improved radiator capable of cooling or heating a room by the transfer of thermal energy from or to a low pressure fluid medium.
It is a further object of this invention to provide a room perimeter heating/cooling radiator that is easily installed, compatible with a vast array of heating and cooling systems, and inexpensive to manufacture and has is resistant to damage cause by the freezing of the heat transfer fluid medium.
It is still a further object of this invention to provide for a room heating/cooling system that improves space comfort by minimizing temperature gradient within a room.
In the small part of the bearing there is a hole that accepts a nut.
It is yet a further object of this invention to provide a room perimeter radiator which will not hamper the placement of room furniture.
The new radiators utilize clean linear appearance with an internally enhanced primary only, heat transfer surface. These radiators have no unsightly exterior fins and avoid the unattractive, bulky look. The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. Other objects, features and aspects of the present invention are discussed in greater detail below.
The above description will enable any person skilled in the art to make and use this invention. It also sets forth the best modes for carrying out this invention. There are numerous variations and modifications thereof that will also remain readily apparent to others skilled in the art, now that the general principles of the present invention have been disclosed.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
A “radiator” is type of heat exchanger wherein the energy (heat) transfer occurs at the exterior surface of the radiator and most commonly, the energy transfer medium external to the radiator is air.
A “rounded” configuration herein means a transverse cross sectional shape that is not circular, but rather forms a non symmetrical ellipse, including a “D” having two corners.
It is to be noted that the present invention is directed to use with water or a water/glycol mixture for the heat (energy) transfer first fluid as well as the freeze damage protection second fluid. These expand minimally from the density of their liquid phases when they freeze. Although it can be used with other mediums including those in a gaseous state, its freeze protection feature is lost with mediums that do not experience expansion in their solid state.
The present invention sets out a novel design wherein a radiant heat exchanger, transferring energy between the surrounding air and a heat (energy) transfer first fluid through the thin wall of a thermally conductive radiator shell, has an internal, mechanical freeze damage protection system, that incorporates a freeze damage protectant second fluid, a gas or elastically deformable foam, jell or similar medium, housed in an elastically deformable core tube (thermally insulated from the heat transfer fluid) as well as an elastically deformable free floating baffle housed between the radiator shell and the core tube. The design of the radiator allows for the coupling of two identical radiators and the cross connection of their first and second fluids to increase their overall heat transfer efficiency per unit length.
It is to be noted that the radiator is not “freeze proof.” However, the radiator can undergo several freeze and thaw cycles without any mechanical damage to the radiator and its components. When the amount of heat energy transferred out of the volume of first fluid contained in the radiator shell causes the temperature of the first fluid in the radiator shell (water or a water based fluid in the preferred embodiment) to drop below its freezing point, the first fluid will freeze solid and the radiator can be said to have “frozen.” When the radiator freezes if the first fluid is water, the volume of the first fluid trapped within the radiator shell will expand approximately by 7%, bursting any round shell, partially detaching the radiator caps or fittings and/or deforming the baffle. It is not the act of freezing that the present device protects against. (There is negligible heat transfer between the second fluid and the first fluid as the core tube is thermally insulated.) Rather, the design and material selection of the baffle, the core tube and the radiator shell is such that they have enough elastic and non-elastic deformation, alone or combined, to accommodate this 7% increase in volume.
The mechanical expansion is accomplished by either or both of the core tube and the shell. The core tube elastically deforms or “crush” inward and accommodates some or all the extra volume for the expanding, frozen first fluid, thus minimizing the extra force exerted onto the radiator shell. Inside this core tube is a non frozen fluid (air, foam or jell) which can move to accommodate the reduction in the internal size of the core tube. The transverse cross sectional shape of the radiator shell is rounded but not circular. A shell with a circular transverse cross section cannot tolerate internal expansion because all the expansion forces are applied evenly to the inner surface attempting to expand the shell at every point. This results in a burst failure at the weakest point of the shell. The rounded shell (which has a non symmetrical ellipse or a D transverse cross sectional shape) being of a non symmetrical shape sees more pressure at different regions and thus non-elastically deforms in the region seeing the greatest pressure by bulging outward slightly. Without the full pressure caused by the freezing water being exerted at the weakest point of the shell, and deformation outward reducing the internal pressure, a shell failure is avoided mechanically.
The spiral fin of the baffle may be bent out of its helical configuration as the first fluid freezes, but because of its ability for elastic deformation, it will return to its original shape when the first fluid thaws, thus allowing the flow pattern of the first fluid to remain unhampered. Thus, this apparatus does not prevent or hamper freezing, but just prevents the freezing first fluid from damaging the radiator and its internal components. In a similar fashion, if the freeze damage protectant second fluid freezes, the core tube may bulge outward rather than splitting along its length or exerting pressure at its connection to the radiator end caps until they fail. Here again, freezing of the radiator can occur. Either of its first and second fluids can freeze without damage to the radiator. Hence the term “freeze damage resistant” radiator rather than “freeze proof” radiator or “freeze protected” radiator.
While existing prior art focuses on freeze protection through the application of internal or external heat to the heat transfer medium, the present invention provides a mechanical (rather than thermal) means of freeze damage protection. Simply stated, the core tube can elastically deform and alter its shape to accommodate some or all of the freezing volume changes within said first or second fluid chambers, and the shell itself can non-elastically deform to absorb the remainder of the freezing volume change if need be.
In the prior art there are heat exchangers/radiators that upon first view appear, other than the non circular transverse cross section, to be structurally similar to the present invention. They consist of circular transverse cross sectional shells or housings capable of accommodating the flow of a first fluid within a first chamber of the shell, and the flow of a second fluid within a second chamber of the shell (separated by a fluid proof barrier) and a fin disposed therein the first chamber. Such an example is the heat exchanger means of Haag U.S. Pat. No. 2,060,936. Generally these are circular in transverse cross section for ease of fabrication. The difference between these prior art devices is that their designs function around the transfer of thermal energy between the first and second fluids. They accomplish this using thermally conductive barrier materials between the two fluids (such as a thin walled metal pipe), and fins in contact with the surface of the barrier (either directly or with a backbone sleeve that snugly fits into contact over the barrier) to increase the surface are of heat transfer. The present device eliminates any thermal transfer between the fluids. The material chosen for the barrier and its thickness is selected to eliminate heat transfer. The fin therein is not in contact with the barrier of the shell, and exists to create turbulent flow within the first chamber not to aid in dissipating heat. To accommodate this, it utilizes a thermal energy transfer barrier (thermally insulated core tube) and an elastically deformable barrier. Generally this is a thick walled polymer tube. This allows the present device to withstand multiple freeze and thaw cycles of either of the fluids. Thus while at first blush the prior art appears to be structurally equivalent to the present invention, they are not. They are designed with different goals in mind, they cannot undergo freeing without structural damage, and they teach away from what the present invention seeks to accomplish.
The present invention relates to a heating/cooling radiator that dissipates or absorbs thermal energy via a heat transfer first fluid through a thin walled, finless shell of highly thermally conductive material. It is designed for the transfer of energy only between the radiator's first fluid and the surrounding air. It has a central linear core tube for the passage of a freeze protection damage second fluid (optionally air, foam or gel) at a different temperature than the first fluid. It is preferably mounted near the source of the energy surplus or deficit, like a perimeter wall window. It has an internal helix baffle that has a central linear bore that allows it to reside inside and unconstrained, about the freeze damage resistant core tube. In the event that enough energy is dissipated from the energy transfer media in the shell to the surrounding air to cause the media to freeze, the warmer fluid in the insulated core tube 6 will remain in the liquid state such that the core tube 6 can elastically deform so as to accommodate some or all of the additional volume of the freezing media in the shell without splitting the shell. The core tube 6 may also be of a rounded transverse cross sectional configuration, This shape allows the core tube to deform with less pressure that would be required if the core tube 6 had a circular transverse cross section.
The rounded shell allows for expansion deformation in specific designed regions to accommodate the remaining uncompensated for volume increase. as well (It is known that both the first and/or second fluid may be replaced with gasses as well.) For example in the configuration of a D with two squared corners the planer region bounded by the corners will deform first, bulging outward.
The internal helix baffle maintains turbulent rather than laminar flow throughout the shell to maximize media energy transfer with the shell. It is designed to be located adjacent to windows which are the source of entry for heat or cold into the building. In this way temperature compensation can be made closest to the need. This prevents large variances in room temperature and allows for heat/cold to be input to the room at a point where there exists the greatest temperature differential with the surrounding air. This large differential accommodates such a high efficiency of heat transfer, that a lower temperature heat transfer media (generally water) can accomplish what heretofore required much hotter media.
In the event of a failure of the heat source for the heat transfer fluid, the inner core tube has the ability to elastically deform (crushing inward or bulging outward) to accommodate the expansion of freezing fluid whether in the core tube 6 first or the shell 8 first.
While this present invention is designed for use with heat pumps, geothermal hot water, geothermal heat pumps, natural gas heated water and electrically heated water systems, the ability to use solar heated water is not precluded. The moderate water temperatures and moderate surface temperature shall allow furniture to be placed in extreme close proximity to the radiator.
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Although discussed in non-symmetrical elliptical transverse cross sectional configuration, the radiator shell, core tube and baffle may also be “D” shaped. The advantage of this “D” shape is that additional freeze damage protection is inherent in the configuration as there is more room for elastic deformation in the flat sides of the shell and the core tube.
For the freeze damage protection to work, this requires that there is a small gap 99 between the baffle 12 and the core tube 6 to accommodate the changes in the core tube's diameter and shape when freeze damage protection occurs. The baffles are matingly conformed to the geometry of the tubular shell in which they reside. The helical configuration of the baffles impart an internal spiral of fluid circulation (turbulent flow) around the inside of the shell. The dimensional tolerances of the helix baffle are such that the vast majority of the heat transfer first fluid must undergo this turbulent flow as it traverses along the length of the shell.
The core tube 6 may be made of polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC) or copper pipe, as these have adequate thermal insulating properties when utilized in an appropriate wall thickness, however in the preferred embodiment it is fabricated from a cross-linked high density polyethylene (HDPE). The baffles 12 in the preferred embodiment are also made from the same material as the core tube 6 so as to enable elastic deformation as discussed herein. The core tube is thermally insulated so as to minimize energy transfer between the fluid in the shell and the fluid in the core tube. This is a critical feature not found in the prior heat exchanger or radiator designs. The prior art heat exchangers are designed for the transfer of energy between the two separated fluids within the heat exchanger. Hence, any fin must be in direct contact with the surface of the heat transfer surface to increase the transfer of heat energy. In this present design, energy transfer between the middle fluid and the core is not sought and is counter productive. Simply stated, it defeats the purpose of the apparatus. The freeze damage protection is lost if heat transfer between the first fluid and the second fluid can occur. In this apparatus, the second fluid exists for two purposes. First, to enable freeze damage protection, and second, in specific configurations involving connected heat exchangers with two fluids flowing therein, to increase the linear efficiency of the energy transfer for the conjoined radiators. This is accomplished through cross connection of the first and second fluids (as explained and shown in
Generally, the wall thickness of a pipe or tubing is determined by the operating pressures of the media therein. Since the present invention is designed to operated at low pressures, the normal convention would be to use thin walled material for the core tube. However, to accomplish the thermal insulation, thick walled tubing would be required. Although it is specified in the preferred embodiment (with the preferred embodiment operating temperature range listed above) that the wall thickness would lie in the range of 10 to 13% of the tube diameter, this ratio varies based on a function of the temperature differential across the thermal barrier (core tube), and as a rule of thumb, can best be approximated as a minimum schedule 80 wall thickness in the temperature.
Although the high density polyethylene core tube wall thickness disclosed herein is suitable to provide the level of thermal insulation for window perimeter uses, it is also know that for other thermal energy transfer media and for operation at elevated pressures and temperatures, an additional insulation around the core tube 6 may be necessary.
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When the radiators are located at a distance from the source of heat loss or heat ingress, the temperature gradient across the primary heat transfer surface (the outer wall of the radiator shell) is reduced and the efficiency is reduced. Using medium temperature water in the 90 to 130 degree F. range, may require the coupling of two or more radiators in such locations.
The heat transfer boundary in the radiator is at the outer surface of the shell. Compared to the prior art radiators, the surface area of the transfer boundary is larger and the log mean temperature difference at the second cross flow connected radiator jumps up (increases) back to what it was at the inlet to the first radiator. In the prior art radiators, the amount of thermal energy that is transferred per unit length of travel continues to decrease. In the preferred embodiment system, this occurs only to the midpoint of the series, cross flow connected radiators where the separate radiators are cross connected. Here the amount of energy that is transferred per unit length of travel rises to the same value it had at the inlet to the first radiator. Looking again at
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The new and novel concept of this radiator is best explained in terms of it's energy impact. From thermodynamics it is known that heat transfer energy=heat transfer coefficient*surface area*temperature difference.
Energy transfer is improved in two ways. First in an improved heat transfer coefficient of thin walled extruded tube resulting from increased transfer of energy by spiraling the fluid against the inside wall, thereby extending the fluid path and simultaneously agitating the fluid. Second, heat transfer is improved by increasing the temperature difference over conventional radiators by locating the radiator directly adjacent and at the window side or sil where the largest temperature difference between the ambient air temperature and the radiator heat transfer surface exists. Currently heating radiators are usually placed in a baseboard location and radiant cooling panels are ceiling mounted. By locating the air conditioning device closer to the energy gain/loss source, the window, a greater temperature differential is achieved.
The result of this invention, combined with recent improvements in windows construction, now allow the improved radiator to satisfy all the window energy gain or loss. This results in a new HVAC airside system which provides significant fan, reheat and thermal energy savings. Fan energy is reduced because perimeter space airflow is lowered from about 2 CFM/SqFt down to 0.5 CFM/SqFt in well constructed buildings. This 75 percent reduction in airflow, translates into 75 percent reduction in perimeter served fan energy. Reheat energy is minimized as supply airflow is no longer reheated in the supply duct. Traditionally VAV terminals have minimum airflow of 0.4 CFM/SqFt in order to have adequate diffuser velocity so ceiling grille supplied warm air will get to the floor. With radiant heat, the minimum airflow is generally reduced down to 0.06 CFM/SqFt (plus 5 CFM per person) in most spaces. The third energy benefit is thermal energy advantage on spring and fall days. In mild weather, it is common for shaded windows to have energy loss, while sunny windows are having energy gain. Using a water-to-water heat pump, in combination with changeover valves at the radiators, the radiator's in cooling will offset the radiator's in heating providing outstanding energy savings. Using whole building computer energy analysis, a high efficiency 10,000 SqFt office building in Portland Oreg. would experience 29.9% reduction in fan energy, a 12.2% reduction in thermal (heat/cool) energy resulting from using radiant rather than reheat system, and the overall thermal energy savings is 26.8% when using improved radiators, water-to-water heat pumps and changeover valves.
To describe conduit application, typically a window is 3 to 5 feet wide and would be served by a pair of radiators, one mounted low to induce warming updraft against cold window, one mounted high to induce cooling downdraft against warm or sunny window. With this application the conduit is normally utilized for returning “spent” water in order that supply and return are at same end of the radiators. The pair of radiators serving a window could be installed in either series or parallel depending on window height and the capacity need of the window.
On larger windows 5 to 10 feet wide, traditional radiators have a diminished capacity. The improved radiator can be installed with a cross connection at the center, with the conduit utilized as a secondary supply path. This will provide capacity and efficiency of having two radiators installed end to end, but with each radiator piped in parallel, thereby increasing the overall capacity and efficiency.
It is known that the radiator shell may be constructed from a plethora of materials that meet the requirements of a high coefficient of heat transfer and thin wall economical construction such as aluminum, copper or other formed metals and plastics. The radiators of the present invention are intended to minimize space impact and have appearance matching traditional and contemporary building trim. While prime usage shall be mounting in close proximity to windows, a family of products including baseboard and pedestal models can incorporate the same solution concepts.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The following application incorporates by reference and is a continuation in part (CIP) of the CIP U.S. patent application Ser. No. 13/195,176 filed Aug. 1, 2011 entitled “ARCHITECTURALLY AND THERMALLY IMPROVED FREEZE RESISTANT WINDOW PERIMETER RADIATOR” which was a CIP of the parent U.S. patent application Ser. No. 11/595,382 entitled “ARCHITECTURALLY AND THERMALLY IMPROVED PERIMETER RADIATOR” filed Nov. 8, 2006.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2060936 | Haag, Jr. | Nov 1936 | A |
| 4548570 | Hahn | Oct 1985 | A |
| 6533030 | Mitrovic | Mar 2003 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20150144310 A1 | May 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13195176 | Aug 2011 | US |
| Child | 14614142 | US |
