SYSTEMS, METHODS AND DEVICES FOR BUILDING ENVELOPE SYSTEM
A building envelope system includes several elements that aid in reducing heat transfer. Panels combining insulation and radiant barrier materials, a weather-resistant textile (e.g., canvas) cover, tube insulation, a vestibule and strip curtains can all contribute to reducing heat transfer and, correspondingly, reducing energy requirements for heating and/or cooling. The panel can include a tongue and groove or similar (e.g., dovetail) coupling allowing two panels to mate. The panel can include a top insulation layer, top air gap layer(s), radiant barrier layer(s), bottom air gap layer(s), phase change insulation layer(s) and a bottom insulation layer. By including an air gap on both sides of the radiant barrier, the radiant barrier is effective at reducing heat transfer in and out of the shelter.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 62/207,299 filed Aug. 19, 2015, which is incorporated by reference herein in its entirety.
TECHNICAL FIELDThe present disclosure relates to building insulation and more specifically to insulation of temporary building insulation.
A detailed description of systems and methods consistent with embodiments of the present disclosure is provided below. While several embodiments are described, it should be understood that the disclosure is not limited to any one embodiment, but instead encompasses numerous alternatives, modifications, and equivalents. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments can be practiced without some or all of these details. Moreover, for the purpose of clarity, certain technical material that is known in the related art has not been described in detail in order to avoid unnecessarily obscuring the disclosure.
It can be difficult to install building envelope technologies on structures inherently designed with limited interior space. Insulation and radiant barrier materials are designed with the implicit assumption that they are being put into a permanent structure and that it does not matter how much space they take up. However, a temporary building, such as a construction trailer or an ISO shelter (a military portable building), does not fit those assumptions. In addition, some homes and offices that are being developed are based on structures made from used shipping containers.
Temporary buildings can have strict limitations on their exterior dimensions. These shelters are often shipped over the road and have to fit within standard lanes. In other embodiments, the shelters are the same size as, or packed into, shipping containers for ocean shipment. Thus, there is a limit on their exterior dimension which inherently limits their interior space to start with. In some solutions, the insulation, rather than the inside space, is compromised. For instance, if six inches of insulation were put on each of the wall and ceilings inside a military ISO shelter, a sixth of the interior space would be lost. Currently, a military ISO shelter has an insulation value of about R4.
In some situations, temporary buildings do not have access to conventional electric infrastructure, but instead use standalone generators, usually based on liquid fuels like diesel or gasoline. In order to use a fueled generator, fuel is shipped in. These small generators operate at about 35-40% fuel efficiency, relative to the 50-55% efficiency of utility-scale generators. In addition, shipping fuel in very small batches to remote locations can cost a substantial amount of money. In some stationary and secure, but remote, locations such as rural Alaska, delivered fuel may cost $6-12 a gallon. Military shipment of fuel into areas where combat operations are ongoing has been estimated to be as high as $400-1,000 a gallon. It is therefore desirable to reduce the fuel required to provide power to the temporary buildings frequently used in remote locations. Reducing the amount of energy used to change the temperature inside the buildings can be significantly helpful with regard to reducing fuel consumption, as maintaining a comfortable interior temperature can be the largest single use of energy, sometimes accounting for 50-70% of the energy used in these buildings.
A mechanism through which people can get the benefit of building envelope technologies is achieved by assembling a building envelope structure outside a temporary building. This outside structure allows for improving the insulation (R) value and also provides a mechanism to provide the benefit from other building envelope heat management technologies that do not have an insulation R value per se, such as radiant barrier. The building envelope panels are lightweight and can be assembled and disassembled and reused several times. The panels act as a building envelope, by providing one or more building envelope systems in a single form that can be used without affecting interior space constraints. In the embodiment described, a panel is constructed of foam insulation, enclosed air pockets, and a radiant barrier, as illustrated in
The portable externally assembled building envelope panels incorporate insulation and radiant barrier to prevent or reduce heat transfer in both directions. In some embodiments, the mounting of the radiant barrier allows for at least three quarters of an inch of airspace on each side, allowing the barrier to work in the same manner in both directions. Where a radiant barrier is mounted directly on one of the pieces of insulation with an air gap only on one side, the barrier blocks or reduces heat transfer in one direction, but it will not block heat transfer in both directions. To block or reduce heat transfer in both directions, airspace or something similar (e.g., vacuum, aerogel) is needed on both sides. A panel with airspace or something similar on both sides can thus block or reduce heat transfer in both directions, allowing the radiant barrier foil to be effective in both winter and summer.
By being able to assemble the building envelope outside the shelter, using panels, the building envelope can be extended to the ground. In some embodiments, these temporary buildings are mounted on railroad ties above ground. A placement crew will position railroad ties, or something similar, and put the temporary building on top of the ties as a foundation. However, this placement allows air to blow underneath the floor. Wind can remove heat that has been conducted to the bottom of the building in winter or provide a continuous supply of new heat to a floor during summer. In some embodiments, the building envelope system can be placed around a building, without attaching it to the building.
In some embodiments, a compressible insulating material, such as an insulating fiberglass, is formed into tubes or placed into plastic tubes. The tubes are placed and/or compressed underneath the building so as to block or reduce the airflow. The panels can be built so as to reach to the ground, further restricting air flow and providing additional insulation around the tubes. The tubes allow a dead air space to be created under the building to prevent or reduce air flow underneath the temporary building. Having the dead air space underneath the temporary building adds some insulation value, as opposed to having a live air space underneath the temporary building from which air movement can remove or add heat through the floor.
In one embodiment, heat transfer is slowed by providing insulation directly by the presence of the foam insulation material, and additionally by the mounting of a radiant barrier inside the foam insulation with air on both sides of the radiant barrier inside the foam insulation, and further by using additional compressible insulation and/or the ability of the panels themselves to cover the air gap between the building and ground and thus to prevent or reduce air from flowing freely underneath the building.
Weather resistance can be achieved by covering the building envelope assembly with a canvas or other weather-resistant tarpaulin that is fitted to a size of the assembled building envelope. The tarpaulin prevents or reduces the foam insulation from being exposed directly to the atmosphere. By using the foam insulation in addition to putting such a cover over it, the building envelope system has been able to survive hostile weather conditions, such as high winds, snow, sleet and rain.
Additional building envelope subsystems can reduce further heat transfer. For example, a strip curtain inside the door and/or a portable vestibule can be used to reduce heat loss through mass transfer (i.e., these systems will prevent or reduce conditioned air from leaving the temporary building and being replaced with unconditioned air from the local environment). In an embodiment, the portable vestibule can be an aluminum frame around the door of the temporary building with a textile over the frame. A vestibule allows enough time for an inside door to close before a person gets to the outside door of the vestibule or allows enough time for an outside door of the vestibule to close before the person gets to the inside door of the temporary building. Either a vestibule or a curtain immediately inside the door allows for the trapping of the conditioned air inside the temporary building as much as possible. However, to the extent that the conditioned air is lost, if a vestibule is present, the air is lost to the weatherized enclosure rather than just directly to the atmosphere. If wind is blowing towards the door, use of a second door slows down the heat loss due to trapping the conditioned air in the vestibule instead of allowing the conditioned air to be swept away by the wind. In some embodiments, the vestibule covering itself can be insulated to have a radiant barrier inside.
Such techniques aid in reducing loss of conditioned air caused by opening or closing the door to the temporary building. In some embodiments, the temporary building is small (e.g., military ISO shelters and shipping container-based buildings are often as small as 8′×8′×20′, and office trailers are commonly about 8′×8′×40′). The door is large relative to the size of the structure and the air contained within. When the door is opened, the conditioned air (e.g., cold air or hot air, depending on season) escapes out the door. The heater or cooling unit is then tasked to make up for the air that was lost. These techniques allow a slowing of the air loss by having a strip curtain and/or vestibule that reduces the amount of heat or cold waft that occurs.
By using the panel technology, heat transfer from the building to the exterior environment, and heat transfer from the exterior environment to the building can be reduced. For example, a bare ISO shelter in the field by itself, without a building envelope system, would have its top metal surface exposed to the sun. Absorption of solar radiation is going to cause the temperature of that metal surface to go up well above the ambient air temperature. On a 90° F. day, the top surface of a bare shelter might be 110° F. or 120° F. The air conditioner inside the shelter is thus working against a temperature of 120° F. By putting the panels up outside the structure, a situation is created in which the effect of the absorption of heat on the top surface of the building during the summer is minimized. Instead of the highest temperature in direct sunlight occurring on the top surface of the building, it now occurs at the top of the insulation. The high temperature at the surface is now a lower temperature than it would otherwise have been, because the insulation product does not heat up as readily as the metal roof. Furthermore, this lower high temperature, at the top of the building envelope, now encounters thermal resistance that slows the transfer of that heat to the interior of the building. The air conditioner will work against a lower temperature and will not have to run as long.
A canvas covering can be placed around the insulation system, which does not transfer heat as easily as the metal surface of a bare shelter. In addition, to the extent there is radiant heat transfer, total heat transfer is reduced by the radiant barrier inside. For example, with the building envelope panels, the top surface is now canvas and will not absorb heat as readily. To an extent that it does absorb heat, the heat will be transferred to the shelter interior through the multiple layers of thermal barriers that resist the heat transfer. The air conditioner will work against a lower temperature and will not have to run as long.
In some embodiments, panels can be constructed with one, two, three or four inches (or other amounts) worth of foam insulation; two inches worth of air gap (or other amounts); and one or more pieces of radiant barrier foil in the center of the air gap for most of the structure (other numbers of radiant barrier layers are also possible). Insulation can be used for structural integrity to be able to mount the radiant barrier. In some embodiments, a panel is actually two subpanels mirror imaged with foil in between.
A cross section of an installed building envelope system can include a canvas cover, an outside insulation panel, an air gap with supporting structure, a radiant barrier, an air gap with supporting structure and an inside insulation panel.
A wrap (e.g., a canvas wrap) can be placed over the entire structure. The canvas can provide weather resistance, structural integrity and an ability to select a color. The color can contribute to the net thermal resistance. A black canvas cover can absorb heat during the winter; a white canvas cover can reflect heat in summer. Different colors, or, e.g., camouflage patterns can also be used for concealment in addition to energy conservation.
In some embodiments, foam insulation can be used for insulation panels due to a good combination of being light and durable. In some embodiments, the insulation is a type that is actually used in conjunction with typical permanent buildings. A durable insulation allows for the panels to resist the set up and striking cycles for temporary buildings. Other foam-based insulation can also be used, such as other polymer-based insulation. Mineral-based insulation (mineral wool, glass fiber, aerogel, etc.) can also be used within the blocks if desirable, e.g., for reasons of cost or additional fire resistance.
Foam insulation can be used to provide structure to support the first air gap. In one embodiment, foam insulation is placed around the edges of a panel to form a tongue and groove connector, and to facilitate assembly of the panels, while simultaneously surrounding and providing the structure, the air gap and the mounting surface for the radiant barrier. In addition, a center strip can also provide structural support for the radiant barrier.
A radiant barrier, consisting of a thin layer of reflective material, can rest on the strips of foam insulation supporting the air gap. In some embodiments a structurally reinforced metal foil (e.g., aluminum) is used. In other embodiments, a radiant barrier is formed with a sheet of metallized polymer. (e.g., aluminized Mylar) A mirror image of the air gap and foam panel can then be placed on the other side.
In some embodiments, more than two air gaps and/or more than one radiant barrier are used. For example, two sets of internal supports and two pieces of metal foil can be used. In some embodiments three or more radiant barriers are used.
Phase change insulation can also be used, as an additional layer that rests on the interior insulation layer, facing the air gap and the radiant barrier, to provide heat transfer resistance via the thermal capacitance effect for which phase change insulation is designed. For example, from the point of view of a roof panel, a phase change insulation sheet based on a wax that melts at about 85° F. can be embedded inside the roof panel. This additional layer of material can further slow heat transfer, because the wax will have to melt completely or significantly before the heat can go past the phase change insulation. For instance, in a desert climate with hot days and cool nights, on a hot summer day of 100° F. outside, excess heat that has worked its way through the top layer of insulation, air gap, radiant barrier and second air gap would then reach the phase change material and stall until sufficient heat has been captured to melt the wax. Until that time at which the wax is melted, the maximum temperature that the air conditioner inside the building would “see” would be 85° F., because the heat energy melts the wax before it is transferred through the next layer of insulation and into the shelter. The temperature at the phase change layer stays at the melting temperature of the wax until the wax has sufficiently melted. By absorbing the heat to make a phase change of the wax, time at a lower temperature is gained.
In some embodiments and by the time the heat has melted the wax, it is possible that sufficient time will have passed that the outside temperature during evening hours is now below 85° F. The wax will start to solidify again because the temperature has dropped below 85° F., the melting point of the wax. As the wax solidifies it releases heat, some of which will escape back up through the top part of the panel, but some of which will escape into the shelter through the bottom part, actually helping to heat the shelter at night. The energy captured by the wax during the day and prevented from getting into the shelter can thus be used by the building to help heat it at night (or vice versa during the opposite season). Depending on the embodiment, a layer of phase change insulation can be placed on the bottom side or the top side of a layer of foam before the air gap.
In some embodiments, assembled panels can be held together by a tongue and groove construction of the panels themselves. The entire structure, once it gets assembled around the shelter, can be held together by lag bolts and/or the covering (e.g., canvas cover). The lag bolts can add additional structural integrity. Although tongue and groove construction is mentioned as a method of inter-panel coupling, other inter-panel couplings are possible. For example, dovetail joints or butt joints are also possible.
In one embodiment, a retrofittable outdoor building envelope system includes several elements. The panels (including insulation, air gaps, radiant barrier and phase change insulation), canvas cover, and tube insulation can all contribute to reducing heat transfer and, correspondingly, reducing energy requirements for heating and/or cooling.
Additional heat transfer prevention or reduction can occur at the door. As the building is small, when the door is opened much of the conditioned air is lost to the environment. Two systems can be used to slow the loss. These include installing a strip curtain at the door and assembling a portable vestibule around the outside of the door. When a person is going in or out, it allows enough time for the door to close before arriving at a second door. This allows trapping of the conditioned air inside the shelter. However, to the extent that the air escapes the shelter, the air escapes to the weatherized enclosure rather than directly to the atmosphere. The vestibule covering can be insulated and/or have a radiant barrier inside.
Reference throughout this specification to “an example” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the present invention. Thus, appearances of the phrase “for example” in various places throughout this specification are not necessarily all referring to the same embodiment.
As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on its presentation in a common group without indications to the contrary. In addition, various embodiments and examples of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of materials, frequencies, sizes, lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
Those having skill in the art will appreciate that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims.
Claims
1. A building envelope system comprising:
- a set of panels configured to surround a temporary building, the panels comprising: a set of layers, the layers comprising: a top insulation panel; a bottom insulation panel; a radiant barrier configured to reduce heat transfer through radiation; a top supporting structure substantially a same size as the top insulation panel and coupled to the top insulation panel and the radiant barrier, the top supporting structure configured to provide a first air gap in conjunction with the radiant barrier and the top insulation panel, the top supporting structure comprising a supporting member having a thickness that causes a separation between the top insulation panel and the radiant barrier resulting in the first air gap; and a bottom supporting structure substantially the same size as the top insulation panel and coupled to the bottom insulation panel and the radiant barrier, the bottom supporting structure configured to provide a second air gap in conjunction with the radiant barrier and the bottom insulation panel layer; and an inter-panel coupling at an edge of the panel configured to couple with another panel;
- a compressible layer of insulation configured to be installed below the panels and in a gap between the temporary building and a ground surface; and
- a cover configured to surround the set of panels and shaped to conform to a shape of the building with the panels installed.
2. The building envelope system of claim 1, wherein the inter-panel coupling is a tongue and groove coupling or dovetail coupling.
3. The building envelope system of claim 1, wherein the set of panels further comprises removable panels to cover windows and doors of the temporary building.
4. The building envelope system of claim 1, wherein the set of panels are configured to be placed around the temporary building without attaching to the temporary building.
5. The building envelope system of claim 1, wherein the compressible layer of insulation is formed into a tube shape.
6. The building envelope system of claim 1, further comprising a vestibule configured to attach to a subset of the panels and surround a door of the temporary building.
7. The building envelope system of claim 1, further comprising a set of strip curtains configured to attach to a doorframe of the temporary building and reduce airflow between an inside of the temporary building and an outside of the temporary building.
8. The building envelope system of claim 1, wherein the first air gap is enclosed.
9. (canceled)
10. The building envelope system of claim 1, further comprising a layer of phase change insulation attached to the top insulation panel or bottom insulation panel.
11. The building envelope system of claim 1, wherein the cover is formed from a weather-resistant textile material.
12. The building envelope system of claim 11, wherein the weather-resistant textile material is a canvas material.
13. A panel of a building envelope system comprising:
- a top insulation panel;
- a bottom insulation panel;
- a top supporting structure attached to the top insulation panel and configured to form a first air gap with the top insulation panel;
- a bottom supporting structure attached to the bottom insulation panel and configured to form a second air gap with the bottom insulation panel;
- a radiant barrier attached to the top supporting structure and configured to form the first air gap between the radiant barrier and the top insulation panel using the top supporting structure and form the second air gap between the radiant barrier and the bottom supporting structure and the bottom insulation panel using the bottom supporting structure; and
- an inter-panel coupling at an edge of the panel configured to couple with another panel.
14. The panel of claim 13, wherein the inter-panel coupling is a tongue and groove coupling or a dovetail coupling.
15. The panel of claim 13, wherein the bottom supporting structure further comprises a perimeter supporting member and middle strip supporting member having a thickness that causes a separation between the radiant barrier and the bottom insulation layer creating the second air gap.
16. The panel of claim 15, wherein the supporting member is constructed of a same material as the top insulation layer.
17. The panel of claim 13, further comprising a layer of phase change insulation attached to the top insulation layer.
18. The panel of claim 13, further comprising a layer of phase change insulation attached to the bottom insulation layer.
19. A method of installing a building envelope system on a temporary building, the method comprising:
- storing a set of panels for the building envelope system within the temporary building during transit, the panels comprising: a top insulation layer; a bottom insulation layer; a top supporting structure attached to the top insulation layer and configured to provide a first air gap with the top insulation layer; a bottom supporting structure attached to the bottom insulation layer and configured to provide a second air gap with the bottom insulation layer; a radiant barrier attached to the top supporting structure and configured to form the first air gap between the radiant barrier and the top insulation layer using the top supporting structure and form the second air gap between the radiant barrier and the bottom insulation layer using the bottom supporting structure; and an inter-panel coupling at an edge of the panel configured to couple with another panel;
- coupling, using the inter-panel coupling of the set of panels, the set of panels together along an outside surface of the temporary building to form an installed set of panels; and
- covering the installed set of panels with a pre-formed cover to conform to the dimensions of the installed set of panels.
20. The method of claim 19, wherein coupling, using the inter-panel coupling of the set of panels, the set of panels together along the outside surface of the temporary building further comprises installing the set of panels without permanently attaching the panels to the outside of the building.
21. The method of claim 19, further comprising placing a compressible layer of insulation below the panels and in a gap between the building and a ground surface.
22. The method of claim 19, further comprising attaching a vestibule around a door of the temporary building.
23. The method of claim 19, further comprising attaching a set of strip curtains to cover an entry into the temporary building.
24. The building envelope system of claim 1, wherein the set of layers further comprises an additional radiant barrier and additional supporting structure between the bottom supporting structure and the bottom insulation panel to form a structure.
Type: Application
Filed: Oct 29, 2015
Publication Date: Feb 23, 2017
Applicant: MARK G. MILLER, INC. (Layton, UT)
Inventors: Gregory Whiting (Salt Lake City, UT), Nathan Nelson (North Ogden, UT)
Application Number: 14/927,050