US20140259977A1

US20140259977A1 - Sustainable Building System

Info

Publication number: US20140259977A1
Application number: US14/217,263
Authority: US
Inventors: Timothy McDonald; Howard Steinberg; Patrick McDonald; John McDonald; Robert Benson
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-03-15
Filing date: 2014-03-17
Publication date: 2014-09-18

Abstract

The disclosure relates to a sustainable building system (SBS) that is affordable, capable of being replicated at a small and large scale, significantly reduces both the heating and cooling loads of the building as well as the total energy that the building consumes. Energy consumption can be reduced sufficiently that the building is capable of net-zero-energy status. That is, a building made using the system, method and components described herein can, with the inclusion of appropriate renewable energy technologies, generate on site all the energy that the building needs. Specific to this SBS is the design of a super-insulated and nearly air-tight building thermal envelop, that is, to the greatest extent possible, thermal-bridge-free and that has incorporated into that envelope high performance windows and doors.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is entitled to priority to U.S. provisional patent application 61793,797, filed 15 Mar. 2013, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Others have described a Passive House Standard, which is a building standard developed by the International Passive liotise in Darmstadt, Germany, founded by Dr. Wolfgang Fiest, and Passive House Institute US, developed by founder Katrin Klingenberg, Ohio. That standard has three requirements: (i) a maximum projected Heating and Cooling load of 4.75 thousand British Thermal Units per square foot per year (kBTU/sf/year); (ii) a maximum Total Energy demand of 38 kBTU/sf/year; and a maximum measured air-tightness of 0.6 air changes per hour (ACH) at 50 Pascals of pressure.
The context for the subject matter described herein involves what the Passive House Standard refers to as a “Fabric First” approach to building science and the design of high-performance and net-zero-energy buildings. This means that if one focuses on the “fabric” of the building first, i.e., the thermal envelop, rather than the technological machines within that thermal envelope that produce heating, cooling, lighting, hot water and ventilation more or less efficiently, and if one focuses on designing that thermal_—envelop as a super-insulated and air-tight “fabric” or “coat” for the building, then one can reduce the heating and cooling requirements or loads by up to 90% of what a typical “code compliant” building requires. Second, if one designs that “fabric” as a super-insulated and air-tight thermal envelop, the heating, ventilation and air conditioning systems get significantly smaller (as their ‘loads’ can be roughly one ninth of a typical code compliant building), more efficient and therefore significantly higher performing. Similarly domestic hot water, lighting, and appliance systems can also designed as extremely efficient and integral instruments of a building system. If one reduces a building's energy requirement by up to 90%, then the remaining 10% of energy needed for that building can be readily met with a relatively small amount of on-site renewable energy generation in several forms (photovoltaic power, solar thermal heat, geothermal hydronic heating and cooling, or the like), allowing buildings to achieve net-zero-energy or net-positive-energy status.
The subject matter disclosed herein provides buildings, building components, and methods of making buildings that yield structures having significantly reduced energy requirements.

BRIEF SUMMARY OF THE DISCLOSURE

This disclosure relates to a system for modular assembly of a building. The system includes a plurality of building modules including a plurality of outer building modules (i.e., modules which include a surface which ultimately becomes a portion of the exterior surface of the assembled building). The system also includes an envelope patch for sealing gaps between the modules to exclude airflow from passing between the modules. Each of the outer building modules has an envelope material on the portion of the building's exterior face that occurs on the module. After the modules are assembled to form the building, gaps between the envelope materials on the various modules are sealed using the envelope patch, thereby creating a substantially non-perforated envelope that blankets the building exclusive of doors, windows, and utility openings. In those openings, precautions are taken (e.g., high efficiency doors and windows and careful insulation of unused portions of utility openings) to minimize energy loss. These characteristics, together with selection of appropriate insulating materials in the structural elements of the modules, result in an energy-efficient building that can satisfy the Passive House standards and that can, with the installation of energy-generating elements such as solar panels, result in a net-zero- or net-positive-energy building.
An important component of the building and modules described herein is an energy-conserving air exchanger and ventilator combination that can be assembled with the building modules to form the building. This system transfers heat energy between interior air being exhausted from the building and exterior air being drawn into the building for ventilation. This system can significantly reduce the energy required to heat or cool the interior of the building,
Another important component of the building and modules described herein is an energy monitoring system that can be operably assembled with the building modules to permit monitoring of energy use within the assembled building. The energy monitoring system permits a person (or an automated system directed by a person) to identify sources of energy use within the building and to adjust the building or As characteristics to modulate energy use.
An important characteristic of the building system is its modularity and corresponding transportability. Each building module can be designed to be shippable by any desired means, such as by truck on local roads or interstate highways. Thus, the building modules can be designed to have specified or not-to-exceed dimensions, such as a height not greater than 12 feet, a length not greater than 70 feet, and a width not greater than 16 feet.
The building modules can be manufactured at a location distant from the desired site of building construction, shipped to the site, and there assembled.

DETAILED DESCRIPTION

The disclosure relates to a sustainable building system (SBS) that is affordable, capable of being replicated at a small and large scale, significantly reduces both the heating and cooling loads of the building as well as the total energy that the building consumes. Energy consumption can be reduced sufficiently that the building is capable of net-zero-energy status. That is, a building made using the system, method and components described herein can, with the inclusion of appropriate renewable energy technologies, generate on site all the energy that the building needs. Specific to this SBS is the design of a super-insulated and nearly air-tight building thermal envelop, that is, to the greatest extent possible, thermal-bridge-free and that has incorporated into that envelope high performance windows and doors.
The design of this super insulated and nearly air-tight thermal envelop and building technology system also incorporates low energy heating, cooling and energy recovery ventilation systems, as well as low energy lighting systems, appliances, domestic hot water systems and energy monitoring systems. This building technology is designed such that it can be built in a modular building factory, built via “panelized” pre-fabricated method, as well as site or “stick-built”.
The present invention is related to the design and construction of buildings that are affordable, considered “high-performance” and have the ability to reach Net-Zero-Energy status. What is unique about this invention is that our Sustainable Building System (SBS) is designed to work with conventional building materials, technologies and practices, and designed to be built with a conventional workforce with limited training The significant invention of our SES involves HOW we put these conventional materials together, how the details are designed such that there is limited thermal-bridging between inside and outside within the thermal envelop and limited “punctures” or openings between the inside and the outside of a building.
The sustainable building system (SBS) described herein is made up of the following components. At a macro scale, the building modules are conceptualized as cells of built space rather than individual, self-contained objects, allowing the modules, or boxes, to be assembled in infinite configurations to accommodate various architectural designs. This necessitates the need to air seal each module to the next, on site, to maintain a continuous air seal and thermal envelope across all exterior walls of the building enclosure.
Energy Envelope Design
The design of the total assembly of modules, panels, or site built materials which make up the building is initially designed utilizing energy modeling software developed by the Passive House Institute to determine the minimal amount of insulation required, both in the walls and on the exterior, based on the building's geographical location, specific orientation to the sun to eliminate thermal transfer through the building envelope necessary to achieve the Passive House certification metrics noted above. The energy envelope in conjunction with the building's mechanical system design, energy efficient appliance and lighting forms the holistic details of the Sustainable Building System.
The Individual Module Envelope
At a micro level, the individual module has been detailed to utilize standard 2×4/2×6 wood frame construction (or other equivalent construction, such as metal stud frame construction) to allow a reasonably skilled carpenter or other builder to build the framework for the building envelope described herein. The walls, ground floor and roof structures are filled with and insulating material such as dense packed cellulose insulation, or a “spray and batt” insulation system which utilizes a layer of closed cell spray foam insulation on the interior of the wall against the backside of the sheathing, with the balance of the framed cavity filled with, for example, standard fiberglass batt insulation.
Exterior Sheathing with an integral water resistant barrier is utilized, which serves as both the moisture barrier as well as the air barrier to the This membrane is placed on the exterior of the framed walls and below the lowest floor module to maintain a continuous air barrier. All joints, junctures in the walls of the modules and limited penetrations in the exterior walls are air-sealed with a bituminous tape or another airflow-occluding material. Similarly, the roof sheathing joints are fully taped. Incorporation of airtight, triple glazed windows and doors are placed so that the exterior surface of these units are placed flush with the sheathing allowing easy air tape sealing of the windows, doors, door thresholds to the sheathing air barrier. All gaps between the windows and door units and the rough framed opening are filled completely with spray foam insulation (or other insulation) and a compressible seal (or other gap-occluding apparatus s used under the door threshold. The interior walls are finished in typical gypsum board construction (or other interior finishing material), and a supplemental chase wall or “utility base board” chase can be added to allow for the running of pipes and wires, and the placement of junction boxes without penetrating the exterior thermal wall enveloped.
The exterior of the sheathing is covered in rigid expanded styrene insulation (XPS) following the taping of all seams. This insulation is run continuously up the walls and under the roof system prior to the parapet walls being anchored through the insulation in order to maintain the thermal bridge free construction. Similarly, the underside of the lowest modules are skinned in air seal taped, air-tight sheathing and XPS insulation, whether the design calls for a basement, crawl space or on grade application to prevent thermal and air penetration from below. ALL joints in the XPS is then tape and sealed with a foil faced tape to provide an additional layer of air sealing to the envelope. All joints of XPS and sheathing are installed on a “staggered” pattern. All utility penetrations and ductwork from below are fully air seated at the penetration point of the thermal envelope, and all ductwork outside the envelope is insulated and treated as an exterior wall thermal envelope to prevent condensation and thermal transfer into the structure. The rigid exterior insulation thickness is detailed in order to insure that the dew point of the wall falls outside the exterior sheathing to avoid moisture within the framed
Rain Screen Construction
Outboard of the XPS insulation, the walls are furred out with ¾″ material (preferably, other thicknesses can be used, of course), anchored to the individual wall frame studs, to create a ventilated cavity which allows any moisture which enters through the building skin to have a path back out. This keeps the majority of all water away from the moisture resistant sheathing.
Green Roof System Option
The top floor module is structurally engineered to support the saturated weight of an extensive or intensive green roof system. The green roof can be physically assembled, including vegetation, in the modular factory so that the system is complete when the top module is placed on site, or done on site. Modular Factory installation takes advantage of the fact that a crane is already on site hoisting the modules, and therefore eliminates the added crane cost and staging requirements to field build the green roof after the building has been assembled; thus further reducing overall building costs. This option is critical to allow for additional green space for the structure, but also to provide a system that meets stormwater management regulations in various municipalities.
The air tight, well-insulated, thermal bridge free construction reduces the energy consumption of the building by up to 90% because thermal transfer is effectively eliminated keeping the heat in in the winter and the cooling in in the summer months, paired with energy efficient mechanical systems, lighting and appliances. As a result, the building's primary energy source is completely electric, eliminating natural gas from the building. This dramatically reduces construction costs by eliminating the introduction of another utility into the building and all associated ventilation requirements for combustible gas systems, and the needed penetrations in the exterior envelope for these exhaust components “although natural gas applications are also acceptable.
Mechanical Systems
A unique portion of our sustainable building system is the design of the heating, ventilation and air conditioning system (HVAC). Given the requirements of our SBS air-tightness levels, mechanical fresh air ventilation is required for any SBS structure. That mechanical ventilation must bring in fresh air to the building, exhaust stale air from the building and minimize energy tosses in the process. This is achieved by using either an Energy Recovery Ventilator (ERV) or a Heat Recovery Ventilator (HRV) and must have efficiencies of at least 75%. These devices include a heat-energy-exchanger and a ventilator to conserve interior heating or cooling by exchanging energy between interior air being exhausted and exterior air being drawn in.
Given the very low heating and cooling demands of these buildings built with our SBS, a single device that delivers a very low amount of heating and cooling combined with an
ERV or HRV is not commercially available in the United States. We have achieved a HVAC system designed for our SBS that meets this need by combining an off-the-shelf General Electric Zoneline brand (or equivalent) PTAC (Packaged Terminal Air Conditioner) air-sourced heat pump, with an off-the-shelf Ultimate Aire brand ERV (or an equivalent) to create an efficient HVAC system that meets the needs of the tow energy heating and cooling demands of our SBS and the ventilation requirements.
The PTAC unit is designed to be a “through-wall” heat pump (typically used in hotels, student dorms, office buildings) whereby one of the coils of the heat pump is directly exposed to the exterior and the other coil of the heat pump is exposed to the interior of the building (i.e., it is within the thermal envelope). Our design for this PTAC involves moving the entire packaged heat pump unit within the thermal envelope, carefully and significantly insulating the duct work on both the fresh air intake and exhaust side of the heat pump within the thermal envelop, thereby being able to significantly reduce the heat losses inherent to the typical “through-wall” design of the heat pump. This is an important improvement in the design and performance of this off-the-shelf heat pump. A second improvement occurs when the duct work of the ERV is connected to the ductwork of the heat pump.
The exhaust side of the ERV connects directly to the fresh air intake side of the outside coil of the heat pump, but only after a damper. Exhaust from the ERV passes over the outside coil of the heat pump before it is exhausted to the exterior. In so doing, the exhaust elevates the temperature of the incoming air, in the winter, lowers it in the summer, and in the process increases the coefficient of performance (COP) of the heat pump, as the COP is entirely dependent on the ambient temperature of the exterior going across the outside coil This “marrying” of the ERV and the PTAC heat pump increases the performance of the heat pump, helping it run at a higher COP regardless of the exterior temperature. This would not be possible for the PTAC heat pump in its originally designed state.
Another important feature of this HVAC design for our SBS system involves a bypass damper, mechanically controlled and linked to temperature sensors inside and outside the thermal envelop. For instance, if the interior temperature is significantly higher than the exterior temperature, the ERV will turn off, as well as the compressors on the heat pump, and the damper will open, fans in the ERV will turn on and fresh air will be brought in directly to the supply side of the duct work inside the thermal envelope, lowering the temperature of the interior solely without the need for mechanical cooling.
In general, the design of our HVAC system within our SBS is unique, specific to the very particular heating, cooling and ventilation requirements of a nearly air-tight envelope of a
Passive House structure and uses off-the-shelf components in a manner which has not been done before.
Energy Monitoring
The buildings made as described herein can be equipped with energy monitoring devices tied to each of the electrical circuit breakers, and any renewable energy source, to track and collect data on the consumption and production side of the systems. Additionally, room sensors are placed through the building to measure, temperature, air quality (CO2 levels), and humidity to inform the mechanical systems and measure these critical values. Remote and on-site monitoring provides the occupant real time data to alter their usage of the building to increase their energy performance, while also enabling the engineers, legislators and maintenance personnel critical data about the performance of the SBS. Those access to the system, can also alter temperature settings remotely.
Placement of the Modules—Maintaining Air Tight Construction Between Components:
Air Sealing
Each module is placed on top of the next in vertical stacks. The first stack, which is accessible from both sides is mechanically secured to one another utilizing mechanical strap fasteners which are in turn air sealed with bituminous tape, and the horizontal joints between each module are also air sealed with bituminous tape. In placing the second adjacent module stack, the first base module is placed and the top plate of the newly placed box is tape sealed to the adjacent (first stack) box as an inside corner detail in order to seal the two boxes together horizontally. Prior to setting the subsequent module in the second stack, two side by side layers of expanding foam tape or gasketing material (or any equivalent expanding or expandable material) is placed on the same top plate to form a horizontal airtight seal between the two vertically placed boxes. Thus, inter-module gaps are both filled with the expanding material and sealed with a metal-faced or bituminous tape, reducing or eliminating air infiltration from the exterior of the resulting building and the spaces between the modules. The other three sides of the newly placed module stack remain exposed and accessible to install the standard horizontal bituminous taped seam.
The above stated sequence is repeated for each new vertical and horizontal placement of modules as the building expands.
Hoisting
In order to avoid penetrations in the exterior envelope of the modules, a key restriction in air-tight construction, a modified hoisting method has been designed. Centered on the thickness of the exterior walls of each module, within the floor framing cavity, a steel bracket with a connector nut is lag bolted into the floor structure at the quarter points of the module's long walls. A continuous piece of Electrical Metal Tubing (EMT) is placed vertically in the exterior module walls in tine with the connector nut and run up through the top plates of the box construction. Removable threaded steel rods with eye bolts on the end to connect to the Crane spreader bar. The EMT is placed to maintain alignment to the base nut and a conduit for the steel rods to penetrate the wall insulation. After hoisting the modules, the rods are removed and re-used on the next lift. The remaining hole is filled with spray foam insulation and taped with air seal tape. This solution modifies the more typical approach in which holes are placed in the lower side wall of the module, within the floor framing, and a removable steel hoist cable is run through the box. After the module is in placed with the traditional method, there is no way to seal these holes after the fact.
It is a goal of the subject matter described herein to provide to builders, developers, politicians, institutions, building manufacturers, modular building manufacturers, panelized building component manufacturers, homeowners and the general public an affordable and high-performance, net-zero-energy-capable and sustainable building system that would significantly increase the design and energy codes and standards by which new buildings are to be conceived and built; significantly reducing the energy that buildings consume and significantly reducing the carbon dioxide emissions that come from the making and operating of buildings.
The disclosure of every patent, patent application, and publication cited herein is hereby incorporated herein by reference in its entirety.
While this subject matter has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from the true spirit and scope of the subject matter described herein. The appended claims include all such embodiments and equivalent variations.

Claims

What is claimed is:

1. A system for modular assembly of a building, the system comprising a plurality of building modules including a plurality of outer building modules and an envelope patch,

each of the outer building modules including at least one exterior face having a portion of an envelope as a component of the exterior face,

the building modules being assemblable to form a building having the envelope on the exterior faces thereof, and

including sufficient envelope patch to bridge the inter-module gaps in the envelope.

2. The system of claim 1, further including an energy-conserving air exchanger and ventilator that can be assembled with the building modules to form the building.

3. The system of claim 1, further comprising an energy monitoring system that can be operably assembled with the building modules to permit monitoring of energy use within the assembled building.

4. The system of claim 1, wherein each building module has shipping dimensions wherein its height is not greater than 12 feet, its length is not greater than 70 feet, and its width is not greater than 16 feet.

5. The system of claim 4, wherein the shipping dimensions does not include the vehicle used for shipping the module.

6. A method of assembling an energy-efficient modular building, the method comprising

assembling a plurality of building modules including a plurality of outer building modules

the building modules, when assembled forming a structure having the envelope on the exterior faces thereof and having inter-module gaps in the envelope,

patching the inter-module gaps with an envelope patch, and

sealing all remaining perforations in the envelope with an energy-conserving air exchanger and ventilator to yield the energy-efficient modular building.

7. The method of claim 6, wherein at least some heat-conserving apparatus are selected from the group consisting of a window, a door, and an energy-conserving air exchanger and ventilator.

8. The method of claim 7, wherein at least one heat-conserving apparatus is an energy conserving air exchanger and ventilator.

9. The method of claim 6, further comprising installing within the building an energy monitoring system for monitoring of energy use within the assembled building.

10. The method of claim 6, wherein at least some of the building modules are assembled at a site more than 100 yards distant from the site of the building.

11. The method of claim 10, wherein each distantly-assembled building module has shipping dimensions wherein its height is not greater than 12 feet, its length is not greater than 70 feet, and its width is not greater than 16 feet.

12. A building made by the method of claim 6.