Patent Application
20120318475
None.
1. Field of the Invention
This invention relates to building energy systems for both new and retrofit construction.
2. Background
Traditionally, houses were commonly constructed from solid masonry walls with no insulation in the walls. Windows were typically single glazed and the houses were heated by open fireplaces in each room. Because the buildings were not air tight, there was no need for a separate ventilation system. In upgrading these older buildings to higher levels of wall insulation and air tightness, the challenge is to improve the building's energy efficiency without destroying its architectural integrity.
One approach is to add vacuum insulation panels (VIPs) to the interior face of the masonry walls. However, because VIPs are vapor barriers, there is no inward drying. For some installations, interior retrofits can be risky and result in condensation, mold, timber rot and freeze/thaw damage. As proposed by Glover and Rosen in a recent IVIS conference paper, one strategy is to incorporate a narrow, ventilated and depressurized cavity adjacent to the stone wall. However, installing VIP panels may not be straightforward, especially if the interior stone surface is uneven.
Upgrading the insulating performance of traditional single windows is also an aspect of improving the energy efficiency of older buildings. Recently, there has been wide-scale commercialization of low-emissivity coatings. For high performance sputtered low-e coatings, there are two main types: solar control and solar gain. Comparing the two coatings, the emissivity of the solar control coating is lower resulting in reduced heat loss. However, in a comparison study by the National Research Council of Canada using side-by-side test house monitoring, the study showed that during the heating season overall building energy consumption is 10 per cent lower with solar gain low-e coatings because of higher direct solar gains. However, during the cooling season, building energy consumption is higher with solar gain low-e coatings unless devices such as exterior blinds or shutters are used to help block out the solar gains. Typically, these high performance sputtered coatings are located on the cavity glass surfaces of an insulating glass unit; however, more recently, exterior sputtered low-e coatings have been developed that typically increase the center-of-glass insulating performance from R-4 to R-5.
Vacuum glazing is a new energy efficient window product that is poised for commercialization. As there is no heat loss across the small vacuum cavity through convection or conduction, the main source of glazing heat loss is through radiation. By using an ultra low-e coating, radiation heat loss is reduced to a minimum. This provides for R-15 center-of-glass performance for a double-glazed unit, but direct solar heat gains through south-facing windows can be substantially reduced during the heating season.
Generally, with current energy efficient construction techniques there is an airtight, highly insulated building envelope and a centralized heating, ventilating and air conditioning (HVAC) system. A ducting system is used to transport and return ventilation air to the centralized HVAC equipment. With improvements to the air tightness of new building construction, air-to-air heat exchangers were developed with the out-going polluted air preheating the incoming outside air. The installation of an air-to-air heat exchanger requires a house with a centralized ducting system. For older houses, it is difficult to retrofit a centralized ducting system because of the need to hide the large duct work within the existing interior walls.
Displacement or air stratified ventilation is an alternative strategy to centralized ventilation ducting systems and with this strategy, fresh preheated or cooled ventilation air is gradually introduced at a low level at a temperature slightly lower than room temperature. As the room occupants generate air pollutants, the polluted air slowly rises and it is then fully exhausted from the room through high level vents. Unlike conventional ventilation systems, none of the polluted air is returned and re-circulated through the building and this provides for higher indoor air quality. U.S. Pat. No. 4,955,285 discloses the advantages of combining displacement ventilation with high R-value windows. Because of the need for air stratification, there should be no down drafting at the windows and this demands the use of high-R windows.
With new house construction, by installing high levels of insulation combined with an air tight barrier, it is feasible to substantially reduce heating and air conditioning loads particularly if high performance windows are incorporated. However, even with these substantially reduced energy loads, HVAC equipment costs remain comparatively high because of the need for centralized ducting systems and the cost of installing different pieces of high efficiency equipment for a range of different heating and cooling applications. One strategy for reducing the cost and complexity of the heating/cooling devices is to use an integrated mechanical system (See Allen, Drerup, White Ltd., Technical Report, Advanced Passive Solar Design, National Research Council, Ottawa, Canada, 1985).
An integrated mechanical system consists of a cold thermal storage tank, a hot thermal storage tank and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank. The hot thermal storage tank supplies heat for various operations, including: space heating, domestic hot water heating, and ventilation air preheating. The cold thermal storage tank supplies cooling for various operations, including: space cooling, dehumidification, ventilation air cooling in summer, ventilation air heat recovery in winter, grey water heat recovery, and food refrigeration. Despite being promoted in a high profile demonstration project (see: Canada's Energy Miser, Popular Science Magazine, December 1990), this technology has yet to be successfully commercialized. There are various factors involved, including the need to balance daily heating and cooling loads both in the summer and winter.
Particularly in regions where nuclear energy is used to meet base load, it is important that peak loads in summer and winter are similar. Given the present availability and low pricing for natural gas, there is a general trend towards using natural gas for space heating in the winter and electricity for air conditioning in the summer. Such a trend accentuates problems of grid management, including an increase in peak demand during summer. A related issue is that with global warming and extreme hot summer weather, air conditioning may become a necessity rather than a luxury. To encourage consumers to reduce electrical demand at peak periods, utility companies are installing smart meters as well as introducing special off-peak electrical rates. However, for homeowners, it is inconvenient to wait to turn on the dishwasher or the clothes dryer in the middle of the night.
In accordance with an embodiment of the present disclosure, there is provided a building energy system comprising a building enclosure having an interior and exterior, and comprising: an insulated building envelope that incorporates at least one perimeter fenestration assembly; an integrated mechanical system that provides heating and cooling for various functions, and comprises a cold thermal storage tank, a hot thermal storage tank, and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank; and, an air stratified ventilation system comprising at least one upper exhaust outlet and at least one lower supply intake that connect to the exterior of the building enclosure, wherein said upper exhaust outlet incorporates a heat exchanger that recovers heat from outgoing air, and wherein said heat exchanger is connected to the cold thermal storage tank of the integrated mechanical system; wherein energy performance of said at least one fenestration assembly may vary or be automatically controlled such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with a further embodiment of the present disclosure, electrical use and peak load demand are at least partially reduced.
In accordance with a further embodiment of the present disclosure, at least one central space that is connected to said lower supply intake and one or more perimeter rooms located adjacent to said central space, wherein said one or more perimeter rooms comprises: one or more lower wall vents that connect to said central space; and one or more upper vents connected to said upper exhaust outlet.
In accordance with a further embodiment of the present disclosure, said building enclosure comprises two or more levels, and wherein said central space is continuous at least in part between said two or more levels.
In accordance with a further embodiment of the present disclosure, said central space comprises an open staircase.
In accordance with a further embodiment of the present disclosure, said one or more upper vents is connected to said at least one upper exhaust outlet via a duct that is separated off from said central space.
In accordance with a further embodiment of the present disclosure, any of said one or more lower wall vents is a gap between a floor and a door wherein said gap connects said central space with one of said perimeter rooms.
In accordance with a further embodiment of the present disclosure, there is provided at least one exhaust fan in any of said perimeter rooms for at least partially venting to the exterior of the building enclosure.
In accordance with a further embodiment of the present disclosure, said insulated building envelope comprises at least in part one or more vacuum insulation panels.
In accordance with a further embodiment of the present disclosure, said at least one fenestration assembly comprises at least one moveable and motorized, top supported horizontal sliding insulating glass unit that at least partially overlaps a fenestration opening of said at least one fenestration assembly, and that slides into a pocket located adjacent to the fenestration opening, for varying or controlling the energy performance of said at least one fenestration assembly.
In accordance with a further embodiment of the present disclosure, at least one moveable and motorized top supported horizontal sliding insulating glass unit is a vacuum insulating glass unit.
In accordance with a further embodiment of the present disclosure, there is provided a conventional window on the exterior side of the fenestration opening and the moveable insulating glass unit on the interior side of the fenestration opening.
In accordance with a further embodiment of the present disclosure, there are provided two moveable insulating glass units, wherein a double glazed insulating glass unit is located on the exterior side of the fenestration opening, and a double-glazed insulating glass unit is located on the interior side of the fenestration opening.
In accordance with a further embodiment of the present disclosure, there is provided a Venetian blind located between the two insulating glass units.
In accordance with a further embodiment of the present disclosure, said one or more perimeter rooms are heated or cooled by radiant heating or cooling sources.
In accordance with a further embodiment of the present disclosure, said radiant heating or cooling sources comprise in part hydronic panels or radiators.
In accordance with a further embodiment of the present disclosure, there is provided in each perimeter room one or more room controllers that at least partially control the radiant heating and cooling sources, an exhaust fan and said at least one fenestration assembly for maintaining comfort conditions.
In accordance with a further embodiment of the present disclosure, the one or more room controllers are linked to a central controller that controls operation of the integrated mechanical system such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with a further embodiment of the present disclosure, the central controller is linked to an electrical supply grid such that the integrated mechanical system may be operated in a manner that reduces at least one of electrical use or peak load demand.
In accordance with a further embodiment of the present disclosure, the various heating and cooling functions comprise at least one of space heating, space cooling, domestic hot water, ventilation air heat recovery, greywater heat recovery, clothes drying heat recovery, and food refrigeration.
In accordance with a further embodiment of the present disclosure, electrical power generated from solar energy is used to operate the heat pump.
In accordance with a further embodiment of the present disclosure, incoming air at the at least one lower supply intake is preheated or precooled using ground source heating or cooling sources.
In accordance with a further embodiment of the present disclosure, said at least one exhaust fan at least partially vents to the exterior of the building enclosure pollutants generated inside the building enclosure.
In accordance with a further embodiment of the present disclosure, at least a portion of the solar-generated electrical power is thermally stored and later used for one or more heating and cooling functions.
In accordance with a further embodiment of the present disclosure, there is provided an integrated mechanical system for providing heating and cooling functions in a building energy system comprising: a cold thermal storage tank; a hot thermal storage tank; and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank; wherein said building energy system comprises: a building enclosure having an interior and exterior, and comprising: an insulated building envelope that incorporates at least one perimeter fenestration assembly; the integrated mechanical system; an air stratified ventilation system comprising at least one upper exhaust outlet and at least one lower supply intake that connect to the exterior of the building enclosure, wherein said upper exhaust outlet incorporates a heat exchanger that recovers heat from outgoing air, and wherein said heat exchanger is connected to the cold thermal storage tank of the integrated mechanical system; wherein energy performance of said at least one fenestration assembly may vary or be automatically controlled such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with an embodiment of the present disclosure, there is provided a fenestration assembly for use in a building energy system comprising: at least one moveable and motorized, top supported horizontal sliding insulating glass unit that at least partially overlaps a fenestration opening of said fenestration assembly, and that slides into a pocket located adjacent to the fenestration opening, for varying or controlling the energy performance of the fenestration assembly; wherein said building energy system comprises: a building enclosure having an interior and exterior, and comprising: an insulated building envelope that incorporates at least one of said fenestration assembly; an integrated mechanical system that provides heating and cooling for various functions, and comprises: a cold thermal storage tank; a hot thermal storage tank; and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank; an air stratified ventilation system comprising at least one upper exhaust outlet and at least one lower supply intake that connect to the exterior of the building enclosure, wherein said upper exhaust outlet incorporates a heat exchanger that recovers heat from outgoing air, and wherein said heat exchanger is connected to the cold thermal storage tank of the integrated mechanical system; wherein energy performance of said at least one fenestration assembly may vary or be automatically controlled such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with a further embodiment of the present disclosure, there is provided an insulated building envelope for use in a building energy system comprising: at least in part one or more vacuum insulation panels; wherein said building energy system comprises: a building enclosure having an interior and exterior, and comprising: an insulated building envelope that incorporates at least one fenestration assembly; an integrated mechanical system that provides heating and cooling for various functions, and comprises: a cold thermal storage tank; a hot thermal storage tank; and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank; an air stratified ventilation system comprising at least one upper exhaust outlet and at least one lower supply intake that connect to the exterior of the building enclosure, wherein said upper exhaust outlet incorporates a heat exchanger that recovers heat from outgoing air, and wherein said heat exchanger is connected to the cold thermal storage tank of the integrated mechanical system; wherein energy performance of said at least one fenestration assembly may vary or be automatically controlled such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with a further embodiment of the present disclosure, there is provided a central controller for use in a building energy system wherein said central controller controls operation of an integrated mechanical system and is linked to an electrical supply grid such that the integrated mechanical system may be operated in a manner that reduces at least one of electrical use or peak load demand; and said building energy system comprises: a building enclosure having an interior and exterior, and comprising: an insulated building envelope that incorporates at least one fenestration assembly; the integrated mechanical system that provides heating and cooling for various functions, and comprises: a cold thermal storage tank; a hot thermal storage tank; and a heat pump that transfers heat from the cold thermal storage tank to the hot thermal storage tank; an air stratified ventilation system comprising at least one upper exhaust outlet and at least one lower supply intake that connect to the exterior of the building enclosure, wherein said upper exhaust outlet incorporates a heat exchanger that recovers heat from outgoing air, and wherein said heat exchanger is connected to the cold thermal storage tank of the integrated mechanical system; wherein energy performance of said at least one fenestration assembly may vary or be automatically controlled such that the heating and cooling loads of the integrated mechanical system are at least partially balanced.
In accordance with a further embodiment of the present disclosure, the central controller is linked to an electrical supply grid such that the integrated mechanical system may be operated in a manner that reduces at least one of electrical use or peak load demand.
The following is a description by way of example of certain embodiments of the present invention, reference being made to the accompanying drawings, in which:
Referring to the drawings,
The two story building enclosure 15 incorporates a central space 16 and perimeter rooms 17. The building enclosure 15 is typically a residential building, although other building types with similar floor plans are also appropriate with a key requirement being a centralized circulation space 16. Typically, common walls 26, 27 are positioned between the central space 16 and the perimeter rooms 17. Located within the central space 16 is an open staircase 28 that links the upper two levels 13, 14 of the building enclosure 15. Interior doors 30 are positioned between the central space 16 and the perimeter rooms 17.
Surrounding the building enclosure 15 is a building envelope 18 that consists of exterior masonry walls 20, roof (not shown) and basement floors (not shown). Additional insulation (not shown) is retrofitted to the building envelope and a largely continuous inner air barrier 19 is formed within the building envelope 18. The exterior walls 20 are constructed from solid masonry and because it is important that the exterior heritage appearance is retained, additional insulation (not shown) is retrofitted to the interior face of the wall 20. Depending on the winter design temperature conditions, the combined R-value of the retrofitted insulating external walls is R-15 minimum and preferably R-40 or higher. As detailed in
The exterior walls 20 incorporate perimeter windows 21 that are typically single glazed. To improve energy efficiency, various energy saving devices (not shown) are retrofitted to the perimeter windows 21. Depending on the winter design temperature conditions, the combined center-of-glass R-value of the upgraded perimeter windows 21 is R-6 minimum and preferably R-20 or higher. As detailed in
By radically upgrading the insulating performance and air-tightness of the building envelope 18, there is then a need to also retrofit a ventilation system in order to provide for adequate air quality. As detailed in
During the cooling season, the incoming air 45 is further cooled and dehumidified by means of a second liquid-to-air heat exchanger 54 with a cooling coil being connected to a cold thermal storage tank (not shown). To ensure fast and effective dehumidification, the incoming air 45 is generally cooled below comfort conditions and a third liquid-to air heat exchanger 57 is used to heat the incoming air back to a temperature two or three degrees below the desired comfort set point temperature. During heating season, the pre-heated incoming air 45 is further heated by means of the third liquid-to-air heat exchanger 57 that also heats the air to a temperature two or three degrees below the desired set point temperature.
Through buoyancy and stack effects, the incoming ventilation supply air shown by arrows 37 rises through the building and is exhausted through the major exhaust outlet 36. During the cold winter months when there is a large temperature difference between the incoming and outgoing air, the ventilation stack effect is considerable and there is no need for mechanical fans to provide for adequate ventilation air supply within the perimeter rooms 17. Small diameter vertical ducts 33, 34, 35 (see
For each perimeter room 17, ventilation supply air 37 enters through the lower vents (not shown) at a low velocity and at a temperature only slightly below the desired room temperature. The cooler supply air displaces the warmer room air creating a zone of fresh air at the occupied level. Heat and contaminants (shown by arrow 55) produced by the room occupants and their activities rise to the ceiling 43. The polluted air, as shown by arrows 44, is then fully exhausted from the perimeter room 17 through the upper vents 42 that are connected to the major exhaust air outlet 36. During the heating season, a fourth air-to-liquid heat exchanger 60 is used to recover heat from the exhaust air. As described in
Particularly in the swing seasons, natural ventilation is not sufficient to provide for adequate air quality and a first motorized blower or fan 58 is located in the major exhaust air duct 56 that is selectively operated to provide for higher ventilation levels. To provide for generally balanced air pressure conditions within the building enclosure 15, a second motorized fan 59 is used in tandem with the first motorized fan 58 and this second supply air fan 59 is located within the major supply air duct 48.
To improve the insulating performance of the masonry wall 20 and so that the exterior appearance is not altered, additional insulation 24 is added to the interior side 23 of the masonry wall 20 (See
The thin profile vacuum insulating panels (VIPs) 61 are typically manufactured from an insulating flat sheet of matrix material 64 that is packaged in a metalized multilayer barrier film material 65. The matrix material 64 can be made from various insulating materials with the preferred material being fumed silica. Compared to other matrix materials, the fumed silica has the advantage that there is no need to incorporate additional desiccant and getter materials. A developmental product using fumed silica is manufactured by Dow Corning and the company predicts that after 30 years, the product will retain more than 80 percent of its initial R-35 insulating performance.
Particularly for masonry walls 20 constructed from field stone, the wall dimensions are irregular and this means that the required VIP sizes are non-standard. Consequently, there would be major logistical and production problems if these non-standard VIPs 61 were manufactured in a single centralized plant. One option is for the VIP manufacturer to produce a range of standard size VIPs 61 and then to ship these standard size VIPs 61 to regional manufacturers who produce the custom sized interior panel assemblies 63. The standard size VIP's 61 are sandwiched between two galvanized steel sheets 66,67 which are cut to size to fit the panel opening. Additional foam insulation 70 is added as required to fill any gaps in the custom panel assembly 63. To provide for the required structural stiffness, the VIPs 61 are adhered to the galvanized metal sheets 66, 67. Various adhesives can be used with one option being acrylic pressure sensitive adhesive. A second preferred option is to use dabs of silicone sealant located about 2 to 3 inches apart and this provides for assured long term durability. A third structural stressed skin 71 is located apart from the VIP/galvanized steel sub assembly 69 and the gap between the second 67 and third stressed skin 71 is typically filled with insulating foam material 70. As well as providing structural continuity, the foam material 70 also protects the VIP's 61 from accidental damage.
The prefabricated stressed skin panel assemblies 63 are self supporting and span between the floor 22 and ceiling 43 of the perimeter room 17. The perimeter edges of the stressed skin panel assemblies 63 are shown by the dotted line 72. The panel assemblies 63 are positioned away from the masonry wall 20 creating a continuous cavity 52 about a ½ inch in width. As described in
After the existing lath-and-plaster assembly (not shown) is removed, the obvious cracks and imperfections on the interior surface 23 of the masonry wall 20 are filled with a lime mortar mix. The interior surface 23 of the masonry wall 20 is then sealed with a moisture permeable air barrier coating 25 with one preferred product being Perm-A-Barrier manufactured by W.R. Grace & Co. The stressed skin panels 63 are then installed with the joints 51 between the stressed skin VIP panel assemblies 63 being carefully sealed and taped. The joints 51 between the VIP panel assemblies 63 and the adjacent structure (not shown) are also sealed, creating a continuous inner vapor/air barrier 19.
After the stressed skin panels 63 are installed, a special gypsum board sheet 62 is attached to the outer galvanized steel sheet 71 using self-taping screws. Marketed under the name of Blueboard™, the special plaster board sheeting 62 is then finished with a plaster coating about an ⅛ inch in thickness. The traditional wood trim is then replaced and for the casual observer, it would be difficult to notice that the building's interior appearance had been modified. The width of the installed assembly from the inside masonry wall surface 23 to the interior plaster surface 75 is about 4½ inches. In comparison, the typical width of a traditional lath-and-plaster sub-assembly (not shown) from the inside masonry wall 23 to the finished plaster surface 75 is about 3½ inches. Although the interior room dimensions are slightly reduced, the insulating wall performance is radically improved to about R-50 depending on the type of insulating foam used in the panel assembly 63.
One consequence of radically upgrading the insulating performance of the exterior masonry wall 20 is that it creates a need to also radically upgrade the energy efficiency of the perimeter windows 21 as typically, the insulating performance of a traditional, single glazed, wood window 21 is only R-1. One preferred way of upgrading window energy efficiency is to install a moveable vacuum insulating glass unit (VIG) 77 located on the interior side 79 of the perimeter window 21. The VIG perimeter edge 78 overlaps the perimeter edge 72 of the VIP stressed skin panel assemblies 63 by about 3 inches. The VIG unit 77 slides horizontally and in the open or parked position, the unit is located in a hidden wall pocket 80 as shown by the dotted line 81.
The hidden wall pocket 80 within the stressed skin panel assembly 63 can be formed using wood or rolled steel studs 82 that are conventionally used for fabricating pocket door assemblies. Alternatively, the pocket 80 can be formed by adding a fourth stressed skin sheet (not shown) sized to overlap the hidden pocket 80 and incorporating bent steel edges. By using insulating spray foam, the fourth stressed skin is bonded to the third interior stressed skin 71 so that the hidden pocket 80 becomes an integral part of the stressed skin panel assembly 63. The advantage of the integrated pocket panel assembly is that the assembly 63 is easier to remove and replace if the VIP panels 61 need replacing.
As shown in
Although the insulating performance of the VIG center-of-glass 90 can be as high as R-15, the performance of the VIG perimeter edge-of-glass 91 is poor, typically less than R-1. By overlapping the VIP stressed skin panel assembly 63 and by installing a removable insulating trim frame 92 over the VIG perimeter edge-of-glass 91, the conductive VIG edges 78 are buried within insulating edge pockets 89 so that perimeter heat loss is substantially reduced. To maintain the interior appearance of the heritage window 21, the existing window surround trim 93 is first removed and is then reattached and supported by an insulating sub frame 94.
As shown in
There are gaps 97, 98 between the moveable VIG unit 77 and the perimeter edges 72 of the VIP stressed skin panel assemblies 63 and also between the VIG unit 77 and the insulating sub frame 94, and these gaps 97, 98 are weak links in the high-R insulating interior retrofit. Twin foam rubber insulating weather seals 99 are used to seal these gaps 97, 98 and these weather seals incorporate flock tapes 100 that provide for an effective seal at the contact surfaces and also allow the VIG unit 77 to move smoothly back and forth with minimal friction. Using a detachable suction handle (not shown), the VIG unit 77 can be manually moved back and forth or preferably, the opening and closing operation is motorized allowing for automated control and the optimization of window energy performance.
To protect the VIG perimeter edge seals 78 from damage, sealant (not shown) can be applied in the outward facing perimeter channel with silicone sealant being the preferred material. The perimeter edge seals 78 of the VIG units 77 can be further protected from accidental damage by means of a sponge foam rubber seals (not shown).
As shown in
As shown in
As shown in
In addition to retrofit construction, the high-R insulating combination of VIP and VIG technologies can also be used advantageously for new construction.
The outer stud wall 113 is constructed using either conventional framing techniques or because the VIP stressed skin panel assemblies 63 need to be occasionally replaced, typically every 30 to 40 years. The outer stud wall 113 can be fabricated as a removable stressed skin panel assembly (not shown) that is top and bottom supported. Using conventional pocket door framing techniques, a hidden wall pocket 80 is created between the outer side 117 of the VIP panel assemblies and the outer stud wall 113. Flashing 118 and other details are incorporated into the outer stud wall assembly to allow for water drainage. Conventional fiberglass insulating batts 122 are used to insulate the inner and outer stud walls 112, 113 and the combined insulating performance of the double stud wall/VIP assemblies is in excess of R-100.
The double, double VIG fenestration assembly 111 consists of inner and outer VIG units 77, 119 that are top supported by wheeled hangers 95 which run in tracks 96 structurally supported by the framing members (not shown). After the VIG units 77, 119 are hung in position and insulating trim frames 92, 120 are installed and attached to the surrounding structural framing. The insulating trim frames 92, 120 can be manufactured from a variety of different materials with one preferred option being foam-filled pultruded fiberglass profiles which provide for the enhanced stiffness needed to achieve airtight seals around the moveable VIG units 77, 119. As previously described, the preferred weather seal product is a double flexible foam rubber seals 99 that incorporate flock tapes 100. As shown in
As previously described in
a shows the fenestration assembly 111 during winter daytime operation when solar thermal energy is usefully available for heating. To allow for high solar gains, the outer VIG unit 119 is in a closed position and the inner VIG unit 77 is in a open or parked position. The outer VIG unit 119 incorporates a solar control low-e coating 105 that is located on glass surface three 87 as numbered from the exterior. Because the solar control low-e coating 105 limits the transfer of near infra-red solar radiation, the inner glass sheet 84 heats up and as there is limited heat transfer back across the vacuum cavity 85, a surprisingly high percentage of the potential solar heat gains 123 are reradiated from glass surface four 106 and enter the room interior to be usefully employed for space heating.
b shows the fenestration assembly 111 during winter night time operation. To provide for maximum insulating performance both the inner and outer VIG units 77,119 are in a closed position. The Venetian blind 102 is also deployed and is in a closed position that effectively creates two additional glazing cavities 124,125. The Venetian blind 102 can optionally feature a low-emissivity finish 126 on the slats 127 and taken together, the combined fenestration assembly 111 provides an overall insulating performance in excess of R-35.
c shows the fenestration assembly 111 during summer night time operation when natural cooling is available and also during swing season operation when natural ventilation is required. To maximize natural ventilation and cooling, the Venetian blind 102 is in a raised position and both the inner and outer VIG units 77, 119 are in an open and parked position.
d shows the fenestration assembly 111 during summer day time operation when air conditioning is required because of high outside air temperatures and humidity levels. To minimize solar gains, the outer VIG unit 119 is an open, parked position and the inner VIG unit 77, is in a closed position. A solar control low-e coating 105 is located on glass surface six 108 of the fenestration assembly 111. The Venetian blind 102 is deployed and the slats 127 angled to directly intercept most of the incoming direct solar radiation 128. The solar control low-e coating 105 prevents further transfer of near infra red solar radiation and even though the outer glass sheet 83 of the inner VIG unit 77 heats up, there is very limited heat transfer across the vacuum cavity 85.
Although VIG units 77, 119 are shown in
In addition to higher overall insulating performance, existing commercially available high-R windows incorporate solar control low-e coatings that typically reduce solar heat gains to less than 30 per cent. In comparison, the double, double fenestration assembly only reduces solar heat gains to about 80 per cent, when only the outer IG is deployed on sunny days during the heating season.
An inexpensive alternative to a double, double fenestration assembly is a single, double or a single, single assembly with the single glass sheet featuring exterior low-e coatings on both glass surfaces. The single, single window assembly is similar to a Pierson slider which is a window type that was popular in Canada during the 1950's. For a single, double fenestration assembly incorporating a simple blind between glass surfaces two and three and with exterior low-coatings on glass surfaces two, three and six, the center-of-glass insulating performance is R-11 when the blind is closed. For a single, single fenestration assembly incorporating a simple blind between glass surfaces two and three and with exterior low-e coatings on glass surfaces two, three and four, the center-of-glass insulating performance is R-7 when the blind is closed.
Specifically,
In the basement floor 138 and attic ceiling 139, the upgraded building envelope 131 can be constructed from conventional insulating materials and as shown in
In order to radically upgrade insulating performance without significantly altering the building's architectural appearance, VIPs 61 are retrofitted to the interior side 23 of the uninsulated stone wall 20. The VIPs 61 are incorporated into a stressed skin panel assembly 63 that spans unsupported between the floor 22 and ceiling 144. The stressed skin panel assemblies 63 are spaced apart from the masonry wall 20 creating narrow cavities 52 that are connected to a lower air supply duct 48 and an upper air exhaust duct 56 which in turn are connected to a major air supply inlet 46 and a major exhaust outlet 36.
Because an airtight barrier 19 is created that surrounds the building enclosure 15, the supply inlet 46 is the only major opening for bringing ventilation air into the building enclosure 15 and the exhaust outlet 36 is the only major opening for removing ventilation air from the building enclosure 15.
As previously described in
Through buoyancy and stack effects, the incoming ventilation supply air as shown by arrows 37 rises through the building and is exhausted through the exhaust outlet 36. Specifically, the air rises from the first floor 13 to the second floor 14 through an open staircase 28. During cold winter months, the ventilation stack effect is considerable and there is no need for mechanical fans to provide for adequate ventilation air supply. In the swing seasons and in the summer when the windows are closed and an air conditioning system is in operation, ventilation stack effect will not be sufficient to provide for adequate air quality. To provide for mechanical ventilation, a first motorized blower or fan 67 is located in the major exhaust air duct 56 that is selectively operated to provide for higher ventilation levels. To provide for generally balanced air pressure conditions within the building enclosure 15, a second motorized fan 59 is used in tandem with the first motorized fan 58 and this second supply air fan 59 is located within the major supply air duct 48.
As previously described in FIGS. 1,2 and 3, ventilation supply air 37 enters the perimeter rooms 21 through lower vents 29 and as shown in
The stratified air ventilation system 133 is integrated with narrow vented wall cavities 52 that are located between the inside surface 79 of the masonry wall 20 and the stressed skin VIP panel assemblies 63. The vented wall cavities 52 are connected to the major air supply inlet 46 and the major exhaust air outlet 36. During the heating season, the incoming cold dry outside air 45 is preheated by the first air-to-liquid heat exchanger 49 before being supplied to the inlet cavity duct 145. During the cooling season, the warm humid incoming air is pre-cooled by the first air-to-liquid heat exchanger 49 and via a duct extension 146, there is the option of dehumidifying and also preheating the incoming air 45 being supplied to the inlet wall cavity duct 145. By supplying low humidity air during both the heating and cooling seasons, the masonry wall 20 can be dried out from the interior eliminating the potential for condensation and related problems. An additional advantage is that there are essentially balanced pressure conditions between the building interior and the vented wall cavity 52 so that even if the sealed joints 51 between the stressed skin VIP panel assemblies 63 are flawed, moist humid interior air is not sucked into the cold wall cavity 52 causing potential condensation problems.
After retrofitting a high-R insulating and airtight envelope 131, the heating and cooling loads are so small that for air quality reasons, it is preferable that heating and cooling inputs are supplied separately from ventilation air. As shown in
For effective removal of polluted air and contaminants 55, it is important that there is no down drafting at the perimeter windows 21 and assuming that there is no perimeter heating, this requires that the insulating performance of the perimeter window 21 is higher than conventional, high performance double-glazed windows (R-4 centre-of-glass). Depending on geographic location and climate, the perimeter windows 21 should have a minimum R-6 center-of-glass performance and even higher in more extreme cold climate locations. Particularly for masonry buildings with thick exterior walls 20 single glazed windows are located close to the exterior wall surface 181 to ensure that rain water is effectively shed away from the masonry wall 20. On the interior side 182, this results in a wide interior sill 183 or shelf where cold air can pool and create potential down drafting problems. One way of eliminating this potential problem is to retrofit an inner double glazing assembly 184 located close the interior wall surface 185.
As previously described in
To optimize heating and cooling performance, the VIG unit 77 and the Venetian blind 102 can be deployed in various ways. Although a specific assembly of component fenestration products is shown in
By retrofitting a high-R building envelope 131 and energy efficient fenestration assemblies 132 with Smart Window component technologies 171, there is the opportunity to take advantage of more cost effective and energy efficient HVAC systems. One preferred strategy is to combine an integrated mechanical system 134 with an air stratified ventilation system 133. The integrated mechanical system consists of a cold thermal storage tank 142, a hot water tank 143 and a heat pump 150 that transfers heat from the cold thermal storage tank 142 to the hot water tank 143. The hot thermal storage tank 143 supplies heat for various operations including: space heating 151, ventilation air preheating in the winter 152 and domestic hot water heating 153, clothes drying 154 all year round. The cold thermal storage tank 142 supplies cooling for various operations, including: space cooling 155, dehumidification 157 in the summer, ventilation air heat recovery 158 and grey water heat recovery 159 in the winter and food refrigeration 160 all year around. The cold thermal storage 142 is an ice slush tank 161 which the heat pump 150 cools, and so by utilizing water as a phase change material, the required tank size is significantly reduced.
Although not shown in
For optimum energy efficient operation of the heat pump operation, there is a need for heating loads to balance cooling loads. If this does not happen, a conventional but comparatively inefficient electrical element 162 located in the hot water tank 143 is used to provide back-up heating. Obviously during the winter months, the heating loads are generally higher and during the summer months, the cooling loads are generally higher. To try and equalize the loads, the first priority is to reduce both winter heating loads and summer cooling loads. Winter heating loads can be reduced by such means as retrofitting a high-R air tight building envelope 131, preheating ventilation air using ground source heat 163, preheating cold water supply using grey water heat recovery 164, supplementary biomass combustion heating on extreme cold days (not shown) etc. Summer cooling loads can be reduced by such measures as pre-cooling of ventilation air 165, exhausting excess bathroom humidity (not shown), eliminating heat gains from food refrigeration 160 etc.
The second priority is to find applications for the excess heating and cooling capacity. In the summer months, the excess heat can be used for pool heating (not shown) or if a desiccant dehumidifier is substituted (not shown), the excess heat can be used for reactivating the desiccant material. In the winter months, the excess cooling capacity is used to recover heat both from the exhaust ventilation air 168 and grey water waste 169. It should be noted that for both heat recovery applications 168, 169 by supplying coolant at near freezing temperatures, both heat exchangers operate at high efficiencies. Also it should be noted that to simplify the schematic drawing, the grey water heat recovery exchanger 159 connected to the cold thermal storage tank 142 is not correctly positioned and should be located after rather than before the grey water heat recovery device 170 for preheating the cold water supply 164.
The third priority is to balance the loads through Smart Window components 171 and as previously described, these Smart Window components 171 include dynamic solar shading, moveable insulation and natural ventilation/cooling. Both in the winter and summer and depending on location, building orientation and window size, Smart Window technologies 171 can potentially reduce both heating and cooling loads by as much as sixty per cent.
To optimize the performance of the building energy system 130, there is a need for a control system 135 and as shown in
The individual room controllers 136 are linked typically by wireless connections 176 to a central controller 137. Major appliances such as the refrigerator 179 and the clothes dryer 180 as well as the other major components of the building energy system are also linked to the central controller 137 by wireless connections 176. As well, the central controller 137 is linked to the Internet 177 and the local electrical utility company 178. Based on weather predictions, sensor measurements and an understanding of the occupant's future activities, the central controller 137 can determine how much heat or cold thermal energy should be stored. Specifically, the controller 137 can determine room by room: first, whether the single, double fenestration assemblies 101 should be open or closed: second, whether the fenestration assembly 101 should be configured to collect or reject solar heat gains 123, and third whether the moveable VIG unit 77 should be closed to reduce heat loss.
Through the automated operation of opening and closing of the VIG unit 77, maximum advantage can be taken of natural ventilation and night cooling 129. One key advantage of combining a stratified air ventilation system 133 with an integrated mechanical system 134 is that in hot, humid climates, the combined system 133, 134 is more efficient in drying out a building than a centralized ducting system. As a result, dry comfort conditions can be more quickly achieved and this allows for more aggressive intermittent use of natural ventilation 129. There are three main reason why the combined system is more efficient in moisture removal. First with a stratified system 133, moist warm polluted air 44 rises to the ceiling and can be efficiently exhausted with room-by-room control. Second with a stratified system 133, there is no air recirculation and all the moist warm polluted air 44 is extracted. Third with an integrated mechanical system 134, only a small heat pump 150 is used but due to the cold thermal storage 142, there is enough cooling capacity for the system to operate in overdrive in the initial start-up period.
By using a small efficient heat pump 150 for both space heating and cooling, the integrated mechanical system 134 provides for a more even seasonal demand for electricity. Also by incorporating both hot 143 and cold thermal storage 142, it is feasible for major electrical consumption to be shed to daily off-peak hours. By separating electrically-powered heating and cooling functions from the other appliance operations, more energy efficient products can be developed for major electrical appliances such as clothes dryers 180 and food refrigerators 179. Also as the required thermal energy can be generated off peak, these new products can be cost effectively operated during peak demand periods. For example, the inconvenience of having to operate a clothes dryer in the middle of the night is unnecessary.
Although
As a result by combining a high-R building envelope 131 and an integrated mechanical system 134, the building enclosure 15 can be both cost effectively heated and cooled using electrical power and compared to using natural gas for heating and electrical power for air conditioning, there is an even seasonal peak demand between summer and winter. Moreover because the integrated mechanical system 134 incorporates both a hot water tank 143 and a cold thermal storage 142, the building energy system 130 can be operated so that daily peak load demands are substantially reduced and advantage can be taken of off-peak power rates.
Alternatively for an off-grid house (not shown) incorporating a high-R building envelope 131, the house is so energy efficient that it can be cost effectively powered using solar photovoltaic s (PV). With an integrated mechanical system 134 and because battery storage is expensive, solar PV (not shown) can be used to operate the heat pump 150 with the PV solar power being thermally stored as either as heat or cold. As well as being used for space heating, cooling and domestic hot water, the heat/cold thermal storage 142, 143 can be used to reduce major appliance loads including food refrigeration 160 and clothes drying 154. Of course with solar PV and an integrated mechanical system 134, there still remains a need for battery storage but the battery size required can be quite significantly reduced.
Numerous modifications, variations and adaptions may be made to the particular embodiments of the invention described above without departing from the scope of the invention which is defined in the claims.
This application is a continuation-in-part of co-pending U.S. Non-Provisional application Ser. No. 12/474,203 entitled Building Energy System filed May 28, 2009. The subject matter of the prior application is incorporated in its entirety herein by reference thereto.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12474203 | May 2009 | US |
| Child | 13572625 | US |
