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A Prefab Passive House in Michigan

Freeland, MI

May 19 2016 By Kate McDonald | 13 comments

General Specs and Team

Location: Freeland, MI
Bedrooms: 3
Bathrooms: 2.5
Living Space : 3234 sqf

Designer: Sedgwick & Ferwerda
Builder: Phoenix Haus
Energy consultant: Bill McDonald

Construction

Foundation: Crawl space with ICFInsulated concrete form. Hollow insulated forms, usually made from expanded polystyrene (EPS), used for building walls (foundation and above-ground); after stacking and stabilizing the forms, the aligned cores are filled with concrete, which provides the wall structure. walls

Foundation insulation: Under the crawl space slab, 12 in. of horizontal EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest. (R-50.8); ICF walls have 2 in. EPS on exterior and 2 in. EPS on interior, plus an additional 6 inches of EPS on the exterior side of the ICF walls; above-grade foam is protected with metal flashing.

Above-grade walls: Factory-built wall panels with 2x12 studs, sheathed on the exterior with 2-in. Agepan fiberboard sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. and on the interior with 5/8-in. OSB; supplemented by an interior 2x4 service cavity. Panel seams are sealed on the interior with Siga Rissan tape, and on the extrerior with Siga Wigluv tape.

Water-resistive barrierSometimes also called the weather-resistive barrier, this layer of any wall assembly is the material interior to the wall cladding that forms a secondary drainage plane for liquid water that makes it past the cladding. This layer can be building paper, housewrap, or even a fluid-applied material.: Siga Majvest with taped seams.

Siding: Horizontal fiber-cement siding.

Wall insulation: 2x12 studs and 2x4 service cavity are both insulated with dense-packed cellulose; fiberboard sheathing provides about R-5; total wall R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. is R-51.

Roof: Factory-built roof panels with 16-inch TJI rafters sheathed on the exterior with 2-inch Agepan fiberboard and on the interior with 3/4-inch OSB, supplemented by a 2x6 interior service cavity; roof panels are supported by a glulam structural ridge beam.

Roof insulation: 16-inch rafters and 2x6 interior service cavity are both insulated with dense-packed cellulose (R-71).

Roofing: Exposed-fastener steel roofing over Siga Majcoat roofing underlayment.

Windows: Intus Eforte vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). tilt/turns with triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.; U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. = 0.15.

Doors: Glazed vinyl doors from Intus; U-factor = 0.16.

Space heating and cooling: Two Mitsubishi MSZ-FE09 minisplits.

Domestic hot water: Stiebel Eltron Accelera 300 heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. .

Below Grade Foundation: R-50.7.

Mechanical ventilation: Zehnder Comfo 550 ERV.

Domestic hot water: Stiebel Eltron heat-pump water heater.

Energy

Space heating demand: 4.46 kBTU/(ft2-yr).

Specific primary energy demand: 15.8 kBTU/(ft2-yr).

Design space heat load: 12,441 BTU/h.

Blower-door test results: 0.6 ach50.

The A-Haus was assembled with pre-insulated wall and roof panels

This single-family home, nicknamed the “A-Haus,” is the first house in Michigan to be certified by the Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. Institute U.S. (PHIUS). The striking building is situated on nearly three acres of rural land, bordered by woods and farm fields, in Freeland, Michigan. (To read about a similar project, see the GBAGreenBuildingAdvisor.com article, “Michigan Gets Its First Passivhaus.”)

Lessons Learned

Shipping vertically
On this home, all panels were shipped horizontally or (using industry jargon) “flat packed.” This proved cumbersome and time-consuming — a wide load permit was necessary, slight damage was inevitable during shipping, and the crane operator’s time was not used well. However, it proved to be a great learning opportunity. To fix this, Phoenix Haus now ships everything vertically via a specialized German trailering system. The Germans really do have it nailed down!

Design is everything
Spending enough time during the onset of the project and working with experienced architects, especially those trained in Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. principles, really means a world of difference when it’s time for construction. These efforts in theory and concept translate to a very well thought-out and well-engineered building. Case in point: window details were severely lacking on this house and a solution for flashing and trim work had to be worked out on-site.

A clearer solution for mechanical systems is desired
Most residential HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. contractors, especially in the U.S., still use a “cut & paste” approach when it comes to deciding which heating, cooling, ventilation, and hot water equipment to install. I regret not installing a pre-heat ground loop for the Zehnder ERV(ERV). The part of a balanced ventilation system that captures water vapor and heat from one airstream to condition another. In cold climates, water vapor captured from the outgoing airstream by ERVs can humidify incoming air. In hot-humid climates, ERVs can help maintain (but not reduce) the interior relative humidity as outside air is conditioned by the ERV. fresh air intake — this would have reduced our pre-heat function substantially, especially for our cold climate. Also, I’m excited to see what manufacturers are now designing for the U.S. market when it comes to units that combine heating and cooling with energy recovery. The CERV by Build Equinox seems to be the closest right now.


Kate McDonald

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A Pretty Good House in Southern California

Big Bear Lake, CA

May 2 2016 By Stu Turner | 7 comments

General Specs

Location: Big Bear Lake, CA
Bedrooms: 3
Bathrooms: 2.5
Living Space : 2258 sqf
Cost (USD/sq. ft.): $107/sqf

Cost per square foot excludes the PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system and all soft costs, and includes the 286-square-foot garage.

Construction

Foundation: Perimeter frost walls and slab on grade.

Foundation insulation: Horizontal layer of 6-in. EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest. under slab (R-25), with 2 in. of vertical EPS (R-8) at slab perimeter.

Above-grade walls: Double-stud walls (total thickness, 9 in.) with OSB sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. .

Above-grade wall insulation: 3.5 inches of open-cell spray foam and 5.5 inches of mineral wool (totaling R-34)

Siding: Fiber-cement and stone veneer.

Roof construction: Raised-heel scissors trusses, OSB sheathing, asphalt shingles.

Roof insulation: 18 in. (R-60) of blown-in cellulose.

Windows: Pella 350 windows with triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.; U-factors range from 0.18 to 0.26.

Domestic hot water: Navien 199,000 BTUBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules. gas-fired condensing tankless water heater (Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners., 0.97 EF(EF). Efficiency measure for rating the energy performance of dishwashers, clothes washers, water heaters, and certain other appliances. The higher the energy factor, the greater the efficiency. In some appliances EF reflects the percentage of energy going into the appliance that is turned into useful energy.).

Mechanical ventilation: Exhaust-only system complying with ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant..

Space heating: Two 12,000 BTU/h Mitsubishi Mr. Slim Hyperheat ductless minisplits.

Fire safety: Residential fire sprinkler system, all windows have tempered glass, non-ember admitting attic vents, fire-resistant exterior materials.

Energy

Blower door test results: 1.8 ach50

HERS Index: 53 (without PV), based on California’s 2008 Title 24 Energy Code (in effect until July 2014).

Photovoltaic system rated at 5 kW.

100% LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. lighting (except for 2 accent fixtures)

Water Efficiency

Low-flow water fixtures, 1.28 GPFGallons per flush. Measurement of water use in toilets. Since 1992, toilets sold in the United States have been restricted to 1.6 gpf or less. The standard for high-efficiency toilets (HETs) is 1.28 gpf. toilets, no outside irrigation system (100% native landscaping + gravel).

Indoor Air Quality

All paints and adhesives are low-VOC.

All furniture and cabinets are formaldehyde-free.

No carpeting; the upstairs flooring is wood laminate and downstairs flooring is tile.

A high-performance design for the mountains above Los Angeles

A few years into the housing bust, I started shopping around for a cabin to use as a getaway and vacation rental. I live in San Diego and I set my sights on the resort town of Big Bear Lake, in the San Bernardino mountains northeast of Los Angeles. Just 2½ hours away, it was a place where my family and I had spent many weekends skiing, snowboarding, mountain biking, and fishing.

Lessons Learned

Exhaust fans. Although I think the constant pressure exhaust-only fan from Conservation Technologies is a very elegant system, if I did it over again, I would go with something simpler like Panasonic WhisperQuiet exhaust fans in each bathroom. The Conservation Technologies fan required a lot of ducting and is not as quiet as I had hoped. Although it is rated at only 55 decibels, I had to really work on isolating the fan from the mounting and the ducting to get the noise to where it was barely noticeable through an insulated wall. But I think a bigger issue with the fan is that it is such a specialized product, what happens when it needs to be serviced or replaced? If I had used standard bath fans, that would not be an issue. I doubt any HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. companies in Big Bear would touch my “crazy” inline Swedish fan system.

Mysterious air leaks. My air leakage rate (1.8 ach50) came in a lot higher than I had hoped for. At some point I would love to do some follow-up testing to try to figure out where the leakage points are. I don’t think that the air leakage has impacted my performance very much, since I am using an exhaust-only ventilationMechanical ventilation system in which one or more fans are used to exhaust air from a house and make-up air is supplied passively. Exhaust-only ventilation creates slight depressurization of the home; its impact on vented gas appliances should be considered. system that (hopefully) results in a negatively pressured interior with very little infiltration. I suspect that there are leaks at my sliding windows and my sliding glass door, as these are generally more leaky than awning windows. Another factor is the number of exterior doors; I have four but I probably could have made the house work with two.

I should have specified Zip sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . Another thing I would have changed is my air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both. and insulation choices. Seeing all the trimmed-off foam being packed up in trash bags and hauled away seemed like a sickening waste. I would have been better off using Zip sheathing as my air barrier, and some kind of cellulose (I have since found a contractor who installs damp-spray cellulose) or 100% rock wool as my wall insulation.

I should have included energy monitoring equipment. I wish I had invested in a simple energy monitoring system. I am looking to install one before next winter, so I can at least track the energy use of my minisplits.

Minisplits are fairly quiet, but have some noticeable sound. The minisplit indoor units are extremely quiet and unassuming. The outside fan coils are also very quiet, if you are standing right next to them. But because my exterior units were hung on the exterior wall, I do notice some sound vibrations through the wall when the exterior units are really working. So I can see the wisdom of mounting the exterior units on a concrete pad not attached to the house.

Stu Turner, M.S. Architecture, is an occasional environmental science T.A. at the NewSchool of Architecture + Design. He is also a member of the residential committee of the San Diego chapter of the USGBCUnited States Green Building Council (USGBC). Organization devoted to promoting and certifying green buildings. USGBC created the LEED rating systems..


Stu Turner

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Large Connecticut Home is ‘Zero-Energy-Ready’

Climate Zone 5A, Derby, CT

Jun 11 2015 By | 16 comments

General Specs and Team

Location: Climate Zone 5A, Derby, CT
Bedrooms: 4
Bathrooms: 2.5
Living Space : 4456 sqf

Builder: Mark Nuzzolo, Woodbridge, CT, Brookside Development

Rater: Steven Winter Associates, Matt Slattery

Construction

Foundation: Conditioned basement with R-10 foil-faced rigid insulation from top of wall to 3 ft. below grade; no horizontal insulation under the slab.

Walls: 1 inch (R-6.5) polyisoPolyisocyanurate foam is usually sold with aluminum foil facings. With an R-value of 6 to 6.5 per inch, it is the best insulator and most expensive of the three types of rigid foam. Foil-faced polyisocyanurate is almost impermeable to water vapor; a 1-in.-thick foil-faced board has a permeance of 0.05 perm. While polyisocyanurate was formerly manufactured using HCFCs as blowing agents, U.S. manufacturers have now switched to pentane. Pentane does not damage the earth’s ozone layer, although it may contribute to smog. on exterior side of OSB sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. ; 2x4 16-in. o.c. walls with R-18 flash and batt insulationInsulation, usually of fiberglass or mineral wool and often faced with paper, typically installed between studs in walls and between joists in ceiling cavities. Correct installation is crucial to performance. ; vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). siding.

Windows: Vinyl windows with double-pane, argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows. -filled, low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.; U=0.28, SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.=0.30; basement U=0.46, SHGC=0.61.

Attic: R-68 (19-in.) of cellulose on attic floor; R-50 of closed-cell spray foam in cathedral ceilings.

Heating and cooling: 2-ton air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps. (HSPF 8, 14 SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. ); 96 AFUEAnnual Fuel Utilization Efficiency. Widely-used measure of the fuel efficiency of a heating system that accounts for start-up, cool-down, and other operating losses that occur during real-life operation. AFUE is always lower than combustion efficiency. Furnaces sold in the United States must have a minimum AFUE of 78%. High ratings indicate more efficient equipment. gas furnace; ducts inside, MERV 10 filter

Domestic hot water: Tankless gas; EF(EF). Efficiency measure for rating the energy performance of dishwashers, clothes washers, water heaters, and certain other appliances. The higher the energy factor, the greater the efficiency. In some appliances EF reflects the percentage of energy going into the appliance that is turned into useful energy. 0.92

Mechanical ventilation system: 90 cfm exhaust-only system that meets ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant..

Lighting: 10% LED; 90% CFLCompact fluorescent lamp. Fluorescent lightbulb in which the tube is folded or twisted into a spiral to concentrate the light output. CFLs are typically three to four times as efficient as incandescent lightbulbs, and last eight to ten times as long. CFLs combine the efficiency of fluorescent light with the convenience of an Edison or screw-in base, and new types have been developed that better mimic the light quality of incandescents. Not all CFLs can be dimmed, and frequent on-off cycling can shorten their life. Concerns have been raised over the mercury content of CFLs, and though they have been deemed safe, proper recycling and disposal is encouraged. ; daylight sensor on exterior lamp.

Appliances: Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. refrigerator and dishwasher

Blower-door results: 2.03 ach50

Energy

HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index: 45

Projected annual energy cost savings: $1,730

Projected annual utility costs: $2,110

Annual Energy Savings: 6,319 kWh, 654 therms gas

Solar: House is pre-wired for a future PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system and plumbed for a future solar thermal system.

Water Efficiency

EPA WaterSenseProgram developed and administered by the U.S. Environmental Protection Agency to promote and label water-efficient plumbing fixtures. fixtures

Storm water management during and after construction; invasive species removed; rain garden designed to accept all runoff from home; conservation easement planned.

Certification

DOEUnited States Department of Energy. Zero Energy Ready Home Program

EPA Indoor airPLUS

2013 Connecticut Zero Energy

NAHBNational Association of Home Builders, which awards a Model Green Home Certification. National Green Building StandardNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. , whole development

The builder says that the incremental cost of the energy-efficiency features was only $6,000 more than minimal compliance with the the 2009 code

Builder Mark Nuzzolo of Brookside Development has energy savings all sewn up at his new development, Singer Village in Derby, Connecticut. The high-performance homes are located on land surrounding the historic Singer House, once home of the granddaughter of Isaac Merritt Singer, founder of Singer Sewing Machines.

Lessons Learned

Mark Nuzzolo says that building highly energy-efficient homes requires some homework, teaching ability and collaboration.

"The first hurdle to overcome is gaining the science knowledge which enables you to teach. Take a building science course, lecture, read a lot of articles. Do it more than once as it takes time to absorb. I am still learning," said Nuzzolo.

"Once you acquire the knowledge, you must commit to a strategy. Do you want to get to zero at any cost, or do you want to reach the point of diminishing returns? Either way, you must team up with a competent, experienced, and knowledgeable rater.

"After committing to a whole-house strategy, you are able to seek supply chains and subcontractors and teach, teach, teach. Also, measure everything to determine value and effectiveness," he said.

Working to high energy standards can be frustrating because the code and knowledge lags behind cutting-edge technology.

"The whole concept of green building is to reduce the demand which enables you to use fewer resources to satisfy the demand. Most challenging is saving the money and resources after lowering the demand. The industry workers beginning with engineers right down to the HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. mechanics force you to design to current standards, partly because the codes and standards lag and partly because they have little or no experience with high performance building and lack confidence," said Nuzzolo.

"I have been doing this for some years now, and I am content with my current systems. However, technology is changing every day. You must keep pace," he added.

The benefits of green building still suffer from a lack of awareness by both the pubic and the building industry.

"This is the next biggest or maybe even the biggest challenge. Builders, realtors, appraisers and customers have very little experience with high-performance homes and therefore cannot place a value on it. The sales force needs to be very educated and passionate and demonstrative. In order to get people's attention, we have guaranteed the energy costs," he said.

"Our economy (in Connecticut) has severely lagged the nation, we have had an exodus of employers and households. We have a large amount of foreclosures and short sales which have kept prices low. Development costs, building costs, and lack of demand has kept new homes at depressed levels. It is very difficult to obtain commensurate appraisals and there is therefore little incentive to add costs to a home," said Nuzzolo.


Courtesy of the U.S. Department of Energy

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Denver Developer Focuses on Zero-Energy Homes

Denver, CO

May 28 2015 By | 1 comments

General Specs and Team

Location: Denver, CO
Bedrooms: 3
Bathrooms: 2.5
Living Space : 2115 sqf

Builder: Bill Rectanus, New Town Builders

Energy consultants:Peter Oberhammer, EnergyLogic, Inc.

Construction

Foundation: Conditioned basement with R-19 interior wall insulation

Wall construction: Double-stud 2x4 walls, advanced-framed, with 9.5 inches blown fiberglass (R-40.7)

Windows: Double-pane, low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor., vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate).-framed, U=0.25, SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.=0.27

Roof: Vented attic framed with 14-inch raised-heel trusses

Attic insulation: R-50 blown-in fiberglass attic insulation

Energy

Air leakage rate: 2.11 ach50

HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index: 38 without PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.; -3 with an 8-kW PV system

Estimated annual energy use: $1,414 without PV, $5 with PV

Actual annual energy use: Unknown

PV arrays are an available option

Space heat and cooling: Air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps., 12.7 HSPF, 19.8 SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. , with forced-air ductwork for distribution; 97.3 AFUEAnnual Fuel Utilization Efficiency. Widely-used measure of the fuel efficiency of a heating system that accounts for start-up, cool-down, and other operating losses that occur during real-life operation. AFUE is always lower than combustion efficiency. Furnaces sold in the United States must have a minimum AFUE of 78%. High ratings indicate more efficient equipment. gas furnace for backup.

Ventilation: Exhaust-only 15-watt fan rated at 71 cfm

Domestic hot water: 0.947 EF(EF). Efficiency measure for rating the energy performance of dishwashers, clothes washers, water heaters, and certain other appliances. The higher the energy factor, the greater the efficiency. In some appliances EF reflects the percentage of energy going into the appliance that is turned into useful energy. tankless gas water heater

Lighting: 100% CFLCompact fluorescent lamp. Fluorescent lightbulb in which the tube is folded or twisted into a spiral to concentrate the light output. CFLs are typically three to four times as efficient as incandescent lightbulbs, and last eight to ten times as long. CFLs combine the efficiency of fluorescent light with the convenience of an Edison or screw-in base, and new types have been developed that better mimic the light quality of incandescents. Not all CFLs can be dimmed, and frequent on-off cycling can shorten their life. Concerns have been raised over the mercury content of CFLs, and though they have been deemed safe, proper recycling and disposal is encouraged.

Appliances: All Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners.

Water Efficiency

WaterSenseProgram developed and administered by the U.S. Environmental Protection Agency to promote and label water-efficient plumbing fixtures. compliant fixtures

"Smart" recirculation pump that learns occupants' behavior

Green Materials and Resource Efficiency

Beetle-kill lumber used for all framing lumber

Roadways, bridges, and bike paths use recycled concrete

Certification

DOE Zero Energy Ready

DOE Energy Star

EPA Indoor airPLUS

Double-stud walls effectively reduce thermal bridging

A Denver-area developer, New Town Builders, is aiming to make all of its new homes zero-energy-ready by the end of 2015.

“Our goal is to be 100% U.S. Department of Energy (DOEUnited States Department of Energy.) Zero Energy Ready certified on all of our single-family homes,” said Bill Rectanus, vice president of New Town Builders, which plans to build 150 single-family homes in the Denver metro area in 2015.


Courtesy U.S. Department of Energy

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Modern Dream Home is Energy-Positive

Climate Zone 4C, Seattle, WA

May 21 2015 By | 11 comments

General Specs and Team

Location: Climate Zone 4C, Seattle, WA
Bedrooms: 4
Bathrooms: 3.5
Living Space : 3192 sqf
Cost (USD/sq. ft.): $200/sqf

Builder: Ted Clifton, Jr., TC Legend Homes

Construction

Foundation: Slab on grade with R-28 ICFs at slab edge and R-20 horizontal rigid foam under slab

Walls: 6-inch SIPs rated at R-26

Windows: VinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). windows with low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.. U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. is 0.14; SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. is 0.55

Roof: 12-inch SIPs rated at R-46; standing-seam metal roofing

Siding: Prefinished fiber-cement siding over wrinkled housewrap

Energy

HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index: 42 without PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow., -1 with PV

Projected annual utility costs: $797 without PV, $21 with PV

Annual energy savings compared to code-minimum house: 15,367 kWh without PV, 25,067 kWh with PV

Renewable energy: 9.7-kW PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system

Heating, cooling and domestic hot water: 5-ton air-to-water heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump. with a COPEnergy-efficiency measurement of heating, cooling, and refrigeration appliances. COP is the ratio of useful energy output (heating or cooling) to the amount of energy put in, e.g., a heat pump with a COP of 10 puts out 10 times more energy than it uses. A higher COP indicates a more efficient device . COP is equal to the energy efficiency ratio (EER) divided by 3.415. 4.5 provides hot water for radiant floors and preheats domestic hot water; a 50-gallon electric tank stores water and boosts temperature.

Lighting: 100% LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed.

Appliances: Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. refrigerator, dishwasher, clothes washer

Water Efficiency

Low-flow plumbing fixtures

Indoor Air Quality

Air infiltration rate: 0.97 ach50

Mechanical ventilation: 5.4-watt exhaust fan in laundry runs continuously at 30 cfm to meet ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant. requirements. A 200-cfm supply air fan comes on automatically when the 400-cfm range hood fan is turned on.

Certification

DOE Zero Energy Ready

Northwest Energy Star Certified

EPA Indoor airPLUS

The PV system provides enough electricity for the home and an electric car

A Seattle couple spent two years searching for their dream home before deciding to build a new custom home. They turned to zero-energy-home builder Ted Clifton, Jr., who built them a modern two-story house with a mother-in-law suite and views of Lake Washington from the rooftop deck.

Clifton, the owner of of TC Legend Homes, calls the home a “positive energy home” — one that produces more energy than the home itself consumes. In fact, the home should produce enough electricity to power an electric car with the charging station set up in the garage.

Lessons Learned

Customers need to be convinced that what they see in magazines isn't always great design, says builder Ted Clifton, Jr. In the case of this house, the plans called for shading some of the windows, but the homeowners had a different idea.

“People look at Dwell magazine and see what they want — simple, clean designs — but that doesn’t always work. The original plans drawn by the architect had shading over the windows on the south side. But the homeowners didn't like the look of them so they weren't included. We used high-solar-gain windows, which are good for the winter, but without shading, they allow heat to pass through in the summer. I would prefer to maintain control over those design decisions if I could,” said Clifton.

The project ended up being inspected more often than a conventional home because the city was unfamiliar with some of the processes.

“The city required special inspections every step of the way because we used SIPs. The jurisdiction wasn't as familiar with those construction techniques.”

Clifton has discovered that inspectors, engineers, architects, and yes, builders too, don’t always keep up with the latest innovations from manufacturers. “There is sometimes a disconnect of industrial standards and engineered standards. For example, we learned that we could use thinner nails for much of this project, built with SIPs. Those nails were half the cost of what the plans called for,” he said.

“All of us are responsible to collaborate and on keep up-to-date. We need to provide each other feedback,” he said.

Overall, the building industry hasn’t changed much, he said. “The best place to point a finger is at yourself. Then do it. That’s my mentality. If we want to change it, we all have to step up and pay attention. I learn something new from my entry-level laborer every day. One needs to be open to new ideas and figure out what works best,” said Clifton.


Courtesy of the U.S. Department of Energy

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  1. TC Legend Homes

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New York State Promotes High-Performance Houses

Builders are eligible for an incentive grant of $8,000 for each net-zero energy house they build

Posted on Jun 10 2014 by Scott Gibson

Builders in New York State are now eligible for incentive grants of as much as $8,000 for building net-zero energyProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. houses, according to an announcement by the New York State Energy Research and Development Authority (NYSERDA).


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A Passive Solar Home from the 1980s

Boulder, CO

Feb 25 2014 By Robert Opaluch | 20 comments

General Specs

Location: Boulder, CO
Bedrooms: 3
Bathrooms: 1.5
Living Space : 1480 sqf

Construction

Foundation: Perimeter concrete grade beams surrounding a slab on grade

Vertical insulation at perimeter of foundation: R-45 XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation.

Wall construction: 2x6 studs, 24" o.c.

Wall insulation: R-19 fiberglass batts plus either ½-inch or 1-inch polyisocyanurate on the exterior

Siding: Diagonal 3/4-inch shiplap cedar boards

Ceiling insulation: R-60 fiberglass batts

Windows: Double-glazed sliders, casements, and awnings

Roof framing: Roof trusses (unconditioned attic)

Roofing: Cedar shingles

Domestic hot water: Two batch-type solar thermal collectors with electric resistance backup

Space heating: Passive solar design with electric resistance backup

Energy

5600 heating degree day climate

Renewable energy equipment: Two passive (batch-type) solar thermal collectors

Water Efficiency

Plumbing core was designed to keep pipe runs short

The design of this two-story home in Boulder, Colorado, adhered to timeless passive solar principles

Back in the early 1980s, I built a 1,480-square-foot passive solar home in Boulder, Colorado. There have been substantial improvements in active solar equipment since then. But today’s passive solar design principles are quite similar to the principles preached in the early 1980s. Solar energy provides almost all the winter heating and hot water for this home. The cost savings I achieved by eliminating a central heating system were invested in thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. , additional insulation, and better glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill., so no additional construction costs were incurred compared to conventional construction.

Lessons Learned

What would I do differently next time? In my most recent design for a superinsulated home designed for a cloudy, cold climate, some specifications were different:

• Use even higher insulation levels (R-80+ ceiling, R-40+ walls and floor, R-5 windows)
• Eliminate leaky sliding glass doors and only use triple-pane, low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor., argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows. -filled casement and fixed windows
• Reduce the west-facing glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. to almost none, which is easy with a long east-west axis footprint
• Use updated air and moisture sealing products and techniques
• Install an HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air.
• Don’t use as much thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. for a cloudy climate, especially the concrete block active hot air storage system

Recommendations based on this experience:

• Choose a lot based on location, location, and location — and also solar access and maybe south-facing views
• Orient the home and most of the windows to face south, with a longer east-west axis
• Make the time and investment for massive insulation, tight building materials and practices, and the best quality materials
• Use kitchen layout standards for sufficient space on the sides of the refrigerator, cooktop, sink, and ovens
• Install lots of electrical outlets and convenience features
• Learn to do what you don’t know from experts, books, the Internet, and educational events
• Take the risk and build your own house

Bob Opaluch has had a lifelong interest in energy-efficient homebuilding, passive solar design, and designing and building furniture. He designed and built the passive solar home in Boulder, renovated a house in Massachusetts, and designed and built dozens of furniture pieces for friends and family. He recently led a course in Sustainable Architecture for Lifelong Learning Collaborative, an adult ed organization in Providence, R.I. Bob has degrees in philosophy and applied mathematics from Brown University, and MA and PhD degrees in psychology from UCLA. He was a psychology professor for five years, and a usability and design engineer for 20 years. Bob is a divorced single parent. His son started college this year.


Robert Opaluch

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A Net-Zero Home in Massachusetts

Shelburne, MA

Dec 17 2013 By Charles Bado | 7 comments

General Specs and Team

Location: Shelburne, MA
Bedrooms: 3
Bathrooms: 3
Living Space : 2400 sqf
Cost (USD/sq. ft.): $234/sqf

Cost does not include land.

Designer: Omnibus Designs (Charles Bado)

Builder: Omnibus Designs

Energy consultants: Mike Duclos (DEAP Energy Group) and Peter Talmage, P.E.

Insulation contractor: Bryan Hobbs

Construction

Foundation: Frost wall and slab on grade

Slab insulation: 4 in. horizontal XPS (R-20) under slab and 4 in. vertical XPS at slab perimeter

Frostwall insulation: 2 in. XPS (R-10) on interior of frostwall

Wall construction: Double-stud walls with load-bearing 2x6s, 16 in. o.c., on the exterior and 2x4s, 16 in. o.c., on the interior

Above-grade wall insulation: 2" closed-cell foam spray foam (R-12) on interior side of wall sheathing plus 10" of dense-packed cellulose (R-34) for a total of R-46.

Wall sheathing and air barrier: ½-in. Zip sheathing with all seams taped

Siding: CertainTeed Weatherboard fiber-cement 5 1/2 in. plank siding

Exterior trim: A combination of fiber-cement trim boards, aluminum coilstock, and PVC.

Windows: Wasco Geneo triple-glazed fixed and tilt/turn units, U-0.16, SHGC 0.39 on east & south, SHGC 0.17 on west.

Roof framing: Roof trusses (creating a vented unconditioned attic)

Roof sheathing: 5/8 in. Zip sheathing with all seams taped

Ceiling insulation: 17 in. blown-in cellulose (R-56)

Ceiling air barrier: Tu-tuff polyethylene vapor barrier and continuous ½ in. drywall

Roofing: Englert 24 ga. standing-seam steel.

Energy

Blower-door test: 1.96 ach50

Annual energy use: 6.6 MMBTU (modeled, not measured)

PV system: 30 roof-mounted Bosch C-S- M60 PV modules totaling 7.65 kW; estimated annual output 8,896 kwh; system includes battery backup.

Space heat and cooling: 2 Fujitsu 12RLS2 ductless minisplit heat pumps; heating capacity 16,000 Btu/h; cooling capacity 12,000 Btu/h; supplemented by several 400-wall electric resistance heating panels.

Mechanical ventilation: Zehnder ComfoAir 350 ERV with ComfoFond-L 350 geothermal heat-exchange loop buried under the slab

Domestic hot water: 2 Stiebel Eltron SOL 27 solar thermal collectors connected to a Superstor SSU-80SE 80-gal. storage tank; 4,500-watt electric resistance backup heater.

Water Efficiency

Rainwater collection system

Second-floor bathroom has a hot water recirculating pump on a timer to reduce the amount of water wasted waiting for hot water to reach the faucets

Green Materials and Resource Efficiency

Locally milled black locust lumber was supplied by Blue Sky Farms, Colrain, Mass.

All of the contractors and vendors used for the construction of the home live and have businesses in Franklin County.

With double-stud walls, thick attic insulation, and triple-glazed windows, this home can be heated with just two ductless minisplit units

Before we met, my clients had spent considerable time researching how to build a net-zero home. They read product literature, studied the economics, understood the benefits, and had a pretty intelligent understanding of construction methods and materials. This body of knowledge became the starting point for our discussions and direction.

Lessons Learned

• Open-web floor joists would have allowed for easier installation of ductwork than the I-joists used on this project.

• Ensure adequate spacing (a minimum of 10 inches) between the inside of the gable end walls and the inside face of first joist to allow better access to the band joist.

• It’s best to spray foam the exterior stud bays before building the interior 2x4 stud walls.

• The house ended up with thermal bridging at the perimeter of the slab, especially under exterior door thresholds. A better detail would have included an extension of the slab at door openings and a better thermal break using rigid foam.

• We should have insulated the walls of the basement mechanical room rather than the ceiling.

• We should have performed energy modeling early on during the design phase of the project. Energy modeling wasn’t performed until one month after we had already broken ground; at that point, the plans were mostly fixed. If energy modeling had been performed three months earlier, we would have foreseen the problems associated with locating the mechanical room in the attic.


Charles Bado

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Will the Energy Star Homes Program Survive Version 3?

Sam Rashkin predicted a 50% builder attrition rate — but the losses appear to be even worse

Posted on Nov 6 2013 by Allison A. Bailes III, PhD

Back in 2009, I attended a webinar given by Sam Rashkin, head of the Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. new homes program at the time. (He has since left the EPA for the DOEUnited States Department of Energy..) He explained the changes coming in the program as they prepared for the transition from what we now call Version 2 to the new Version 3.


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  1. Energy Vanguard

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Massachusetts Owner-Builders Complete a Superinsulated Home

This passive solar saltbox is heated by a single ductless minisplit

Posted on May 21 2013 by Spartan Giordano

The superinsulated home that I designed and built for my family of three in Greenfield, Massachusetts has been comfortable for the entire year and serves as an example of successful design for our climate. We moved in to our new home in February 2012.

Modest in size, our home measures 26 feet by 32 feet and has 1,500 square feet of living space, with two full floors plus a partial third floor tucked into the slopes of the cathedral ceiling. In order to decrease the overall volume while maximizing south-facing exposure, we chose a saltbox shape.


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  1. All photos: Spartan Giordano

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