Zero Energy Home Design EDSGN 100 Pennsylvania State University College of Engineering Professor Wallace Catanach Cory Grube Peter Keller Gregory Lerch Chris Vojick February 24, 2011
Abstract Homes are currently one of the largest contributors to an individual's carbon footprint. At the rate most citizens in developed countries are living, the planet is not capable of providing all resources necessary to sustain a population. In addition, their lifestyles are beginning to have a global impact on the world through climate change. The zero energy home research performed in this project is intended to raise awareness about the issue, as well as introduce innovative and green ways to change their lifestyle. Our compiled information was largely built off the research of several existing zero energy homes, as well as collaborative brainstorming for new ways to save electricity. Through the information and ideas that were presented, we produced a scale model of a house that would be completely energy neutral. This includes using an functional design for the layout of the house, as well as the green technology found in the zero energy homes that were researched. Through the implementation of house designs such as this, a large percentage of greenhouse gas emissions can be cut down, lowering the rate of climate change that is currently affecting the world.
Mission Statement The Zero Energy Home project is a way to bring eco-friendly homes to more Americans, in the effort to combat global warming and climate change. Our proposed home's design and prototype were constructed to offset the greatest environmental challenge in our generation.
Customer Statements and Needs Statements # Customer statement Needs statement 1 The house must be zero energy. The building has to maintain zero net energy. 2 The house must look good. The building should have a pleasing design to it 3 The house must be made of renewable resources. 4 The house must be cheap to purchase. 5 The house must have a lot of large windows. 6 The house must be heated and cooled with geothermal. 7 The house must be built in a field with wind potential. The building should be constructed in a sustainable fashion. The building must be reasonably priced for what it offers. The building should utilize natural lighting and heating from the sun. The house should be heated and cooled in an efficient manner. The house should be built in an open space with external sources of renewable energy. 8 The house must be built with an A-frame The house should be built in a way that increases passive light in the house. 9 The house needs to have 2 bedrooms and 2 bathrooms. The house should be capable of housing an average family. The zero energy home project was designed to give the customer exactly what they were looking for in an energy efficient home. They presented us with a list of criteria they wanted to be incorporated into their home. From these customer requirements, we were able to create a set of needs statements which would govern the final design of the project.
External Research Online Research Location (city, state) Cape Cod, Massachusetts House size (floor area in square feet) 6200 Number of floors 2 URL of web site where info is found http://www.zeroenergy.com/p_truro.html Number of occupants Large family Number of bedrooms 7 Type of heating system (forced air, Geothermal Heat Pump hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, Electricity, some natural gas wood, oil, etc.) Size of photovoltaic system (kilowatts) 11.7 kw Solar water heater (yes or no) R-value of wall insulation R-value of ceiling insulation Ventilation air heat recovery (yes or no) Yes Predicted or measured annual energy use Near Net Zero Any other pertinent info Energy can be split into 2 sides of the houses, so when one is not in use they can conserve Location (city, state) Charlotte, Vermont House size (floor area in square feet) 2,800 Number of floors 2 URL of web site where info is found http://www.wbdg.org/references/cs_ch.php Number of occupants Single family Number of bedrooms 2+ Type of heating system (forced air, Geothermal heat pump, GFX system hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, Electricity wood, oil, etc.) Size of photovoltaic system (kilowatts) 10 kw Solar water heater (yes or no) No R-value of wall insulation 40 R-value of ceiling insulation 56 Ventilation air heat recovery (yes or no) Yes Predicted or measured annual energy use Heating 1,865 kwh. Domestic Hot Water 862 kwh. Plus loads, Lighting & equipment 3272 kwh. Total 5,999 kwh Any other pertinent info Wind powers 6622 kwh. All rooms in the house are open to natural lighting. Solar panel of 60x20 is placed east west Above net zero energy Large garden and some chickens Location (city, state) Turners falls, MA
House size (floor area in square feet) 1152 Number of floors 1 URL of web site where info is found http://www.finehomebuilding.com/item/11546/ a-net-zero-energy-home-for-180000 Number of occupants 2 Number of bedrooms 3 Type of heating system (forced air, Air Source Heat Pump hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, Electric wood, oil, etc.) Size of photovoltaic system (kilowatts) Unlisted, but present Solar water heater (yes or no) no R-value of wall insulation r-42 R-value of ceiling insulation r-100 Ventilation air heat recovery (yes or no) no Predicted or measured annual energy use 5275 kwh Any other pertinent info Net Energy Consumption is -1320 kwh/year Floors are insulated: R:30 Has Passive Solar Renewable Location (city, state) Boulder, Colorado House size (floor area in square feet) 3000 Number of floors 2 URL of web site where info is found http://www.eco-structure.com/net-zeroenergy/the-nze-house.aspx Number of occupants 2 Type of heating system (forced air, Solar thermal, forced air? hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, Solar thermal/solar photovoltic wood, oil, etc.) Size of photovoltaic system (kilowatts) 7.2 killowatt Solar water heater (yes or no) yes R-value of wall insulation r-33 R-value of ceiling insulation r-33 Ventilation air heat recovery (yes or no) Yes Predicted or measured annual energy use Net of 0 Any other pertinent info Windows are r-13 insulated Positioned close to public transport and has a home office to reduce transportation cost
Location (city, state) House size (floor area in square feet) Number of floors URL of web site where info is found Number of occupants 2 Number of bedrooms 3 Number of bathrooms 2 Ann Arbor, Michigan 2500 sq ft conditioned space, 1300 sq ft living space 2 plus attic and basement http://web.me.com/kellygrocoff/missionzeroho use/home.html Type of heating system (forced air, Geothermal heating hydronic, radiant floor, heat pump, etc. Type of cooling system Geothermal air conditioning, stack effect airflow Main heating fuel (electricity, natural gas, Geothermal wood, oil, etc.) Size of photovoltaic system (kilowatts) 8.1kW Solar water heater (yes or no) No, geothermal Ventilation air heat recovery (yes or no) Yes Predicted or measured annual energy use 8,389 kwh since February 15, 2011. Energy produced 8,850 kwh since February 15, 2011 Other Motion sensor lighting Location (city, state) House size (floor area in square feet) Number of floors URL of web site where info is found Number of occupants Type of heating system (forced air, hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, wood, oil, etc.) Size of photovoltaic system (kilowatts) Solar water heater (yes or no) Ventilation air heat recovery (yes or no) Predicted or measured annual energy use Predicted or measured annual energy production Any other pertinent info New Paltz, New York. 3000 sq ft 2 plus basement http://www.greenacresnewpaltz.com/pages/perf ormance.html 1+? Unspecified, excluding the owner of the house. Geothermal heat pump Geothermal 10kW No Yes ~8700kWh ~11000kWh Uses air tight insulated concrete forms/expanding foam insulation. Triple-paned windows. Propane range
Every house researched used solar panels. The average wattage of the photovoltaic system was about 9.4 kw. The average energy consumed per house is 7091 kwh. When split into a month by month basis, each month has an average consumption of about 600kWh. Solar systems create differing amounts of electricity based on the hours they spend in the sun. Static panels will achieve the least energy, while panels that move with the sun will make the most energy. The amount of energy that can be produced in a given time is referred to as the solar insolation in kilowatt-hours per square meter per day, which is referred to as sun hours per day in some cases. This figure is used in conjunction with the kw rating of the solar panel to determine the output of a particular panel in a given day or year. The solar insolation is different for every location, due to differing hours of peak sunlight. Most houses researched also contained geothermal heat pumps, which can lower heating costs significantly. The heat pumps can reduce total heating and cooling costs by between 20 to 70 percent, based on current heating and cooling methods in place. The system is very low maintenance and will often last multiple decades. The technology makes use of the ground's constant temperature of between 40-70 degrees Fahrenheit. During winter months, it transfers heat from the ground to the house, and during summer, it transfers heat from the house to the ground. This method of heating and cooling a home has a high installation cost, reaching between $5,000 to $10,000. A typical size home would use a three-ton system, reaching about $7,000 to install. Wind energy can be highly efficient at producing electricity for a house. It has the capability to produce energy at any time of day, unlike solar energy. They often stand more than 100 feet in the air, giving them steady wind flow. Energy costs for a 12,000 kwh house can be reduced by between 50 to 90 percent. However, the installation cost is the highest of any renewable resource at approximately $50,000. As long as wind is about a constant 10mph or higher, a turbine will continuously produce energy, up to 10-15 kw in an hour. Most insulation in these homes had an r-value of above 40 in their walls, and more than r-50 in their ceilings. Proper insulation is necessary to keep any cool air in a house during summer, and warm air in the house during winter. Foams can come in many different forms, such as rolls of fiberglass, cellulose, open and closed-cell spray foam, concrete, recycled materials, and plenty of others. Because an r-value only measures the resistance of heat flow through a material, it cannot be the only factor for determining an insulation. Convection, radiation, and air infiltration must also be taken into consideration. To prevent convection, there must be little-tono gaps between walls. Preventing loss via radiation and air infiltration can be achieved through a dense material being used to insulate. Windows are similar to the insulation in that it needs to have insulating properties. Most windows in zero energy homes are double or triple-paned, which means they consist of a pane of glass, followed by a pocket of air, then another pane of glass. The most efficient windows may be vacuum insulated, which follow the same design of a double-paned window, while removing the gas pocket, leaving only a vacuum. This removes a feature some zero energy home owners prefer however, which is the ability to partially heat a home with natural sunlight. During winter months, a large series of windows can provide a fair amount of heat to the room if it is adequately sunny. Nearly every home researched made use of ventilation air heat recovery. This is a small system that allows air to enter a house without releasing a lot of cool/warm air. It works by mixing incoming air with warm/cool air already in the house with the hot/cold air outside. Using
this system, heating and cooling appliances in the house will not have to struggle to correct an offset in temperature caused by an open window or other source of fresh air. One home researched had a solar water heater installed. This is often used in a similar fashion as solar panels. They sit on a roof or other high-sun area of a property. Cold water flows to the solar box, usually painted black to increase heat absorption. In the box, tubes will wind and bend to fill a large portion of the box. As the water flows through the box, it absorbs heat, and after passing through the box, it goes to a hot water heater, already preheated. This can bring modest cost savings to heating water in a household. The installation cost for a single solar water heater panel is between $2,000 and $3,000. Lighting will be a significant portion of costs in any household. To maintain maximum efficiency, most zero energy homes will make use of compact fluorescent lighting, or even LED lighting, which is regarded as the highest efficiency as of today. For instance, using only LED lighting over incandescent can reduce lighting costs by as much as 80%. They are also more earth friendly in the materials they use. Modern LED's main materials are silicon and various plastics, as opposed to the mercury found in compact fluorescent bulbs. To reduce energy waste, one of the researched homes also used motion sensing technology to turn off lights that were not in use.
Concept Generation The customer needs analysis has presented our group with multiple possibilities for creating a zero energy home for a future homeowner. A wide variety of choices were considered before making the final selections. The possibilities listed below are the span of what we considered for the house s design. The first and most important decision was the energy source powering the home. Considered were the following. Solar Wind Hydroelectric Nuclear Biofuels Natural gas Geothermal The second decision was relative size of the building. Single story Two story Finished basement Unfinished basement 1500 square feet 2500 square feet 3000 square feet Location was the final decision factor in the major design of the house. Bay area (Chesapeake bay) Rural farmland (Lancaster) Metropolitan (Baltimore suburbs)
Concept Selection Power Choice Concepts in consideration Evaluations criteria Solar Wind Hydroelectric Nuclear Biofuels Natural Geothermal gas Energy production + + + + 0 0 + capabilities Cost 0 - - - - - 0 Ease of installation 0 0 - - 0 0 0 Practical in most situations + 0 - - - - + Public acceptance + + 0 - - - + Score Sum +'s 3 2 1 1 0 0 3 Sum 0's 2 3 1 0 2 2 2 Sum -'s 0 0 3 4 3 3 0 Totals Net total 3 1-2 -3-3 -3 3 Overall ranking 1 3 4 5 5 5 1 Continue? Yes No No No No No Yes A concept selection chart was established for the power possibilities listed in concept generation. The highest scoring concepts were chosen based on overall score, and were developed to go into the official home design. The energy production technologies chosen to be implemented were solar and geothermal. Wind power was considered, but ultimately rejected because of its large costs.
House Specifications Concepts in consideration Evaluation Criteria Single story Two story Basement 1500 sq. feet 2500 sq. feet 3000 sq. feet Suited to a 4 person home 0 + 0 - + 0 Environmentally responsible + 0 0 + + - Cost + 0 - + 0 - Convenience - + 0 - + + Customer desire - + 0 - + + Score Sum + s 2 3 0 2 4 2 Sum 0 s 1 2 4 0 1 1 Sum s 2 0 1 3 0 2 Totals Net total 0 3-1 -1 4 0 Overall ranking 3 2 5 5 1 3 Continue? No Yes No No Yes No In the concept selection for house design, the main design aspects to decide between were the relative size of the house, and how many stories it would have. The customer needs have helped play into the concept selection process, based on size-dependent needs they may have. This includes the need for high amounts of passive light and the ability to support an average sized family. As a result, the final design specifications chosen were a two story building sized at 2500 sq. feet. Location Choice The location chosen was Elliot s Island, Maryland. This location offered many natural resources as well as terrific scenery. Being on the Chesapeake Bay, fresh fish will be plentiful, assuming the customer takes the time to catch it. This would cut down on trips to the supermarket, making it focused more on local products such. There are also multiple farms in the area, which would supply more of the locally grown fruits and vegetables a family needs. The bay front location also optimizes the availability of the sun s solar energy. The waterfront location and flat terrain will make wind energy more readily available.
Design The house's main source of power will be generated through the use of solar panels. These panels will be mounted on a rack somewhere in the yard, as opposed to on the roof as in the traditional solar panel system. The average number of sun hours per day (measuring insolation, not daily hours of sunlight. See external research) at our location is approximately 4.5. Our house is expected to use between 7,000 and 8,000kWh of electricity. Therefore, using 100 watt solar panels year round, we will need a solar array of about 5,000 watts. We plan to use 200 watt solar panels, and will need 25 panels. At roughly $450 per panel, the total system cost will be about $11,250, excluding installation costs. The house will feature a solar water heater consisting of 2 panels. This will heat water before it reaches the actual water heater. The cost of implementing these will be about $4,000. A geothermal heat pump will be used as the primary heat and cooling system for the house. Installation of this system will cost about $7,000 dollars, as a three-ton system will be in place. This ensures that adequate heating and cooling will be available for the summer and winter months. The house will have insulated walls and ceilings with r-40 cellulose. Cellulose acts as one of the most efficient insulators for a house, protecting against all 4 types of heat loss. It will be a spray insulation, ensuring it reaches all small cracks of the house. This will also keep it mostly air tight. The total cost of the cellulose is around $2,000, but with installation included, the price could reach $10,000. Because the house is air tight, we want to install a ventilation air heat recovery system. This will bring fresh air into the house in an efficient manner. With fresh air comes a more comfortable house to live in, as well as less indoor pollutants. The total cost for installing this system will be $1,500. The front wall of the house will be primarily made of windows and will face southwest to make use of the mid and late-day sun in heating and lighting. The windows used will be triplepaned, as they are the main source of insulation on this wall. Windows will cost about $250 each. When the sun is not an applicable source of lighting, most of artificial light fixtures will use LED light bulbs to minimize lighting costs. A motion sensing system will be installed in the main rooms of the house to turn off lights in rooms that are uninhabited for more than 20 minutes. The cost of each bulb is $40.
Layout First Floor Plan- Includes Master Bedroom Bathroom Kitchen Lounge/Living Space Simple Dimensions are shown, Approx. ~1350 sq. ft. 3D View with room for editing, depending on customer wants.
Shown with the first floor ceiling and floor. Second Floor Plan- Includes 2 Bedrooms 1 Bathroom Approx. ~1100 sq. ft.
Shows 3D version of the second floor, above the first. Second floor ceiling and flooring added. Note the open entry space.
3D view of both floors combined, with addition of roof. Shaded version, showing some of the terrain and features of the house. (Note that this is not an accurate color scheme.)
Conclusion Overall, Team Seven has put together a highly versatile and successful Zero Energy Home. Located just off the Chesapeake Bay, in Elliot s Island, Maryland, it attracts a wide variety of customers who enjoy the Northeast Region climate, various opportunities for recreations, as well as wildlife. Our two story home appeals to the modern family who is trying to make a difference on our environment. Having features such as the bay front location that optimizes the availability of the sun s solar energy using the houses solar panels will interest these customers. A geothermal heating system as well as the use of energy-saving products (triple paned windows, high R valued insulations, and etc.) would also be major factors. As for the team, we all believe this project was a true eye-opener of the engineering process. We grew in numerous ways from this project and believe our design to be a grand achievement that showcases our true research skills, intuition, and imagination.
References http://www.bigfrogmountain.com/sunhoursperday.html http://www.altestore.com/store/calculators/on_grid_calculator/ http://www.bergey.com/pages/small_wind_turbines_for_homes businesses http://www.cellulose.org/homeowners/whatr-valuemean.php http://blogs.howstuffworks.com/2009/08/06/how-does-a-heat-recovery-ventilator-work/ http://eartheasy.com/live_energyeff_lighting.htm http://www.wholesalesolar.com/starthere/offgrid/offgridcalculator.html