Net-Zero Energy Homes

Definition of a crystallise-postal code nil Home A Net-zero Energy Home (NZEH) is capable of producing, at minimum, an annual turn output of renewable goose egg that is equal to the total fall of its annual polish offd/ purchased free capability from brawn utilities and emits zero net carbon (1). This concept is becoming increasingly popular as people ar becoming more aware of the effects of constructs on the environment. However, to build a net-zero abode, in-depth design considerations to minimize the energy requirements for space kindleing, engine cooling expects and body of water fomenting are required (2).This will result in the to the lowest degree amount of artificial ighting, oestrus, and contrast conditioning to be employ to achieve human comfort level (2). Designing for construct predilection The best build orientation for making in effect(p) use of solar energy is south. Thus, reapning the buildings long axis from east to west and confront withi n 30 degrees of overdue south is strongly recommended (Figure 1). This intromits the house to learn at least 90 percentage of the optimal winter solar commove gain. The buildings south orientation should overly be clear from obstacles to allow unblocked cheer to enter the house (3).Use and Placement of Windows Windows let in sun fallible but trap long-wave radiation, making the indoor temperature rise however, in the absence seizure of sunlight, windows let out considerable amount of het furrow due to their high conductivity. To minimize this effect, selecting windows with special coatings are recommended. Window sizes hold up to be determined carefully because of these unique properties, to balance heat loss and heat gain Net window area should be at least five percent of net floor area with each personal manner or space having one or more windows.Glare screwing frequently become problematic especially through south-facing windows but this bum be prevented by develo pment low-emissivity oated windows. Sloped or horizontal windows such as skylights must be used with caution because they can become study areas of uncontrollable heat loss, overheating, and condensation (3). Controlling Air clinchedness Holes, cracks, floors, walls, ceilings, roofs, and outlets are all supersensitized locations of bank line leakage. Air leakage equals energy leakage because as heated bearing leaks out of the building, the cooler atm outside tends to get sucked into the building.Therefore, tight sealants around all Joints and openings are required. Proper Insulating Techniques An NZEH should also be well(p) insulated around the building envelope to minimize eat transfer. This is achieved by victimisation proper installation of insulation that meets the required R-value (Figure 2). This will not just now minimize the energy loss but also reduce the fate for supplementary heating (3). Providing Ventilation by Mechanical or vivid Systems Ventilation can eith er be mechanically or inbornly provided.Before energy saving became an issue to building occupants and the construction industry, buildings were not as activatetight as they are today and natural ventilation was sufficient. Building occupants could open and close windows for fresh air and continuous entilation was al commissions comprise through the buildings cracks and openings. In airtight buildings, natural ventilation is unreliable because buildings permit fewer openings and cracks for natural air flow and the weather is often likewise cold or rainy for occupants to leave windows open for maintaining adequate congeneric humidity and fresh air circulation (4).One of the mechanical ventilation brasss is the pulsate- moreover trunk, which exhausts air out of the building through an exhaust fan (Figure 3). This can be greet effective and functional provided that the building is airtight enough to run this frame. If the building has cracks that act as an air path, the ai r that gets exhausted out can get sucked back into the building, essentially defeating the purpose of the brass. Also, in humid climates, the exhaust-only arranging tends to cause condensation problems in wall cavities (4).Supply-only ventilation provides fresh air through vents and is extremely effective in providing high indoor air quality when the system of rules is designed and installed according to the building size and specifications. This system can also be combined with a heating system or a humidifying system to suit the occupants needs. This system makes the indoor air pressure higher than the outdoor air pressure, which can work to the occupants payoff if the building is located in intent and humid climates because the positive air pressure will resist the hot and humid pressure from acquiring sucked into the building.However, this is problematic in cold climates because hot and moist indoor air will push against the warm side of the wall cavities, which leads to co ndensation problems (5). An exhaust and supply balanced system is the most ideal system as it can serve all climates. Increasing the Efficiency of Furnace and Air Conditioner Systems twain of the major sources of energy consumption in todays households are the furnace in the winter and the air conditioner (A/C) in the summer. Increasing the quality and efficiency of the furnace and A/C will make some of the greatest returns in cost.Three main factors stick out to healthy and efficient furnace and A/C systems Correct installation by qualified trades. Properly sealed supply and return duct system with approved tapes or mastics to minimize air loss. Continued maintenance end-to-end the lifetime of the furnace and A/C. Where space and cost conditions permit, consider ground-source heat substance echnology as opposed to ENERGY email&160protected furnaces A ground-source heat essence uses the earth or ground water or both as the sources of heat in the winter, and as the sink for heat removed from the alkali in the summer.For this reason, ground- source heat pump systems grant come to be known as earth-energy systems (EESs). Heat is removed from the earth through a liquid, such as ground water or an antifreeze solution, upgraded by the heat pump, and transferred to indoor air. During summer months, the process is reversed heat is extracted from indoor air and transferred to the earth through the ground water or antifreeze solution. A direct-expansion (DX) earth-energy system uses refrigerant in the ground-heat exchanger instead of an antifreeze solution (6). Figure courtly Diagram of a Ground-source Heat Pump Source http//www. ge04va. vt. edu/A3/A3. tm urine Conservation Techniques through competent Water Distribution Systems After heating and cooling, water heating is typically the next largest energy user ot the home because it is necessary for so many domestic activities. Heating water is a large cost especially if a home has out-dated appliances. These next tips can substantially reduce energy consumption simply from water conservation based eating systems. Firstly, a tank slight on-demand water roll of tobacco is advantageous for residences already conserving water, for hot water users comparatively close together, and for communities keep where natural gas is readily operational (Figure 5).Secondly, consider a solar hot water pre-heat system with a parallel piping system for the hot water outlets. Solar energy is the most economical and available energy source and should be utilized to its full potential. The key is to have a knowledgeable solar hot water in fluidation high society perform the installation so proper instillation is achieved. Finally, another cost-effective method to conserve water usage is to install low-flow fixtures. Thousands of gallons of water are wasted everyday because of unnecessary use from high-flow fixtures. Figure The Process of a tank less water heater Source http//kerrygoldplumbing. om/tankl ess-gas-water-heaters Energy Efficient Lighting Fixtures and Lighting Energy efficient lighting fixtures, lighting, and energy efficient appliances meet a standard of reduced energy use rated by ENERGY STARL such appliances consume significantly less energy and water than the standard products. Energy efficient ighting fixtures use approximately 25% the amount of energy of a regular incandescent light fixture (7). Such fixtures are specifically made to work with fluorescent or light-emitting semiconductor diode lights and therefore use less energy. Fluorescent light bulbs consist of a gas-filled tube and magnetic or electronic ballast (8).These bulbs last about 10 times longer (9 years at 3 hours/day) and run cooler than a standard incandescent light bulb (8). Light-emitting diode (LED) lighting consists of a semiconductor diode that converts applied voltage to light (9). LED lighting is available in many different colors and izes, has a lifetime of more than 22 years but still v ery expensive. Energy Efficient Appliances Energy efficient appliances are rated by ENERGY email&160protected and use 10 to 50 percent less energy and water than standard models because these products use advanced technology in their systems (10).These appliances are readily available and can be found at all appliance retailers such as Future Shop, Best corrupt and Sears. Photovoltaic (PV) systems Photovoltaic (PV) systems are comprised of solar cells which convert sunlight straight into electrical energy (11). These cells or semiconductor wafers, installed on the sun-facing ide of buildings, are protected from rain, herald and other inclement weather elements by a glass bed sheet (11). As photons from the sunlight knock electrons into an excited higher energy state, electrical energy is created and captured by the solar cells (11).These solar cells are connected in either series or parallel or both to form PV modules, and in applications the PV modules are arranged in arrays. PV systems produce D power and electricity fed into the electricity grid is converted by inverters to AC power. flow rate PVsystems in use have a 12 to 18 percent intermediate efficiency in converting sunlight to electricity (11). Current developments have achieved an efficiency of 42 percent (11). Residential Applications for PV Systems In residential building, PVsystems are typically installed on roofs or on walls.Roof tiles with integrated PV cells can also be purchased. The use of the residential PV system allows the home to be connected to the electricity grid and surplus power deposited into the grid. To acquire a net-zero energy balance, the destination is to produce as much power from PV systems as you consume from the power grid, so that at the end of the year the homeowner pays short nothing for power. The upfront cost f current PV systems is still relatively high typically costing installed (12).Working Towards a Canadian NZEH Building amount Although there is curren tly no Canadian net-zero energy home building code, work is progressing to lead Canada towards such a building approach. Leading the way is the Net Zero Energy Home Coalition, formed in 2004, whose enactment is to promote alive and available energy efficient and renewable energy technologies to supply residential energy in a sustainable manner in order to minimize the production of greenhouse gases and create healthier, greener communities (1).Comprised of ome builders and developers nifty in applying renewable energy resources to residential building, the Coalition in coalition with the Canada Mortgage and Housing Corporation (CMHC), Natural Resources Canada, Industry Canada, and Environment Canada, aims to fall in a new Canadian NZEH building standard by 2030. To type the viability of NZEHs, the CMHC, supported by the Net-zero Energy Home Coalition, is currently leading a demonstration building project called the Initiative.Fifteen teams across Canada were selected to build demonstration homes using the various techniques discussed in the previous ections. To date, six of the fifteen homes have been perfect in Alberta, Ontario, and Quebec (13). Initiative NZEH Examples New and Old The Alstonvale Net Zero mark is an example of new NZEH construction while the today House bewilder demonstrates how NZEH principles can be economically applied in home renovations. The Alstonvale Net Zero House The Alstonvale Net Zero House (shown on the cover) is a single-family detached house in Hudson, Qubec currently under construction.It features an air-tight, well- insulated building envelope, ample passive heating and cooling techniques hrough large south facing windows, sunscreens, and natural sources of shade (14). An air-to-water pump heating system connected to a PV system provides heated water for the in-floor radiant system and other domestic uses (Figure 9). instead of standard landscaping, a large portion of the site will remain undisturbed and act as a natural habitat tor the topical anesthetic wildlite (14). The Now House Demonstration The Now House Project is a retrofit of a 60-year old home in Toronto, Ontario.The project goal was to demonstrate how home owners and contractors can dramatically mprove the energy efficiency of existing homes with a few relatively simple modifications (15). Energy requirements were reduced by upgrading the insulation, installing low-e, argon-filled windows and energy efficient ENERGY email&160protected appliances, and replacing incandescent lighting with LED lighting (16). Increased energy efficiency and renewable energy production were accomplished through installation of solar hot water panels, a photovoltaic array, and a waste water heat recovery system (16).Figure A Comparison of Energy Consumption in the midst of the Now House and Average Canadian Homes Source http//www. mhc-schl. gc. ca/en/inpr/su/eqho/noho/ upload/Now-House_E-Oct30. pdf Figure 10 on page 8 compares energy consumption rat es between the average Canadian home and the Now House w. Taking into account space heating, water heating, major appliances, inside(prenominal) lighting and space cooling, the Now House will consume only 38 percent as much energy as an average Canadian home (16). From this demonstration, the project shows that NZEH principles are economically viable for renovating as well as older homes across the country.https//happyhealthyhome.files.wordpress.com/2010/05/hhh_report_final.pdfhttps//www.pinterest.com/aimej_r/maison-bioclimatique/http//www.whitebear.k12.mn.us/https//www.energystar.gov/ia/new_homes/features/Appliances_062906.pdfhttps//oee.nrcan.gc.ca/sites/oee.nrcan.gc.ca/files/pdf/publications/infosource/pub/cipec/Managementguide_E.pdfhttps//www.energystar.gov/https//en.wikipedia.org/wiki/Compact_fluorescent_lamphttp//thefreedictionary.com/https//www.energystar.gov/index.cfm?c=appliances.pr_energy_guidehttps//en.wikipedia.org/wiki/Photovoltaicshttp//www.energy.ca.gov/reports/2003- 11-13_500-03-083F.PDFhttps//www.cmhc-schl.gc.ca/en/inpr/su/eqho/ecte/ecte_005.cfmhttps//www.cmhc-schl.gc.ca/https//en.wikipedia.org/wiki/Canada_Mortgage_and_Housing_Corporationhttps//www.cmhc-schl.gc.ca/en/inpr/su/eqho/noho/