Environmental Stewardship Conservation

Transcription

1 Environmental Controls Professor Robert Young Group 1 Environmental Stewardship Conservation Current energy crises have brought to the attention of the general population the significant need to raise awareness about energy conservation. Buildings in the U.S. today consume 72 percent of electricity produced, and account for 55 percent of U.S. natural gas use. They account for about 40 percent of total U.S. energy consumption; these are the factors that we as architects must deal with. In order to conserve energy at the University of Utah Architecture Building we must look to several factors such as: energy efficient window systems, HVAC and natural ventilation, green roof ideas, up to date insulation and electrical systems. In regards to window systems in the architecture building, most of the glazing is single pane glass with no options of shading, opening, or customization for any more or less comfort value. There are many options when considering how we as a school can better both our energy costs and comfort, one of those options lies in making the window systems in the architecture building more accommodating. Within these options there are several different routes to take; one of these lies in inflector systems. These Solar Inflector Systems are products that can be installed in place of the single pane windows we currently have installed. The benefits of the new inflector panes are in the ability to choose what side fits the climate most accurately meaning that the architecture building features mostly a mild climate; therefore, the dark, non-reflective side of the inflector, when facing outward in the heating season, will absorb suns energy and limit heat transfer in into the room, in essence becoming a passive solar collector. Conversely, if installed in a climate in which cool times 1

2 of the year were more permanent than the warm, it will perform as a thermal barrier, keeping your heated room temperature from being cooled against the cold glass. It does this by reflecting your rooms heat away from its surface to contain the heat in the room. How either of these processes work is the process of a metalized coated polyethylene sheet which is laminated to a sheet of carbon granite, then perforated and laminated to a sheet of clear polyester. Applying this certain technique would keep all of the radiant heat, solar heat indoors and reflect damaging UV rays. Another route for conservational issues concerning our windows would be installing an operable louver system. Contrary to the inflector system option, this acts as a shade controlling device that controls certain heat gain and loss which gives the occupants the advantage of an option of either shade or sun; which of course addresses both the comfort issues and also the energy consumption issues. These louvers act as a series of vertical or horizontal shades, attenuating the incident light (reflect, absorb, and diffuse). Horizontal louvers are better in blocking direct solar radiation from higher solar altitudes, while vertical ones are better in lower altitudes. These louvers range in material and size and are more commonly becoming not just an addition to a building, but more of a design decision that designers use to both better the energy consumption and the overall aesthetic value. In a public building the HVAC or Heating, Ventilation, and Air-Conditioning systems play a very large role in the building s energy efficiency, occupant productivity and comfort. For a building to be a high performance building, this system must perform better than a typical system in all aspects. Since HVAC systems generally account for 50% or more of the total energy consumed by a building, this is a category that needs careful attention to design and cannot be overlooked. 2

3 In a typical HVAC system 50% of the total energy use and over 50% of the total system cost is from the distribution systems. These systems are the pumps, ductwork, piping, and fans. Typically 75% of remodeling costs are spent on these distribution systems. Optimization and replacement of these systems is one of the highest priorities when striving to reach the goal of a net zero building. Along with optimization, these systems must be regularly maintained. A strict maintenance plan would greatly increase the longevity of the entire HVAC system. Although HVAC stands for Heating, Ventilation, and Air-Conditioning, a fourth category is equally important. This Category is the controls of the system. The use of occupancy sensors and other similar products would help conserve energy that is used for the HVAC system. These devices use motion sensors or infrared sensors to detect if the building is occupied and changes the load of the HVAC accordingly. This prevents the system from running at full load when people are not present. These simple devices can help save a significant amount of energy since they are automatic and do not rely on people managing the building on their own. With other conservation improvements being made to the building, the size of the HVAC system can be reduced, therefore saving even more energy. Most high performance HVAC systems when combined with these improvements can reduce energy consumption by 30% with a typical payback period of three to seven years. The replacement and optimization of the HVAC system presents an opportunity to look at other natural ways to ventilate the building. Apart from a small percentage of windows in the faculty offices, there are no operable windows, and no control of 3

4 temperature, leaving some regions cold, while others are extremely warm. Because of these inconsistencies massive energy is lost, comfort is compromised, and the air is often stale or stagnate, leading to spreading disease and lack of productivity. Through precedence studies, such as the Lighthouse by Sheppard Robson, and our own Design Build Bluff, we propose solutions to these problems. The origins of wind-catchers can be traced back to Millennia ago, in early traditional Persian architecture to moderate temperature change. Iran has a very large day/night temperature difference, being cool at night to extremely hot in the day. The basic function of a wind catcher is to draw air out of the space by rotating the opening leeward, and thus the air is ushered out via the coanda effect. The use of the vent can be used in reverse as well, if the vent faces toward the wind, air is forced down the shaft, pulling cool air down throughout the building. Basically, a wind-catcher is a vertical void or air well, similar to a chimney, which can be made from any basic material, such as brick or stone. It cuts through the center of the habitable space from the roof to the basement with shuttered apertures that can be opened or closed as needed. Using a wind-catcher in conjunction with operable windows generates a personal weather system, sending cool breezes out from the center of the space, by pulling cold air down from the roof, or dispersing warm winds upward through the structure. The windcatcher can also be used in tandem with underground streams. Air passes over the stream and up through the structure creating a passively cooled space. Activated naturally by gradations in temperature from top to bottom, it is effectually an anticipatory, self regulating air conditioning, using absolutely no energy, and allowing for the replacement of stagnate; virus or bacteria filled stale air, encouraging health and productivity of the 4

5 space s inhabitants. However, if complete passive means are not enough, the windcatchers effects can be amplified by the use of electric fans or a heat recovery system to maintain consistent indoor temperatures, both are still low impact options. If there is no wind the wind-catcher can be used as a solar or thermal chimney. A solar chimney basically gathers heat through its orientation, color, or material, as the air warms inside the chimney convection occurs and causes cool air to be drawn out of the space below without any wind. As Utah is a cold environment half of the year, the design can be reversed by integrating a trombe wall on the south side of the building, providing the advantage of solar heating. The heat gained by the thermal mass of the trombe wall would then be naturally ventilated throughout the spaces of the building via the windcatcher system. The architecture building at the University of Utah is currently dealing with the same issue that many urban areas are facing. There is a scarcity of open space, and the urban areas around us are becoming more condensed; and a direct result of this is the constant worry of air quality. Various cities are starting to look at the use of a green roof (living roofs) to help improve the air quality and use of space in densely populated areas. Green roofs are an upgrade for any building; a green roof creates an aesthetically pleasing roof, creates thermal mass, and retains storm water. Many buildings stand out to the public simply by the use of a green roof. In salt lake alone many people know and have grown to love the Salt Lake City library and the LDS conference center due to their green roofs. By creating a roof garden you often can make a great communal space where people may interact with each other. By having a green roof 5

6 that is accessible to the public\tenants the building would be more user friendly by giving an organic space where people can escape the artificial enclosures where they spend the majority of their day. Another benefit of a green roof is the thermal mass that it creates. A typical roof consists of the structure, insulation, and a moisture membrane. Many of the exterior membranes are black which causes a heat island which contributes more heat to the building. By adding a green roof, the mass of the soil and vegetation insulate the building. This means that the interior side of the roof requires less insulation. Also By having the soil and vegetation these act like a shield for the vapor membrane from the sun s damaging UV rays. By using nature to your advantage a green roof can last longer than a conventional roof that is trying to compete with nature. While the soil and vegetation on a roof helps with air quality and with thermal mass, they also do more than what meets the eye. When it rains the green roof acts like a large sponge. The root systems of the vegetation and the soil help absorb the majority of the precipitation which helps reduce wasteful run off. If the green roof is designed for the local climate then there is no need for an irrigation system. The benefits of a roof garden surpass the disadvantages. The main disadvantage of a roof garden is in order to add a roof garden to an existing building the structural system must be retrofitted in order to support the weight of the soil, vegetation, etc. although the alteration to the existing structure is at times an extensive undertaking, the overall finished product is worth the cost. The architecture building is already equipped with sufficient 6

7 structural integrity to accommodate the additional live load of the green roof, and thus would be a viable proposition to incorporate. Another area in which we, as the consumer, can reduce the amount of energy we use is in our use of electricity from lights and appliances. There are three main categories in which we can conserve energy in terms of electricity used by lighting and appliances. These are: design phase, lamps and appliances, and our practices. The first area is in the initial stages of the development of a building; design phase. If we can, in the beginning stages, begin to incorporate methods of utilizing natural light, and efficient use of electric lights, we can be much more successful in creating buildings that will be more sustainable. In dealing with lighting, there are three classifications of lighting types: ambient, task, and accent lighting. Ambient light is light used to illuminate the entire room to a certain level. Natural day lighting can, in many cases be used as ambient light. Task lighting is the illumination provided for specific tasks. Task lighting should provide a workspace with sufficient light while still being free of distracting glare and shadows. An important relationship exists between ambient and task lighting. If the level of luminosity differs too much between task lighting and ambient light, it can be straining to the eyes. Accent lighting is used mostly to create visual interest or to emphasize specific features of the room. In either case, it should not be excessively bright, as to be distracting or to contribute to light pollution. The second area of interest in conservation of electricity is the actual fixtures and appliances used. New developments are constantly being made in the areas of more efficient lighting fixtures and appliances. Energy Star has created a rating system that qualifies appliances to certain level of energy efficiency. Similarly, the type of lamp used can consume sufficiently less energy and can give off a fuller spectrum of color. Compact 7

8 florescent lamps are 75% more energy efficient than are standard incandescent bulbs, and last 6 10 times longer. Advancements are being made in the area of use of LEDs that use fractions of the energy to provide more light. The final area and perhaps the most accessible to everyone are the user practices concerning electricity consumption. Simply turning off lights when a room is vacant, or unplugging the computer when not in use (computers still draw power even when fully shut down) has a dramatic effect on the amount of energy a building consumes. There are devices that can aid in this effort. Occupancy sensors can detect when the room is vacant and shut down power until again occupied, and timers that shut off lights after a certain amount of time so that they don t remain on for long periods of time when unnecessary. By putting into practice these strategies, residential homes can see as much as a 30% decrease in energy costs, and commercial buildings have the potential for even more dramatic repercussions. As students in the school of architecture, we have the highest responsibility to demonstrate understanding about the importance of conservation. We cannot simply talk about what must be done for the future of our built environment, but we must also use the aforementioned systems to better our designs both aesthetically and in efficiency. As we apply these principles, not only can we directly benefit from the energy savings in the buildings we occupy, but we can enhance the quality of the environment for future generations. 8