Electrical Lighting System for Dwelling - Report Example

Introduction A dwelling can become energy efficient in two possible approaches. Since ancient times, buildings aredeveloped from local materials and made in a special manner to adapt to the local climate. Their orientation allows the dwellings during winter to benefit from the sun while attempting to exclude overheating during summer. Among the key areas of concern in designing such adaptations, include using fabrics and ensuring that internal space and its arrangement gave room to cool air circulation during summer and warm air during winter periods. Such designs allow a dwelling to have natural lighting and ventilation and radiant heat source. This method, of energy efficient buildings, no doubt, was a plus in the health of the homeowners. Things have changed though, and codes and regulations in the modern society tend to deny the natural air circulation into and out of the rooms. They propose developing dwelling houses have tight seals with high insulations to bar internal and external environments adapt accordingly. Employing this idea means house receive heat, air and lighting from the conventional ways different from the natural ways. It is common knowledge then that the higher the insulation levels the more ventilation needed more lighting and balancing of air temperatures will hold the sway. World policies require that the amount of emissions from one particular dwelling that add up to the total emission of the world be reduced to a minimum in order to achieve 2020 targets of clean and lower carbon emissions that are today. For this reason then, when buildings are being designed for home use, efforts that are more concerted will be put in reducing energy consumption levels (Utley). When houses which people live in are airtight, it means more exposure times of persons to moisture that has contamination. Recent reports show that people spent about 22 hours of a day indoors out of the possible 24 hours. At this rate, ventilation, heating and lighting when designing a building is not a light effort, or else the entire universe is lost. Fig 1 energy balance for a dwelling Indoor air quality Risks associated with poor indoor air quality call for measures to ensure ventilation in building is up to standards. Tighter buildings tend to accumulate more toxic gases and chemical pollutants that pose great health problems. Ancient regulation allowed free air circulation, which was an easy way of avoiding contamination and eventual health problems. A case of tuberculosis spread arose in the late 19th century due to free air circulation. Being airborne the epidemic swept across Europe killing more than a million persons. Such potential respiratory risks have line, bait, and singer, all hooked to dwelling ventilation design and implementation (Fraser). Modern regulations on ventilating a room bases on this menace that averting such catastrophes need consideration. Ancient buildings like the late Victorian Scottish tenement house according to research had more of volumetric airflow in comparison to a modern building. The amount of air entering depends greatly on the size of the ventilation vent. A combination of inlet vents and outlets vents make up the ventilation system. Among the inlet vents are plane opening like windows, slots and grilles. Typical vents that serve as outlet are plane opening slot vents, grilles, duct shafts, open vertical spaces connected to outside, and roof outlets. Knowing the vents for a room, the heating requirement, and air quality then vent sizing takes center stage. A criterion used to find the sizes that determine capacity of air circulation is referred as vent sizing. Energy consumption and thermal requirement make vent sizing a design to consider. More ventilation means more energy consumption for heating purposes or used for cooling. Points to note when sizing a vent are that the standard for flow rates for an individual is 5-10 dm3/s per person while air exchange rates need to range from 5-10h-1. Fig 2 Ventilation rates for various systems In estimating the vent size, many functions can be employed to calculate the size required. Rule of thumb becomes the simplest method where one estimates airflow rate to be within the required standards, make an assumption of right velocity according to standards, and then deductively calculate area of the opening. Naturally velocity may range between 1-2 m/s since change in pressure = 1/2 p*v2*E. to calculate the area A = qv/v. Energy consumption rates need be low as well as achieving desired functionality. Accurate methods should be employed in this criterion. Other method to be considered are the simplified tools which takes into account dwelling topology, envelop overall permeability, surrounding terrain and nearby weather station data. This method effectively provides a cumulative frequency distribution of pressure differences. Another important and more accurate method is the loop equation method. Fig 4 Loop 1-2-3-4-5-6-7-8-9-1 Finally a zonal model can be applied which utilizes a software on the computer which is fed with necessary data like wind speeds, wind direction, outside temperature and will give an output of airflows carbon dioxide concentration and the amount of energy consumed. This is probably the most efficient method because one is able to accurately determine the amount of energy available and still regulate the vent size to achieve energy levels of interest (Fraser). Fig 5 room design to allow flow of air Electrical Lighting system The need for energy use to remain low in housing is a crucial agenda to pursue owing to reports from survey which show that energy use is no longer in decline. Dwellings consume 20% of household electricity through provision of lighting. A lot of the light is wasted within the room as internal heat gained by fabrics and other material found in the house. Survey shows that a large number of people prefer natural lighting of the houses to modern artificial electric lighting. Natural light provide up to 100,000lux of light to the eye while electricity provide only up to 60 lux. In comparison, this is nearly a ten thousandth the required light for our eyes. Increasing the artificial electric light to levels of the sun is very costly. In designing rooms that use a lot or receive a lot of natural light, it is always important to consider the direction of rising sun. This will ensure light from the sun is not blocked from illuminating the rooms. In eastern Africa, for example a building window design should be in the west east direction. Illumination will be to the max. Fig 6 Percentage of energy requirement for various electrical appliances including lighting Engineers are always engaged in methods of reducing energy consumption is residential building and maintaining of required quality light levels. Windows and glass windowpanes are among the most common methods employed by contractors to minimize on the amount of energy used for lighting purposes. When a building is able to admit the sun lighting into the inside of a building, then dwellers could use it during the day hence saving energy. The amount of light required for a particular room is much dependent on the area coverage occupied by the room and the size of window openings allowed for the room (MacKechnie). Others contributing factors include color of the fabric inside the house and color used for the finishing, curtains available in the house, time of the year, family night routines, and individual attitudes towards light. Fig 7 Large windows to allow enough lighting during the day Energy consumed by electrical appliances responsible for lighting varies from 5 watts to 1000 watts depending with application and personal preferences. Light bulbs that use tungsten filament are known to emit heat and consume a lot of energy. Using fluorescent lighting minimizes heating and energy consumption levels. Fig 8 energy saver leds The latest energy saver bulb, are rated as low as 5watts amount of power. They practically offer the same illumination levels at a cheaper cost. Use of mirror and or reflecting surfaces for lighting systems goes along way into reducing the rating of lighting equipment required for a home. Latest prism shaped reflectors have been incorporated into fluorescent tube lighting. They offer best solutions towards achieving desired lighting standards as well as reducing on energy consumption. Fig 9 energy saver bulbs Heating the houses In presenting this report on heating and energy efficiency use, it is important to start by definition of key terms considered in the review. KWh: kilowatt hour L/KWh: litre per kilowatt hour W/m2: watt per metre squared Mg/MJ: milligrams per megajoules g/kg: grams per kilogram Embodied energy: energy that a machine produces when in use. Other terms of importance are efficiency of conversion, heat transfer system, and heat capacity. The need for heating varies with weather conditions at a given moment. How much it affects the internal environment is quite dependent on the building design and materials used for construction. Smaller rooms tend to keep more heat than bigger room spaces. Brick or stone houses are warm compared to wooden houses during cold seasons. The necessity to keep warm pushes homeowners to search for alternative sources of heating their rooms. Heating of houses can be achieved through various methods. Among the most readily available and used methods are the open fire, burning of wood or coal, multi-fuel burner, enclosed wood burner, pellet burner, flue gas heater, gas fire central heating, electric resistance heating, electric under floor, night stores, heat pumps, ceiling heating, diesel heaters, and oil-fired central heating. Wood is the most readily available heat source. Energy consumption by wood is between 0.4 and 0.6m3 or 125-200kg per 100KWh energy delivered. Wood delivers heat at efficiency levels of up to 15% which is low hence not an efficient way to heat up rooms. Wood produces effective heat capacities of around 2Kw to living rooms or rooms of interest. Wood effectiveness of heat transfer is very poor achieving application in only single room heating (Utley). They offer heat risks because of their high carbon emission rates. Coal has almost the same energy levels and environmental effects similar to wood fuel. Ways or improving energy efficiency involves using multi-fuel burner for both wood and coal. This improves heat capacities to 19kW. Enclosed wood burner too has efficiencies of up to 755 while improving heat capacities to 24kW levels. Making pellets out of wood increases the surface are and improves efficiency accordingly. It consumes up to 26kg for energy deliveries up to 100kWh. It achieves very high efficiencies of 92%. They have heating capacities of 11kW. Fig 10 wood heat source Flue gas heater is another source of heat for a dwelling room. They use 13kg of gas to deliver 100kWh of energy. This method is easier to use but very costly to afford. With the help of a fan in the house, they can help heat up the other rooms within the same roof with faster heat-up rates. They deliver to a max of 10kW under convection and radiations. They are made into small and portable size shapes. Gas-fired reticulated source of heat is probably the most efficient with very high heat capacities of 30kW and 90% efficiency max values. Have low energy consumptions as low as 10kg for 100kWh energy deliveries. Consistent with other energy reduction is the study of ways and methods of reducing electricity heaters. 100kkWh is consumed for every 100kWh energy delivered. Electric heaters have almost 100% efficiency with heating capacities of 3kW max. It is easy and convenient to use. They are automatically controlled using thermostats or other technologies to achieve control of preset desired temperature levels. Fast heat rates contribute to electric heating advantages (Utley). They can be installed everywhere in the house and are portable. Fig 11 electric heater In the event of designing a more convenient room to achieve desired heat levels, consider location of the house, the climatic conditions of the place, available fuels for heating, and the materials to be used for constructing the house. In colder regions, smaller rooms tend to conserve internal environment and will reduce the need frequent heating of the room hence reducing much of energy loss. From natural principle on warm and cold air, these regions should not have very high wall buildings for reasons that they might get very cold. Areas that always experience long periods of sunny intervals have a different approach to how the sizes of the rooms are designed. The rooms can be made relatively larger and higher wall heights. This way much of the heat can be distributed throughout the room. In cases where such places become cold smaller rooms within the house can be utilized for warming up (Levy). The type of energy to be used for heating is upon the homeowner. The utmost room design will depend on the structural engineers within the area. Conclusion Risks associated with poor indoor air quality call for measures to ensure ventilation in building is up to standards. Knowing the vents for a room, the heating requirement, and air quality then vent sizing takes center stage. Energy consumption and thermal requirement make vent sizing a design to consider. More ventilation means more energy consumption for heating purposes or used for cooling. Windows and glass windowpanes are among the most common methods employed by contractors to minimize on the amount of energy used for lighting purposes. When a building is able to admit the sun lighting into the inside of a building, then dwellers could use it during the day hence saving energy. Smaller rooms tend to keep more heat than bigger room spaces. Brick or stone houses are warm compared to wooden houses during cold seasons. The necessity to keep warm pushes homeowners to search for alternative sources of heating their rooms. In colder regions, smaller rooms tend to conserve internal environment and will reduce the need frequent heating of the room hence reducing much of energy loss. From natural principle on warm and cold air, these regions should not have very high walls. References Fraser,   V.J. "Evaluation  of   rooms   with   negative  pressure   ventilation ." ventilation (1993): 623-628. Levy, Sidney M. Project Management in Construction. New York: McGraw-Hill Professional, 2011. MacKechnie, Nick. "The Architecture Journal." Architecture Journal Profile (2009): 1-9. Utley,   J.I.  &  Shorrock,   L. "Domestic   energy   fact   file." Building  Research   (2008): 414-450. Wiseman, Carter. I. M. Pei: A Profile in American Architecture. New York: Harry N. Abrams, 2001. Read More