Building design and construction considers many factors prior to the actual implementation. Therefore, it is important to consider the sustainability aspect prior to the actual implementation. The energy efficiency of the building is one of the most vital aspects considered in the design. With the change in technology and increasing costs of fuels, the lighting and power usage has to be considered in detail.
There are a number of energy rating systems used all over the world to determine the level of energy efficiency of a building and this proves to be vital in determining the building design and construction. Consideration has to be made on the heating and ventilation system used. As such, the system should make maximum use on the natural factors such as wind and heat. Maximizing the use of natural factors not only leads to a reduction in the cost of heating and cooling system, it also ensures that the comfort levels are as per the requirements of the occupants.
As with the building in consideration, there is need to change the current heating and ventilation system. Therefore, proper analysis will have to made on the current heating and ventilation system. Minimizing the use of heating and cooling system and increasing the use of natural forces will play a major role in the upgrade of the current system and to achieve the desired rating systems. The building is of residential purposes which means that the comfort levels that should be achieved are different from a building serving other purposes such as office or any other building type. The use of windows which improve the air circulation will be fundamental in improving the energy efficiency of the building. Furthermore, a reduction in the amount of energy distributions using heat from the oil sources will improve the energy rating systems of the building by reducing the amount of carbon emissions from the same. The use of solar power may be one of the methods used to achieve this but it may also be important to consider other renewable energy sources.
There is a continued emphasis for efficient and sustainable building design and construction. The building sector is one of the key sectors that may be used to reduce the carbon emissions which affect the world temperatures .Increased emissions have led to the change in global temperatures which have affected life on the planet earth. Therefore, it is imperative to consider the type of energy used by a building and its overall emissions on the planet.
An energy efficient building has been described as that which uses about half the energy that is used by the standard buildings. One of the descriptions of energy efficient buildings is based on the U- value (Gowri, 2004). A decreased U-value means that the building has good energy performance and generally uses lower energy. All this is based on the design of the windows, walls, doors among other building properties which improve the heat gain and losses of a building. Based on this, the use of these building properties means that the building can cool or heat itself using the natural forces such as wind and light thereby decreasing the need for use of the artificial means.
The fabric of the building is based on the use of the conventional materials such as concrete and steel but improper design can lead to the gain or loss of heat. As a matter of fact, the building fabric is responsible for the loss of heat to amounts above 75% and this should be something of consideration in the building design and construction (Kibert, 2016). Nevertheless, the fabric of the building is composed of the roof, walls, windows, doors and the floor. Therefore, improper design may mean that the heat requirements of a building will increase and this may mean an increase in the use of electrical power mainly for lighting and building heating.
Considering all the aforementioned, energy requirements of a building will depend on the insulation provided, the window and door design and a ventilation and heat recovery system used. Various designers have come to understand that building which use low energy may require heat levels of between 50 and 60 kWh/m2 (The leadership in Energy and environmental design, 2007).Therefore, the designer and craftsmen may have to invest in improving the thermal bridges of the building.
Nevertheless energy efficient buildings may be placed in four categories depending on the level of heat and energy consumption. A standard building is one which has been designed to use minimal energy in maintaining its efficiency levels. On the other hand, a type 1 building is one which consumes only half the energy required by standard buildings and this is only achieved by improving the ventilation levels and investment in heat and ventilation recovery systems. As such, it has been estimated that type 1 buildings are about 0-5% more expensive than the standard buildings (Lee, et al., 2011). The third type of building, type 2 or passive energy building, has been designed in such a way that it consumes only a quarter of the energy that is needed by the standard building. To some extent, the energy requirements of such a building may be less than a quarter of the energy requirements of the standard buildings. As such, the building has gained usage momentum in various parts of Europe where the summers and winters are subject to extreme cold and heat. Such a building depends on the energy generated within the building fabric and this enables the occupants to stay warm during the winters. However, the building does not depend on a separate ventilation and heat system but is based on the heat recovery method of building design. Nevertheless, the building is more expensive to construct and may be about 10% more expensive than the standard buildings. Buildings of this class have been designed for energy efficiency and have very low U-values because of the air tightness and insulation properties of the building fabric. Considering that there is considerable investment on the materials used in designing the building, there are no additional measures to improve the thermal efficiency and insulation of the building through additional HVAC systems. The expense compensates the need for these additional systems.
The fourth class of building is known as the zero energy building. Such buildings may be independent of the energy grid supply and have zero energy requirements. Moreover, these buildings do not emit carbon which is fundamental in efficient building design. Finally, the highest building level when considering energy efficiency is the plus energy buildings. In additional to the passive energy buildings, these buildings have additional measures to conserve and use energy. They may use systems of solar and wind energy in order to conserve and maintain the desired heat levels within the building. Moreover, considering that such a building may have excess energy during the summer, the management may sell the energy and as such, ensure that there is excess amounts within the national grid system. During the winter, the building may buy this energy back to maintain its energy efficiency levels. Nevertheless, these buildings are very expensive and can be more than 10% more expensive than the standard buildings (Kernan, 2007).
This is the general term used to describe the systems that are used in cooling and heating the building structure. Generally, the acronym stands for heating ventilation and air conditioning of the building. Not only do these systems maintain the indoor temperatures, they can also be used to maintain the outdoor environment through the supply of proper air temperatures and conditions. Supply of fresh outdoor air is done in order to dilute the internal environments and as such, maintain the health levels of the internal air. The internal air may be contaminated with various pollutants such as organic compounds and odor from the furnishing and the building fabric. As such, the system serves to ensure that there is a proper and comfortable environment year in year out.
Based on the definition of a HVAC system, there is need to design an integrated controller system that can coordinate the functioning of all these systems.However,each component of a HVAC system depends on the design and the various components used in achieving the desired building comfort levels.
To begin with, the heating system installed may be based on boiler or furnace design. These are the two common sources of building heating with the distribution of heat based on a labyrinth of pipes that distribute the fluid all over the building. The ductwork used needs to cover every part of the building structure and moreover, may be used to heat the water that is used for bathing and other purposes. Therefore, this requires connection to the water supply system.
The duct system is responsible for the distribution of warm air throughout the building structure but maintaining the air fluid or air at the desired heat levels requires a more specialized system of duct heaters. Duct heaters are an integral part of the heating system since they convert electricity to heat. As such, the warm air that passes over these heaters is maintained at a relatively warmer temperature through conduction and convention. Nevertheless, these heaters are used for various heating purposes which may be supplementary, space or primary purposes.
Advancement in the heating system has ensured that these duct heaters can monitor the temperature of the room and as such adjust the heat output of the boilers. Nevertheless, it has been established that designing a heating system should be done during building design and this should be done by the architects, heating engineers and the specialists who fall under the heating umbrella.
There are various actions that may be used in reducing the heating needs of a building. To begin with, the design team has to consider the amount of heat that may be lost through the building fabric. The heating and cooling systems that will be used in this instance should maintain the internal temperature to about 18-22 degrees Celsius so that the occupants can achieve the desired comfort levels (US Green Building Council, n.d.).Therefore, it is imperative for the system employed to either add or remove the exact amount of heat required within the internal building environment. Designing the external walls in a manner that ensures heat dissipation and heat conduction are minimized may be one of the measures. Insulating the roof may be another method while using windows and doors may reduce the amount of heat dissipated through them. When the internal environment is warm, the design team may ensure that there is an incorporation of sun screening services which will reduce radiation. As with modification measures to be incorporated to an already designed building, a reduction in the amount of air entering the building from the external environment may be a proactive measure.
A reduction in the heating requirements of a building may be achieved through minimization in the use of both heating systems and the air conditioning ones. All this is dependent on the required comfort levels and the type of structure. The comfort levels in this will be maintained through the thermal mass (Lee, et al., 2011). Only using the heating systems as required will also save on the heating and cooling requirements of the building. Regardless of the building structure, the internal temperatures should be maintained at around 20 degrees Celsius (Kernan, 2007). Moreover, there should be a limit on the opening as well as the closing of windows as per the required heating levels. As with buildings that remain partially unoccupied such as offices, the temperatures should be maintained just a level above freezing point.
Optimization of the heat that is produced by generators is another important consideration in building design that improves the heat efficiency. In this, there are two systems that can be used in heating the building: the individual as well as the centralized systems. The first scenario is where heating is done to specific areas of the building through the use of radiators. However, when it comes to economics, this system is not economical because of the expenses although the efficiency is 100% (The Constructor, n.d.).As with the centralized heating system, the energy that is obtained from the generator is supplied through the duct system to the various parts of the building. Other aspects of heat efficient buildings include the use of heating pumps, the use of solar for heating optimization of the circuits that are used for heating and the system used in controlling the heating,
Ventilation in a building structure may either be natural or forced. Natural ventilation depends on the natural forces such as wind while forced ventilation requires the use of mechanical means such as a fan etc. Nevertheless, there are three purposes of ventilation when it comes to proper systems design: the moderation of temperatures in the internal environment, a reduction in the amount of moisture as well as odors which accumulate in the internal environment during periods of occupation and enhancing the circulation of air. Therefore, ventilation improves the levels of comfort within the internal building environment.
Considering the two types of ventilation that are stated, the most preferred is natural but in other instances, building design will have to incorporate forced ventilation. One of the factors that may advocate for the use of forced ventilation is the building location. In this, some buildings are too deep within the perimeter to allow natural ventilation to manage the internal environment. Secondly, buildings located in areas where the air quality is not satisfactory, such as in a factory or a road, may call for forced ventilation. Thirdly, noise may prevent the continuous openings of windows. Other buildings may be located in areas where wind cannot satisfactorily maintain the required ventilation levels. Other factors that may require this system include partitions which prevent the flow of air, draughts which may be adjacent to openings and privacy or security requirements.
Other types of ventilation include assisted, mixed mode and trickle. In mixed mode, there is the use of both natural as well as mechanical ventilation systems while assisted is where there is continuous movement of fresh air into the building through windows while extraction of the used up air is achieved through the use of a fan system.Finally,tricke ventilation is done in sealed buildings of the modern world.
In determining the ventilation required, the air changes is the determining factor. However, this is usually determined by the number of occupants and the size of the space. Therefore, air changes is calculated as liters per hour or the amount of air changed over a specified duration of time.
It is based on the control of the humidity of the internal environment. Therefore, the two terms that are used with air conditioning are humidification and dehumidification. Nevertheless, the control of the building humidity is important for comfort, condensation as well as other special environments.
However, air conditioning is described on both the cooling as well as control of the humidity. Dehumidification is an important aspect of air conditioning because it determines the amount of heat that can be lost through the skin. The loss of heat from the skin is determined by the amount of perspiration which is an important part of thermal comfort within the internal environment. Nevertheless, the levels of comfort that can be accorded to individuals will depend on the air temperature as well as the amount of humidity.
The definition of air conditioning is furthermore based on the ability of a system to regulate humidity, the quality and the temperature of the air within the internal environment. To achieve this, there should be a complex system of air dehumidification, humidification, heating and cooling.
Systems that are used for air conditioning can either be mechanical, centralized or split. However, the most common application of mechanical ventilation is through the air handling units. Air handling units are a complex set of ductwork and equipment to supply and extract the air that is within the internal and external building spaces..
It is important in building services design since it focuses on the ability of individuals to recognize the environment. Nevertheless, lighting may come either in artificial or natural form. Artificial lighting is provided by a light source such as a bulb while natural lighting is primarily provided by the sun.
Natural lighting is also known as daylighting and is part of the insolation provided by the sun but can be seen. It is useful in enhancing the comfort levels within the built environment since it determines the body clock as well as the level of tranquility. Enhancing natural lighting can be done in various ways such as increasing the size of the windows and doors, use of roof lighting, the change of walling into glass and so on.
Artificial lighting is provided to buildings in case the natural lighting is not available. Therefore, it is used during the night time to enhance the visibility of the built environment. Nevertheless, this type of lighting requires a light source which may be a bulb or any other electrical mean of providing light.
Of the two types of lighting systems, natural lighting is the most preferred because of economics and availability during the daytime. The use of this system enables cost savings on light energy use which is a major energy consumer in the building sector. Nevertheless, proper lighting improves the appearance of the environment and has health effects on the occupants.
Terms used to commonly describe light are illuminance and luminous flux. Illuminance refers to the degree of light on a surface and the units for measuring are lux.On the other hand, luminous flux is the degree or level of light that is received on a surface or produced by a light source.
Considering that there is continuous development in the building sector and an energy source is a necessity, a step forward may be on the use of renewable energy sources. The major advantage of these renewable energy sources is the fact that they are environmentally friendly, economical and cleaner. The most common means of energy and power generation involve the use of fossil fuels and this results into carbon emissions. The most common renewable energy sources include solar, wind, waves, and biofuels among others.
The major drawback in using wind for power generation is a shortage of technoeconomic study. This method has been studied since 1940 but there is still more that need to be solved and discusses. However, the method still relies on solar energy considering that it is solar energy that causes heating of the earth which results in wind generation.
The major advantage of wind energy is the fact that it is unlimited and does not exert an extra heat requirement on the planet. However, the source is unreliable considering the unsteady nature of wind. Therefore, the method should be used alongside other energy generation methods for proper power production. There are three types of wind power generation and these are small, medium and large.
According to research, the earth’s surface receives approximately 600 W/m2 of solar energy (Kothari & Nagrath, 2009). However, the value is different across different parts of the globe. Areas around the tropics receive high levels of insolation while the temperate areas receive a smaller value of solar energy.
Major advantages of solar energy include the pollutant and cost free nature, and the non exhaustability.However, like wind power, one of its major drawbacks is the fact that it is unreliable. Clouds and the nature of the sky determine the amount of solar density received per unit area and this is something that can vary every day. Nevertheless, methods for harnessing and storing this solar energy have continually been studied and it is a matter of time before a proper method is established.
There are two technologies currently employed for harnessing and storing solar energy: the solar ponds and the solar energy collectors. The latter is a method whereby collectors are used to collect solar energy after the temperatures go above 700 degrees Celsius (Kothari & Nagrath, 2009).Concentration of the heat energy enables the system to operate a heat engine which results into heat and power generation. The only drawback of such a system is the investment required to construct collectors and concentrators. As such, research is still ongoing on the best strategy to develop the technology.
As with the power generated from solar ponds, the main technology employed is the use of engines which can function at low temperatures. The heat engine is connected to a generator which can generate energy to feed the national grid. Moreover, the power generated may mean a reduction in the prices of power and energy.
The change in technology and requirements of a more sustainable approach to building development and renovation have advocated for proper building design. As such, it is imperative that housing design considers the HVAC system, lightning and the use of renewable energy. All these are factors that ensure that the building is comfortable and suitable for habitation.
There is a difference in the requirements of an office building, a residential development and a commercial building among others. Therefore, one of the proactive approaches to proper building design is to determine the type of building and its use. Employing the specialized group of engineers such as lightning experts, heating experts and other specialist groups will require humongous investment but the returns from such an investment will be observed over some duration of time. The building may be designed and redeveloped into any of the classes of energy efficient buildings and as per the money allocated for the design, it may be class 1, class 2, class 3, class 4 or class 5 building.
Class 1 buildings are energy efficient but are incomparable to class 5 buildings. However, the state requirements and the environmental conditions will also determine the type of building to be designed and redesigned. All the energy efficient systems will need to be incorporated into the design if the building is to attain the rating system required by the state and the governing body. That stated, there are different rating systems that can be used in determining the energy efficiency of building. Some examples of rating systems are LEED and BREEAM. Nevertheless, proper research and design considerations are very crucial in building design.
The current situation is that of a residential building. As such, some of the important design considerations are daylight savings, air conditioning, ventilation, lighting and saving on the cost of the power used. Buildings of residential stature are occupied throughout the day and ventilation stands above the other requirements.
The existing building has 6 rooms which means that the lighting requirements are also paramount to the redesign. However, this will be determined by the weather and the availability of sunshine in the locality. Daylight savings are crucial when it comes to saving on the bills emanating from lighting requirements.
As with the location, the building is located next to a footpath and a crossover. As discussed, the location of a building determines the type of systems to be installed. However, a footpath and crossover may determine the security requirements of the building which may in turn determine the window and door systems installed. Furthermore, this may also determine the noise that will be heard inside the building complex.
The walling system is also fundamental in the design considerations. As such, one of the factors to consider is the number of stories available. In this sense, the building has no floors and the only design consideration is the ground floor unit. Heat losses and gains are determined by the ambient temperature as well as the U-value of the materials used in the design of the floors.
Considering the building layout and design, one of the improvements to be made regards the roofing element. Roofing determines the internal atmosphere as well as the ventilation requirements to be made. The roof pitches at an angle of 22.5 degrees which may determine the air circulation. Nevertheless, the roof design may also be suitable for the particular location. Other roof design may be incorporated into the building structure to ensure that there is proper air circulation. Another aspect to be considered in the roof design is the need for daylight savings. The use of glasses in some portions of the roof structure may go a long way in ensuring that there is sufficient light penetrating into the internal environment. Light sufficiency is one of the methods that may lead to a reduction in the bills required for lighting.
Change in the window structure is also something of concern. Considering the size of given windows, an increase in size would be one of the viable solutions that would both increase the air circulation as well as increase the amount of light entering the building.However,another viable solution would be to increase the number of windows round the building structure. Increase in the number of windows will serve the same purpose as increasing the size of windows. As such, it will also ensure that there is an increase in the amount of light entering the building and sufficient distribution of fresh air. However, the design of windows will need to consider the security requirements of the region as well as the noise emanating from the outside environment. Survey of the number of people passing nearby, as such, will determine the window sizing as well as the location. When there is considerable heat from the external environment, glazing and window insulation may be of considerable importance. Window glazing reduces the amount of radiation entering the building structure while insulation prevents considerable loss of heat energy.
The wall units are an important part of the design consideration. It is from the wall units that heat is either gained or lost. As such, the materials used in constructing the walls have to be of considerable U-values.Moreoever, insulation may be provided in regions where the eternal environment is much cooler than the internal one. The building has been designed using concrete elements which is an important part of the design. If other viable construction materials are available, the design team will have to conduct a survey regarding the same.
Low voltage halogen bulb selection
Master bedroom washroom
Family and dining
Electricity and gas use as per last year
Based on the sustainable design, electricity use minimization is one of the objectives of green development. Not only does an increase in electricity result into the accumulation of bills, it also increases the carbon footprint. On this note, the gas and electricity consumption of the building the last year is as follows:
|Electricity (kWh/mth)||Gas (MJ/mth)|
The total electricity consumed is (303x 5) + (401x 7) =2807kWh/year
Nevertheless, as per the 2011/12 year, electricity in Australia was charged at 25 cents per kWh (Hutchens, 2018)
Therefore, to determine the electricity bill we multiply 0.25×2807=$ 701.7 that year
On the other hand, the gas used the previous year is (2223x 5) + (7002x 7) = 49013MJ/year
According to Aurora energy, the gas is supplied at 3.9204 cents per MJ of gas and a daily standing charge of 52,80 cents (Aurora Energy, 2018).Therefore, the total amount of cash spent on gas is (0.039204x 4901)+(0.5280×365)=$2114
Therefore, the total amount of cash spent on heating and lighting is 2114.2+701.7= $2816
Based on the upgrade conducted, there are various benefits to the environment, society and the economy. To begin with, a change in the lighting with focus on daylight illumination will reduce the amount of money used in paying electric bills. Daylight illumination will depend majorly on solar light which means savings. Moreover, the use of natural ventilation will mean a reduction in the amount of money used in forced ventilation. Forced ventilation is conducted through the use of fans and other mechanical devices and a reduction in their use result to a reduction in the bills. However, using solar energy will mean the complete minimization of electricity supplied by the national grid. The energy generated by solar radiation is cheap, readily available and pollutant free.
As with the environmental advantages of the upgrade, the most notable is a reduction in the carbon footprint. The reduction in the use of national grid power for electrical, lighting, gas and ventilation purposes means a reduction in emissions pertaining fossil fuel energy generation. Moreover, there will be a reduction in the heat losses and gains from buildings. The use of natural ventilation in place of forced ventilation will also mean a reduction in the energy consumption of the building.
The social advantages of the upgrade means a reduction in noise pollution and a more tranquil environment. Machinery that generate heat and those used for ventilation produce noises which may have adverse effects on the society. Therefore, a reduction in the use of such machines improves the social welfare. Moreover, daylight lighting are important aspects of psychological development. In this, there is a reduction in eye strain and the creation of a more tranquil environment.
Sustainable building design forms an intricate part of building design. There is a continued need and emphasis on green buildings. These buildings utilize the least amount of energy for optimal performance. As with the building design, consideration has been made on the required levels of energy performance as well as type of building.
Improving the building energy efficiency through the use of solar power and renewable gas improves the energy efficiency. Furthermore, the use of natural ventilation also reduces the electricity and gas consumption. In essence there is a reduction in the long term costs of the building as demonstrated by the life cycle costing
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