Energy Performance of Curtain Wall

Energy Performance of Curtain Wall Introduction Building envelope is used to separate the conditioned and unconditioned environment, the material used in envelop will affect the indoor environment of the building. For a commercial building, the electricity consumption of HVAC system and lighting system is related to the features of the curtain wall system, such as U-value, shading coefficient and visible transmittance. The energy performance of each curtain wall system will be studied in this chapter and it can separate into three sections: 1) U-value and Energy Consumption of HVAC system, 2) Shading Coefficient and Energy Consumption of HVAC system and 3) Visible Transmittance and Energy Consumption of Lighting system. U-value and Energy Consumption of HVAC system According to Bougdah (2009), U-value, a thermal transmittance coefficient, is used to measure the insulation property of a building element. As thermal insulation of curtain wall may affect the energy consumption of the building, the relationship between U-Value and energy consumption of HVAC systems is studied in order to analyze the energy performance of various curtain wall system. Based on table 6.2.1, the relationship between U-value and energy consumption of HVAC systems can be shown. The U-value of curtain wall system is directly proportional to the annual energy consumption of HVAC system. With higher values of U-value, the energy performance of the curtain wall system becomes poorer and it requires more electricity as the heat can more easily transfer from outdoor to indoor. On the contrary, the lower in U-value, curtain wall system can perform better energy consumption in HVAC system. Table 6.2.1 U-value and Energy Performance of HVAC System of Targeted Curtain Wall Figure 6.2.1 Relationship between U-Value and Energy Consumption of HVAC System Figure 6.2.1 demonstrates the directly proportional relationship between U-value and energy consumption of HVAC system obviously. With the saw-tooth pattern of the line chart, there are some types of curtain wall system which have three layers of glazing require more energy than two layers one. It means that there are other factors, such as shading coefficient, which may also affect the energy performance of the HVAC system. The relationship between shading coefficient and annual energy consumption of HVAC system will be discussed in the next section. Shading Coefficient and Energy Consumption of HVAC system According to Ander (2014), the shading coefficient of glass is a measure to determine the solar heat gain through the glazing. Radiation is a method to transfer heat from the outdoor environment to the indoor environment. For commercial buildings with curtain wall system, shading coefficient becomes another major factor that affects the amount of heat transferred to the building. The external envelope of the building is glazing which has lower insulation for heat transmission through radiation. Since the shading coefficient will affect the energy consumption, the relationship of shading coefficient and energy consumption of HVAC system is studied. Based on the table 6.3.1 below, the shading coefficient of curtain wall is directly proportion to the energy consumption of HVAC system. It means that the amount of annual energy consumption of HVAC system becomes higher with a relatively high shading coefficient of curtain wall system. With the lower of the shading coefficient, the lower the energy consumption of HVAC system, less heat transfer from external environment to internal environment. The major factor affected the shading coefficient of curtain wall system is the type of glazing. In this study, clear glasses and tinted glasses are used in various types of curtain wall. Tinted glass is a common glazing that used to construct the curtain wall system and Pfrommer (1995) stated that the tinting can produce various colours, such as green, bronzer and tinted glass can absorb solar radiation and reduce those heat and light transmission. Tinted glass can perform a better energy saving performance compared with clear glass which do not contain any chemicals to absorb radiation. However, the price of curtain wall system with tinted glass is more expensive than clear glass. Besides, the number of layers of curtain wall system is another reason affected the shading coefficient of that curtain wall system. It is easy to understand that the radiation transmission becomes lower with a higher number of layers of curtain wall system. Therefore, triple glazed curtain wall with tinted glass has the lowest annual energy consumption while single glazed curtain wall with clear glass has the highest annual energy consumption. Table 6.3.1 Shading Coefficient and Energy Performance of HVAC System of Targeted Curtain Wall Figure 6.2.1 Relationship between shading coefficient and Energy Consumption of HVAC System From the figure 6.2.1 above, a straight proportional relationship between shading coefficient and annual energy consumption of HVAC system can be identified. Type I triple glazed curtain wall system with spectrally low-e tinted glass which has the lowest shading coefficient has the best performance in annual energy consumption of HVAC system. However, Type A single glazed curtain wall system with clear glass which has the highest shading coefficient has the poorest performance in annual energy consumption of HVAC system. Visible Transmittance and Energy Consumption of Lighting System Apart from the attractive appearance, a high portion of natural lighting is another characteristic of curtain wall system. Unlike other external wall construction, curtain wall systems are constructed by glazing elements and more daylighting can pass through to the indoor environment of the building. Efficient Windows Collaborative (2014) stated that visible transmittance is the amount of light in the visible portion of the light spectrum that passes through glasses and it will be influenced by the glazing type, the number of panels, and any glass coatings. Based on the table 6.4.1 and figure 6.4.1, lighting transmittance is inversely proportional to the annual energy consumption of the lighting system. With a higher value of lighting transmittance, the amount of annual energy consumption of lighting system becomes lower. It means that more visible light transmitted from the external environment to internal environment and the target building can save more energy in lighting system. However, more energy is used in lighting system in case the value of lighting transmittance is in a small value. In this study, two factors affect the lighting transmittance of curtain wall can be identified. The first reason is the number of layers. More layers can increase the thickness of curtain wall, thus less visible daylighting can pass through curtain wall. This is easy to understand that triple glazed curtain wall system blocks more lighting than single glazed curtain wall and double glazed curtain wall system. The second reason is the type of glazi ng. From table 6.4.1, clear glasses always have higher lighting transmittance than tinted glasses. As mentioned above, tinted glasses can reduce light transmission. Although it performs good energy saving in HVAC system, it consumes more energy in lighting system. Table 6.4.1 Visible Transmittance and Energy Performance of Lighting System of Targeted Curtain Wall Figure 6.4.1 Relationship between Visible Transmittance and Annual Energy Consumption of Lighting System From the above figure 6.4.1, the inversely proportional relationship between visible transmittance and annual energy consumption of lighting system is shown. Type I triple glazed curtain wall system with spectrally low-e tinted glass which has the lowest visible transmittance has the poorest performance in annual energy consumption of lighting system. Nevertheless, Type A single glazed curtain wall system with clear glass which has the highest visible transmittance has the best performance in annual energy consumption of lighting system. Overall Performance in Energy Performance After assessment, the performance of each curtain wall system can be assessed. Using the ranking as the score to calculate the performance of curtain wall, curtain wall system with a higher performance score means they perform better in energy consumption of Building A. The performance ranking is converted to score from 1 (the poorest performer) to 10 (the best performer). As around 70% of electricity is consumed by HVAC system normally, the over score is equal to â€Å"HVAC System Score x 70% + Lighting System Score x 30%†. Based on the following table, Type J obtains the highest score in this study, whereas type B obtain the lowest score in this study. Table 6.5.1 Score of Targeted Curtain Wall System Type A Curtain Wall System Type A curtain wall is constructed by single glazed with clear glass. As there is only one layer of glass, the U-value of curtain wall is the lowest. Clear glass used in Type A cannot absorb radiation but it can provide more visible lighting to Building A. From the above reason, Type A obtains the highest score in lighting system and the lowest score in HVAC system. Type B Curtain Wall System Single glazed with tinted glass curtain wall system is similar to Type A curtain wall system. Nevertheless, tinted glass is used in this curtain wall system. Type B curtain wall system has a relatively low shading coefficient and visible transmittance compared with Type A curtain wall system. Type C Curtain Wall System Type C curtain wall system is double glazed with low-e tinted glass. The low-e coating can minimize the amount of ultraviolet and infrared light that pass through glass. As there is air space between two glasses, the U-value of curtain wall is lower than curtain wall system with one layer. And less heat can be transferred from the external environment to the internal environment since tinted glasses can reduce the heat transmittance through radiation. Type D Curtain Wall System Type D curtain wall system is double glazed with low-e clear glass. Compared with Type C, it has better performance in annual energy consumption of lighting system as it has a higher value in visible transmittance. However, clear glass has a poor performance in thermal insulation in which the amount of heat transmitted through radiation is higher than Type C. Type E Curtain Wall System The emissivity level of Type E curtain wall system is lower than 0.1. With a spectrally low-e value, U-value and shading coefficient of the curtain wall system will be reduced and the energy consumption of HVAC system also can be reduced. However, the visible transmittance will be reduced because of the low-e coating. Type F Curtain Wall System Like Type E curtain wall system, it performs a better performance than Type D in saving energy of HVAC system because of spectrally low-e coating. On the contrary, the annual energy consumption of Type F curtain wall system in lighting system is higher than Type D which has the same number of layers as Type E curtain wall system Type G Curtain Wall System Type G curtain wall system is constructed by three layers of tinted glass and its U-value is higher than previous curtain wall systems. It has a better thermal insulation compared to one layer and two layers because of increasing in thickness and number of air space. It ranks no.3 in this assessment because of its low value of shading coefficient and U-value. Type H Curtain Wall System Triple glazed with low-e clear glass has same U-value as Type G. Nevertheless, the visible transmittance of Type H curtain wall system is higher than Type G since Type H curtain wall uses clear glasses which cannot absorb radiation. As mentioned before, the thermal insulation of clear glass is relatively lower than tinted glass used in Type G. Type I Curtain Wall System In this assessment, Type I has the highest score. The emissivity of Type I curtain wall system is lower than 0.1. The U-Value and shading coefficient of Type I are lower than Type G system and it has the best performance in annual energy consumption of HVAC system. Type J Curtain Wall System Triple glazed with spectrally low-e clear glass has a better performance than Type I in the energy consumption lighting system. However, more heat can be transferred to indoor as shading coefficient of clear glasses is higher than Type I. It still ranks no.2 in energy consumption because of three layer glass and spectrally low-e coating of curtain wall. In figure 6.5.1, U-value and shading coefficient are direct proportion to the annual energy consumption of HVAC system and it means that both of them may affect the energy consumption directly. For energy consumption of lighting system, visible transmittance can influence the curtain wall performance. However, an interesting results is identified. The influence of shading coefficient is more obvious compared to U-value. Using Type B and Type D curtain wall system as an example, although Type B and Type D have similar amounts of annual energy consumption in lighting system, the U-value of type B is much higher than type D. It shows that the shading coefficient of curtain wall system is in the first priority during making decision on the types of curtain wall system. Figure 6.5.1 Overall Performance of targeted building in HVAC System

Cutting Down Trees

Cutting down too many trees will result in nature being gone very soon. We will not be able to survive because we live on the oxygen that trees and plants breathe out. Because we need O2 and give off CO2, and because trees and plants breathe CO2 and give off O2, if one group is not there then the other will die. It is a bad thing if we keep cutting down trees in an unlimited way. In addition to the impact on the balance of gases (O2-CO2), trees and plants provide habitat for huge numbers of creatures. It is possible to kill off many whole species of animal by destroying their habitats. Losses like that (large-scale habitat destruction) are not easily reversed, and will drive large numbers of creatures into extinction. Taking away the homes of creatures, allowing them to completely die off, and then restoring the habitat won't bring them back. Trees should not be cut down because most of the paper used is not RECYCLED so therefore it is a waste of time from God to make and plant the tree! Well it has air and oxygen and if u are cutting the trees down u re hurting the enivorment and animals that live near trees or on trees like rabbits and all could die and the it causes flooding to the world and near the forest so all the animals can die. Also school is wasting mire paper by thinking they have enogh but they dont. Some people also do littering and people who do that i would like to remind them that when u are older and u litter and the police caches u then u can get arrested. Schools are all coverd in litter and it very important that u dont because u can still get in trouble even when u are younger. By the lack of litter that i have found in this street and i am very dissapointed please dont litter it is very important that u dont. Headteachers at school are doing a brilliant job by picking up the litter. Even if it is not ur litter please just pick it up. If u see someone chucking rubbish on the floor say to them dont do that it is not gd for the enviorment. One of the most significant impacts of cutting down trees is that they are a source of shelter to many animal species and they become homeless because of this and it becomes difficult for them to survive. As a result the entire food chain is affected. Cutting down trees means that we have lesser number of tree species left and this decreases the biodiversity. Plants release oxygen into the environment and lesser number of trees means that we will have lesser oxygen content in the atmosphere. Tree leaves also give off water molecules to the environment that become a part of the water cycle and come down as rain. Fewer trees means lesser rains. Trees refresh the air we breath so by chopping them down we will have a poorer air type No shelter for animals. No oxygen for humans.

Tooth Fairy Belief

There have been so many things I have believed in since I was a child but have discovered they were not true as I grew up. Knowing that these beliefs are untrue has helped me form my opinions about life. The greatest myth I have believed in was the Tooth Fairy. However, I am glad I found out it was not real because it taught me that in life you have to work for what you want. I can recall a memory I have of when my first tooth fell out. I was five years old when I started to lose my teeth. I was so afraid to pull out my falling teeth but my mom would tell me that it was not that painful and that if I pulled it out I would see the benefits. Then she began to tell me the story about the Tooth Fairy and how she would leave a dollar under my pillow in exchange for my teeth. Of course I listened to my mom, I did as she said and twisted my tooth until it was really loose and pulled it out. I was so excited to get money so I quickly put my tooth under my pillow and went to sleep anxious to receive money the next morning. To my surprise I found a dollar in quarters the following morning. This made me believe that indeed the tooth fairy was real. Every time I would lose a tooth I wouldn’t be scared to pull it out anymore. In fact, it became an addiction for me because I wanted all my teeth to fall out quickly so I could receive more money. My experience with the Tooth Fairy made me believe that everything in life was free. This belief actually shaped my ideas of the world. For instance, I thought that good things could happen with a little bit of effort. By believing in the Tooth Fairy I thought that anything was possible without having to work hard. My discovery about the Tooth Fairy being untrue changed my life in a positive way. As time progressed and I matured, I realized that it was not the Tooth Fairy that put money under my pillow but instead it was my mom. The way I found that the Tooth Fairy did not exist happened one night I lost my tooth. I was very curious to know who the Tooth Fairy was; therefore I acted as if I was asleep. Soon I saw my mom enter my room and since I slept with a night light I was able to see her face. I didn’t make it obvious that I saw her because I did not want to embarrass her. I waited until the next morning to tell her that I had found out the truth. When I told her about my discovery, she denied it instantly. She said I must have dreamt that I saw her. Later when she had no other excuse, she admitted it. I understood her because she said that the story makes this sort of tradition more exciting. When you believe in a fairy or other things such as Santa Clause, it makes things seem more magical. It is a thrill to be anxious the next morning and receive money or gifts. It wouldn’t be so fun to know your parents are the ones who do all of these things for you because you see them everyday and can ask them for what you want. It wasn’t a deception to discover this was all a lie. In fact, I was grateful to know that the Tooth Fairy did not exist because I learned that things in life have to be earned. Some of my thoughts and opinions towards life changed for good after realizing that the Tooth Fairy was a myth. First, I used to live in a world of fantasy when I was younger. I also used to believe that I could get anything I asked for in life and that I had to put little effort to get the things I desired. Now that I am grown up I realize that it is not easy to get a mansion by asking for it but rather working hard for it. The way that I came into these opinions is by comparing how my life used to be before when I believed in the Tooth Fairy to now that I know the truth. When I used to think the Tooth Fairy would leave me money in exchange for my teeth , I used to think that I could just get things the easy way. It is very different now because I realized that there is not a Tooth Fairy giving me money to pay for my college books and tuition. The world we live in is very complicated to survive in if you do not occupy yourself into something that will help you succeed. Money will not rain from the sky or be left magically under a pillow. This is why it is important to work to achieve our goals! I believe that the more you try or the greater effort you put, the greater are the chances that you will get what you most desire. Parents should not tell their children false stories because sometimes those stories can affect them in their lives. Some stories affect children’s mentality because children are vulnerable. For example, some children that believe in the Tooth Fairy can take extreme measures such as trying to pull ut others teeth just to obtain money. This can be very harmful to other children because a child might harm another kid to try and knock their teeth out just for the sake of earning some money. I am aware that some parents tell their children lies to make them act right. However, parents need to take in consideration that children are not going to think about behaving well but rather do the things that benefit them. If they can g et money under their pillow just for a tooth they will beat up any other kid just too simply get their teeth. It seems insane but it is true that children go way beyond to get what they want. Finally, discovering that the tooth fairy was not real changed the person I am today. If I hadn’t believed in the Tooth Fairy I may not have learned so many lessons in my life. The greatest lesson I have learned so far is that nothing in this world is free. Life puts us through many challenges that we need to overcome in order to achieve those things we want. No matter how hard you have to work for something it will pay off in the end!

The Snow Ski An Artefact - 1536 Words

The Snow ski an artefact in which today we take for granted. This essay will be focussed on comparing two eras, the medieval ages and today. These two time periods are selected to help depict the skis relevance towards material in culture. Material culture is best defined as objects which contribute towards our cultural and social wellbeing whether it’s a family emblem or a product consumed by the masses. It is artefacts from historical periods their designs and how they impact our lives. There will be a review on the functionality and the cultural importance of the ski and a reflection of concerns of consumerism and social wellbeing. Personal and contextual information will clarify the defining moment of the skis transition from its origin. This essay will not be a historical timeline, instead it will indicate how the snow ski, as an artefact, has been stripped from its original purpose of transportation, and transformed into one of the world’s most extreme and luxuri ous Sports. Extreme sport: a sport involving great danger, an activity which pushes the boundaries of human’s physicality (Oxford University Press, 2015). Today skiing is considered as one of the world’s most extreme sports as the skier exhausts their body, challenging the execution of turns at an average speed of 46.7kmh (Johnson, 2005). The latest technology and engineering in ski development, is focussed on improving the design for speed and control. We use the ski as an instrument of entertainment andShow MoreRelatedImproving Profitability By Applying Sustainable Strategies9898 Words   |  40 PagesNeedless to say, his grandmother was not pleased as the ceilings were painted and not inexpensive to repair. Skiing - On May 6 1903, 14 young men sat down at a table in the Cafe Royal and decided that Britain needed a Ski Club to promote and grow the sport of skiing. And so the Ski Club of Great Britain was born. In the 1800’s the main entrance was on Air Street – where the bar is now located, as popularity grew the main entrance moved to Regents Street where we are now. The Cafà © Royal was a centre