In today’s building protocols, green engineering is a vital incorporation for civil engineers. Each time there is a new skyscraper on the street or the neighborhood, there is a high probability that it has incorporated some, if not all the green concepts in its design. With the advancement in technology, it has become natural for buildings to be green and modern in an innovative way. Green engineered building is efficient and apart from offering value to its owners and tenants, it benefits the environment. Some of the aspects that constitute a green building include rooftop gardens, solar energy, and wastewater reuse. Such can seem small in the initial stages but are of great significance in the long run. This paper explores in detail some of the green engineering concepts indicating that these concepts ensure sustainable development especially in the building industry.
To start with, a green-engineered building should be planned on an effective site and all necessary management methods ought to be applied in order to reduce its impact on environmental natural resources and minimize energy utilization (Anastas & Zimmerman, 2003). These planning methods include sitting design in areas far from sensitive resources, reducing disturbance around development and controlling storm water and erosion. A green building is one whose energy utilization can be optimized by proper building orientation (Novotny, Ahern & Brown, 2010). The urban areas have been realized to have more than 2-5 degree Celsius compared to the upcountry part of the same region. This is due to an effect called urban heat island effect. Green engineering is one concept that is fighting this effect through the following ways:
1. Walls: The walls of green buildings are painted with paints that are solar reflective.
2. Roofs: Green roofs are used where grasses, flowers and other light vegetations are planted on the roof of the buildings. Just like any plantation on the ground, it shades the surface and maintains it cool. Green roofs are also significant in growing local products in the city as well as reducing storm water runoff. Reflective painting can be used in coating asbestos cement roofing sheets as well as galvanized zinc sheets in order to reduce the temperature by more than 10%, thus offering a cooling environment to its dwellers (Anastas & Zimmerman, 2003).
3. Rain gardens: Unlike man-made filters, rain gardens are natural filters that are developed to seize certain depths of rainwater. Thereafter, the rainwater filters through dirt to get rid of hydrocarbon from parking lots. The hydrocarbons are removed in a procedure developed to copy the way nature normally filters water. By use of the right soils and plants the soil and plant roots captures the hydrocarbons and also reduce greatly the nitrogen and phosphorus present in storm water. When properly developed, rain gardens are capable of reducing total suspended solids by 95% and 75% of nitrogen and phosphorus (Novotny, et al., 2010).
4. Solar system: Solar panel is a fundamental component of a green building. It converts sunlight energy to electricity that contributes directly to the power grid that among other benefits reduces the user’s electricity bill, serve the user when the national grid has developed technical hitches and is environmentally friendly.
5. Bamboo flooring: It offers wood flooring that is durable yet from a quick renewable source, the bamboo tree. The use of rapidly renewable resources reduces waste of forests.
6. Whole house fan: Green construction is incorporating a fan that naturally cools the building. The whole house fan is a fan installed on the ceiling of a house that extracts hot air from the living parts of the house and into the attic (Anastas & Zimmerman, 2003). Trough the attic vents, the hot air is forced out and the fresh and cool outside air is forced inside due to the reduced pressure through open windows and doors.
The whole house fan controls significantly temperature in a building yet it is much less costly to run compared to the electricity-powered air conditioners. In this concept, Boyle’s Gas Law which states that the volume of a given mass of gas is inversely proportional to its pressure if the temperature remains constant is applied as p1V1=p2V2 where p is the pressure, V the volume of the gas (Anastas & Zimmerman, 2003).
7. Radiant barrier: A typical green-engineered building should consist of a radiant barrier. This is a material incorporated in the building in order to control summer heat gain and winter heat loss, thus reducing the need for energy. It reduces air conditioning cooling loads during summer and heating needs come winter season. It is composed of thin sheet, mostly aluminum used on either one or both sides of several substrate materials (Novotny, et al., 2010). The mathematical formula for this energy transfer is:
Q = mcpdt
Q = quantity of energy transferred (kJ, Btu)
m = mass of substance (kg, lb)
cp = specific heat of the substance (kJ/kgoC, kJ/kgoK, Btu/lb oF)
dt = temperature difference (rise or fall) in the substance (oC, K, oF)
In conclusion, Green engineering is a branch of civil engineering referring to construction done at the right location, with proper design in terms of temperature regulation, water and electricity supply, and eco friendly materials. A green building should provide its dwellers with healthy and comfortable surroundings at all climates. It should maintain cool temperatures in summer, warm temperatures in winter and their inside should be totally protected against rain. A green building should also offer pollution free air as well as light through doors, windows, and ventilators using no artificial methods. Moreover, this building ought to have solar, wind power, electrical and mechanical devices. Besides, it should supply portable water with proper drainage along with sewerage and rainwater harvesting system. It should also be fitted with safety devices. In order to offer natural greenery, a green building can be besieged with trees, grass, and other natural plantation.