Introduction

Research Questions

This research proposal is aimed at identifying the HVAC systems used, their shortcomings in green construction and the methodology or design strategy that can be used to ensure that these systems are efficient. Moreover, the research is aimed at identifying the various power systems that may be used in sustainable construction.
Based on the above statement, there are several sub questions that may be used to answer the main research question. The research sub-questions are as follows: 1) what are the most common HVAC and power systems that are used in developing countries. 2) What are the effects of these systems on the general building industry and the environment? 3) Are there any other alternatives to these systems that can be easily implemented in the building sector with minimal or lesser effect?
The two systems that are involved in this research are pivotal in the building industry. Sustainable building construction has been centered on the energy efficiency of the building which may fall under the power and energy conservation and/or use. The power system is used to supply the energy as well as the lighting requirements of the building while the HVAC system is used to ensure that the internal environment is pleasant and comfortable to the occupants. However, the use of an inefficient HVAC and power systems may lead to environmental pollution and/or energy waste.
All that stated, the research can be used alongside other research to identify and ensure that there is proper building design and systems use.Moreoever, the research may be used to identify the best possible power source for use in green buildings. In a nutshell, it is a research that may serve as a platform from which the wheel of sustainable development in terms of power and HVAC system design may be based.
 

The choice of HVAC and power systems in sustainable building construction

Green buildings have been regarded as the buildings of the future. There have been continuous developments in the building sector so as to reduce the energy consumption and emissions from buildings. On this note, the building sector is one of the major consumers of energy which in turn means that there is a major carbon footprint emanating from this sector. Nevertheless, there is not a single definition of what a green building is.Most professionals have come to the conclusion that green buildings are those which are efficient in terms of resource use, efficient on energy use and can easily adapted for various functionality (Kibert, 2016). Moreover, these buildings can be easily operated and are very important for the long term productivity and safety of the occupants. Therefore, such a building is usually dependent on various architectural as well as engineering aspects.
Rating systems have been used to establish sustainability in building construction but each rating system focuses on a set of building attributes (Fowler, 2007). Some may focus on the drainage, others focus on power consumption, others on ventilation and so on. Therefore, prior to building construction, the proprietor has to determine the type of systems to be used if the building is to achieve the state and country rating requirements. All this will be as per the specifications of the building services engineer, the architects and other specialized construction teams.
Nevertheless, building services play a major role in sustainable development. The heating, ventilation and air conditioning system is of major significance in sustainable construction. However, the choice of the type of appliances used to achieve the desired levels of internal comfort without emission poses a major challenge to these specialized workforce. Moreover, the choice of the power source is also something of concern to the workforce. As a matter of fact, sustainable construction will be achieved by using the renewable energy sources as opposed to the non-renewable energy sources such as fossil fuels (Dobson, 2007). The current use of fossil fuels across the globe and particularly in developing countries supersedes the rate of regeneration and as such, now, more than ever, there is need to use the renewable energy sources such as solar, wind and biofuels among others. Furthermore, the greenhouse gases that are released during the combustion of fossil fuels have led to a change in the world climates which is of adverse effect to the planet.
On the matter of renewable energy sources, there are a number of choices placed at the front door of the building sector. An energy source used in one area may not work efficiently in other areas and this is something of future consideration. These power sources are associated with different disadvantages as well as advantages. However the bottom line is to ensure that the system selected works best with very minimal effect.
It has been established that HVAC systems may lead to environmental destruction because of improper selection. Fossil fuel depletion may be caused by unnecessary energy use while the appearance as well as the noise from these systems may result to pollution. Therefore the role of the HVAC systems in sustainable and green building construction cannot be overlooked. They are fundamental in ensuring that such buildings perform highly during operations. As such, it is important for building developers to consider the type of systems that may be used in sustainable construction. The choice of the HVAC systems used and the type of power generation method used should therefore be at the forefront of sustainable building development. Power system selection may be difficult considering the advantages and disadvantages of the various systems available. On the other hand, HVAC systems are continually developing with new and emerging trends but the design method used should also be sustainable.
 

Literature Review:
HVAC system

The System is used to create a conducive environment for the occcupans.Nevertheless, it requires an integration of the various building aspects in order to attain full efficiency. The system is composed of the equipment and services used for heating, air conditioning and ventilation. Though they may be separate entities, full comfort in an enclosed environment can only be achieved when they are properly coordinated (De Souza, 2013). Moreover, it has been established that professionals that major in HVAC as well as other professionals in the building sector should understand the techniques and strategies used in green building design.

Heating

Heating in a building is mainly achieved through the use of a furnace or a boiler system. Considering that the heated air and/or fluid travels throughout the building structure through a system of pipes and ducts, it is really hard to maintain the temperature at the desired level. All this emanates from the heat losses that are encountered through convection and radiation (Hui, 2014). An increase in the heat losses means that there is an increased fuel requirement. An increase in the amount of fuel used may mean an increase in the emissions and moreover, the system design may not be sustainable.
One of the approaches used to ensure that the heat is maintained at the right temperature is by installation of duct heaters (Harris & McCaffer, 2013).These are heaters that convert electrical energy to heat energy and as such, maintain the temperature of any fluid or air that passes over them. Though this may be an increase in the investments made, it is a more sustainable approach in the long run. As a matter of fact, there are changes in duct heater structure that ensure that there is continuous monitoring of the temperature of the fluid or gas. A reduction in the temperature will automatically lead to an increase in the boiler output and as such, maintain of the temperature.
As with the sustainable design of the building, the architects and the engineers may ensure that the heating needs of the building are kept at a minimal. One such approach is a design of the building fabric to ensure that the internal temperatures can be maintained at about 21 degrees Celsius (Kubba, 2016).This is the temperature required for the desired human comfort levels to be achieved. The building fabric is a major player in heat losses and gains and as per the location and external as well as internal temperatures, the choice of materials should be based on the U-value (Harris & McCaffer, 2013).Secondly,a minimization of the simultaneous use of both systems, that is, those used for heating and cooling. Not only does this approach maintain the internal temperature, it also reduces the mount of power and heat used. Nonetheless, this strategy depends on the thermal mass of the structure.
Minimizing the opening and closing of windows reduces the heating and cooling requirements of the building. However, this is dependent on the type of building occupancy with buildings that most of the times remain unoccupied requiring temperature that may be just above the freezing temperature. Buildings that remain occupied most of the time such as residential may require higher temperatures and this may be maintained by decreasing the opening and closing of windows. This will ensure that there is minimal heating requirements.
Generators are used in heat generation but may work below the optimal design. As such, optimization should be done to ensure that these generators are efficient and meet the heating needs of the building. The centralized and individual system are used in this scenario (De Souza, 2013). The centralized system is whereby heat is generated at a strategic point in the building structure and supplied through the use of a pipe system. On the other hand, generators may be used to heat specific regions of the building structure so that to achieve very high efficiency levels. As such, the separate system usually has an efficiency of more than 99% but may not be suitable for small projects because of the humongous investments that are required.

Air conditioning

Maintaining the humidity levels within a building structure is vital for the comfort of an individual. Humidity levels within the environment determine the perspiration which in turn determine the body temperatures. Therefore, maintaining humidity through humidification as well as dehumidification is vital from the view point of the building services engineer.
Moreover, cooling of this internal environment is also of importance when it comes to air conditioning. The temperature will depend on the heating and cooling mechanisms that have been put in place. This, in turn, means that the engineer will have to implement a proper system of heating, cooling, humidification and dehumidification.
Considering that this is an important aspect of the comfort level accorded to the occupants, there are three systems that may be used. The system used may either fall in the category of split, centralized or mechanical. Mechanical systems are the most common for large buildings. However, the use of air handling units has continually gained momentum because of the ease with which they can maintain the internal temperatures and humidity. The system works by ensuring that there is continuous extraction as well as supply of the required air into the internal environment.
 
 
 

Ventilation

Ventilation is required to either remove odors, maintain internal temperatures or to remove moisture. As such, it forms an integral part of HVAC design. These are all aspects that consider periods when the internal environment is occupied. Nevertheless, ventilation can either be forced or natural. Natural ventilation is that which is done through the use of natural forces such as wind and temperature. The use of natural ventilation considers the driving forces from the external environment and as such, is cheap. However, the movement of air into and outside the building depends on the windows, doors and any other openings which are expenses when it comes to design. However, this is the most preferred method of ventilation.
Forced ventilation refers to the use of mechanical means such as fans in order to control the movement of air inside and outside the building. Though the method may be expensive than natural ventilation, there are numerous factors that may necessitate its use. To begin with, if the external air is not conducive, such as in streets and roadsides, the use of natural ventilation would not be recommended. Noise and security factors may also require forced ventilation. In this, if the external security and noise is not conducive, closing and opening of windows may be a disaster. Moreover, buildings which are situated in regions where the wind cannot maintain proper air quality, the use of forced ventilation may be the most preferred.
Nonetheless, the use of  a mixture of natural as well as forced ventilation may be the most suitable in many instances. In this case, the mechanical as well as the natural forces are used to maintain the internal air. As opposed to the mixed, assisted is whereby air is drawn into the building naturally but extraction is done through the mechanical system.
 

Power source

The power requirements of a building are controlled by the lighting required as well as the energy requirements. However, burning of fossil fuels is the most common energy and power production method. Nonetheless, it is important to understand that lighting is a major element when it comes to billing. The electricity can also be used to produce energy in boilers as well in the duct heaters. Therefore, identifying design strategies that reduce the consumption of electricity is a major component of sustainable development.
The lighting requirements, besides using other forms of power generation, may be reduced by daylight savings. Daylight savings is the use of natural light during the daytime. The use of this light through glass walls and roofs, use of bigger windows among others will reduce the electricity consumption which means a reduction in the carbon footprint.
Moreover, there are various alternative sources of power that may be used with no adverse effect on the environment. As opposed to fossil fuels, these sources are renewable and are pollution free. Some of these sources include solar, wave, biofuels and wind energy among others. Proper design and analysis is however required prior to the implementation of any of these renewable systems.
Wind energy is still under study and has been undeveloped over the past years due to techno economic shortcomings (Dobson, 2007). However, the source is attractive because it is free, readily available and non-pollutant. On the other hand, it may prove unreliable in other instances because of the unpredictability of wind energy. A platform has been developed to ensure that power is generated whenever a certain speed is attained and more to this, power can be generated at a constant frequency with varying wind speeds.
Solar energy, like wind is free, readily available and does not cause pollution. However, it is highly affected by various factors such as weather and building location. Nevertheless, it has been established that the only challenge is the collection of solar energy and storing it for electricity conversion. According to the location and the energy requirements of the building, the teams may select the solar pond method or the concentrators’ method of solar collection.
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Research Design

Considering the development in the building industry and the continuous refurbishment of buildings, the use of case studies will be one of the methods used to garner knowledge. Case studies of buildings which have developed HVAC systems as well as those that have ventured into the use of renewable energy is the major issue in this research. The energy efficiency that is observed in each HVAC system can be measured through the power consumption, the comfort levels and the carbon footprint (Yudelson, 2008).
The use of the rating system, as described before, is vital in the developing world. Rating systems focus on different building aspects and as such, the use of a single rating system across buildings which have different HVAC systems design as well as power sources can be used in the research (Azhar, Charlton, Olsen, & Ahmad, 2011). Some of the common rating systems include LEED and BREEAM.Nevertheless, it may also be necessary to use two or more rating system to identify the difference in energy efficiency of the different designs. These rating tools are defined as the methodologies that are used to identify the sustainability of a building and its comparison with other buildings in terms of energy efficiency, waste minimization etc. (The leadership in Energy and environmental design, 2007). Nevertheless, the system used should be centered on the energy consumption of a building as well as its energy efficiency.
Data can be collected primarily from the field through interviews and questionnaires. These are important strategies that can be used to obtain first hand data on the research questions. However, the field work may work in synchrony with the rating system used. Identifying the suitable rating system will provide a platform for the selection of buildings for the research. The construction managers, building services engineers, specialist engineers among others will need to be identified and the proper interview questions formulated. Some of the questions will include:1) What is the energy consumption of the identified building 2) What measures have be done to improve the energy efficiency of the building 3) What HVAC systems have been implemented 4) The power source used and any renewable alternative, and  5) the view point on the sustainability of the building.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Conclusion

The building structure as well as the power use is vital in determining sustainability. As such, a focus on the power consumption of a building and use of renewable resources is a major stepping stone in building design. Moreover, a focus on the HVAC systems that have been employed and the necessary measures that can be used to improve them also justifies research.
Nevertheless, the building industry should focus on the use of renewable power sources in order to reduce the depletion of fossil fuels. Moreover, the use of renewable energy sources reduces the carbon footprint of the building industry. On the other hand, use of proper design strategies on the HVAC systems will lower the energy requirements of the building.
 
 
 
 
 
 
 
 
 
 
 

 
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