Acknowledgement I would like to express my special gratitude and thanks to supervisor Dr. Patrick X.W. Zou and guide MD Morshed Alam. Furthermore, I would like to thank Professor Yun Yang for guidance on report. Abstract The report discuss about use of Water -Energy Nexus concept on building. Basic need for water and energy is growing and not all of population are getting benefits of it. Currently world population is growing substantially and basic need for them is also growing rapidly. However, non-renewable sources are depleting and there is need for finding different alternatives. Statics suggest that, more than one third population of world will be living in water scare-region by 2025.To mitigate this problem we need to find best way to save water and energy for future generation. Construction industry is one of the biggest consumers of energy and water. By analysing their usage and developing new strategies we can save considerable amount of water and energy. The aim of report is to use Water-Energy approach to analysis water and energy use in building for sustainable development. This study not only provide inter-link to improve efficiency but also help to develop strategies which are beneficial for environment. Adapting to new technologies with higher efficiency can save owner's money on water bills and energy bills. Table of Contents Introduction 2 Review of Report 2 Problem Statement 2 Sub problems 2 Hypothesis 2 Delimitation of report 2 Assumption in report 3 Significance of the report 3 Literature Review 3 Present Scenario 3 Global scenario 3 Australia scenario 4 Analysis 4 Methodology 4 Heating and Cooling System (HVAC system) 4 Case study of HVAC system 4 Discussion on Result 5 Conclusion and future work 6 Reference 6 Table of figure Figure 1 (a) Chilled water buffer vessel (b)Insulated heating hot water pump and pipe work 5 Keywords - Water-Energy Nexus, HVAC system, National Australian Built Environment Rating System (NABERS) Introduction The world is undergoing serious changes due to activities of mankind. Environmental degradation due emission of Green House Gas and other such reason leads to severe environmental conditional. Various strategies are developed to overcome environmental hazards and to control activities that leads to degradation. Water Energy Nexus is relation between water and energy. How one entity has impact on other for example to distribute water to different place we require energy to pump water. Similarly, to generate electricity for hydro-electric power plant water is required. This nexus can help to develop strategies and technologies which will help save water and energy. Before this concept of water energy nexus research has their focus solely on water efficiency or either energy efficiency. In recent years' inter-link between water and energy are studied. This nexus helps to co-relate water and energy and to help improve efficiency of one entity in regards to other entity. Many other nexuses are derived from this nexus like Food-Energy and Water Nexus and Water-Energy and Carbon nexus. The report gives information regarding water energy nexus in building. Most research on nexus is based on large scale like for a particular country. There are reports which talk about water energy nexus for a city or for some building. Very few report talks about particular building. Analysing nexus in building in context of water energy nexus will open door to new opportunities in this field. Building industry can grow to new level and can achieve new standards of sustainable development. Report Criteria Report criteria are discussed bellow. Problem Statement Environment conditions are becoming worst as days are passing by, having severe impact on the livings at a global scale. Major steps are required to be taken for reducing environmental impact. Conserving water and energy by different mean can help to achieve this goal. Saving water on ground level as in building and day-today activity can lead to major conserving step. Sub problems Existing Building are using more water and energy because of inefficient system prevailing in old technologies. Due to use of more energy and water in building for daily activities has serious effect on environment. More consumption of this leads to high electric bills and water bills which ultimately results into poor cost benefit analysis for building. Hypothesis Water-energy nexus approach in building can provide basis for system that can be helpful in improve energy efficiency and water efficiency for sustainable development. Delimitation of report Embodied energy associated with system suggested are not consider in this report. Report will not address losses that occur during transmission of water and energy. Consumption rate for particular technologies are relied on general source, it may be varying according to situations. Assumption in report Report is based on specific weather condition and does not include seasonal change. Data analysis is based on Australian case study which may not be applicable on global scale. Significance of the report This report will help to develop understanding of relation between water and energy at building level. Application of nexus will help to improve energy and water efficiency which will help to reduce bills and will save money. It can be proved as one of the step towards sustainable development for improving environmental condition. Literature Review The existing technologies installed in building for various water and energy system are not efficient. This has environmental impact and also on owner's pocket. Water-Energy nexus is new approach develop in recent year to understand relation between them. With development of this concept government policies and scheme are analysis using this approach. Public and private sector are working on nexus approach to develop new technologies which will be beneficial to mankind. Water energy nexus in early stage of development and it has greater potential for future development. Utilising this concept at very micro level will boost study in this area and development in this area will help for better future. Building has various system which are using energy and water to sever its purpose. For instance, Heating water we are using electric heater to have hot water. Different water system like taps, shower head and other such system are used for water application but this water is pumped in building using electric energy. Focusing on just efficiency of one entity will not help be as successful as looking at together. Countering leak problem for water pipe will just focus on water efficiency. However, analysing with water energy nexus will help to co-relate it with energy loss due to water leakage. The report objective is to provide base for nexus approach in building to improve overall efficiency of system. The significance of this aim can have be achieved by adopting proper procedure to analysis nexus in building. Nexus approach can lead to better outcome as they are integral part of any building. Present Scenario Global Scenario and Australian Scenario are briefly discussed below: Global scenario Research across the globe are suggesting that world is facing problem of water and energy which become more severe in upcoming years. Many studies are conducted to gather data related to severity of problem. Research suggested rapid growth is witnessed and will continue with substantial number. As consequence demand for energy and water will be at its apex. However, there are limited sources and seasonal cycle is becoming more irregular due to climate change. With rapid growth of population need for energy is also escalating day-by-day. Globally more than 40% of energy is used by building and 25% of total water. Building across the globe are responsible for one third of global Greenhouse Gas(GHG) emissions. Static suggest that main source for GHG emission is energy that is required by building for different activities [1]. Presently, most of the production for energy is by traditional methods using fossil fuel. This has great impact on environment and one of the major contributor for Greenhouse Gas emission. Australia scenario Australia is considered to be one of the driest inhabited continent of all. Availability for water for drinking, day to day use and for agriculture activities are of major concern. Australia does not have fix rainfall cycle but its variable pattern as consequence to it much higher chance of drought and flood [2]. Australia is mainly dependent on its conventional source for energy generation. Coal accounts for 86% of total production whereas 13% natural gas [3]. Hence Australia needs to think out of picture to mitigate future problem that we need to face. Analysis Around 25% of total energy used by Australia is consumed by household of Australia. Australia is one the greatest per capita consumer of water with figure of 1,00,000litres per person per year. Statistics report by Australian government indicates that within 7 years we can save more than thousand million on water bills and energy bills, with electric bills by adopting more efficient system [4]. Analysing household system data suggest that cooling and heating system of building accounts for 40% of total energy. Additionally, water heating system shares percentage of 21 for Australian building total consumption and other appliances including refrigerator totally consumed around 33% [5]. Source for fresh water are plunging down due to changes in variability in rainfall cycle. More consumption leads to more production which has more severe impact on environment. If care is not taken or same situation prevails for a period than consequence may be severely unacceptable. However, there are chance and much scope for improvement to resolve problem in future. Some suggestion made are described in methodology section. Methodology The report is based on Qualitative approach in which case study is discussed to come to a conclusion. Data are based on different source with a case study to discuss nexus at building level. Till now discussion was on understanding of Water-Energy nexus and why is it important. Further report will describe about a case study to draw discussion to derive result. Form the above argument we can lead to the conclusion that one of the major systems which needs to improve is Heating and cooling system. Importance of system and relative case study is explained below. Heating and Cooling System (HVAC system) As discussed earlier in report it is the major consumer of electricity. Traditional Heating Ventilation and Air Conditioning System (HVAC system) consumes high amount of energy and water as well. Water is required in cooling tower and Australian government report suggest that billions of litres water is used in cooling tower of HVAC system. Data also suggested that around 9% of total generated energy in Australia is consumed by HVAC system. By acknowledging this issue government of Australia has come up with new strategy called the Heating, Ventilation and Air-Conditioning High Efficiency Systems Strategy (HVAC HESS). The objective of this strategy is to improve overall efficiency HVAC system across Australia. HVAC system has direct use of water and energy as they are linked as water is used in cooling to and energy is required to run the HVAC system. Case study of HVAC system A case of Commercial Building on 4 Mort Street, Canberra is discussion in report under HVAC HESS strategy [6]. Here building went under retrofitting work to upgrade efficiency of current HAVC system. Building age is 45 years and was declared 2.5 star on energy rating under NABERS which was upgrade to 4.5 star. The building is 5 storeys and was having problem in their HVAC system. Energy audit was conducted to get information about energy consumption of building. The audit found that ninety percent of base energy was accounted by HVAC system. Figure 1 (a) Chilled water buffer vessel (b)Insulated heating hot water pump and pipe work Figure 1(a) shows picture of chilled water buffet vessel which was install in to enhance cooling system. This was accompalnished by modern and high accuracy Building Management system (BMS) and Variable speed drivers(VSD). In existing system poor economic cycle was prevailing which was consuming more energy and decrease performance of HVAC system by 20%. This systm was replaced by Air handling system which uses available air from atmosphere for cooling when its favourable. Motorised dampers were installed on each floor for economic and selective use when air conditionning is required. Before retrofitting work Consdtant volume air distribution system was working which was changed to Variable air volume(VAV) system. Chiller of old reciprocating type was upgradede to high efficiency machine. Figure 1(b) shows pictiure of insulated heating hot water pump. This system is backbone for heating system of VAC system. Hot water pump regulates hot water from boiler and through system. Insulation was provided to stop heat loss in system which result into high efficiency.This insulation was just not on pipe of water pump but on whole pipe structure with air duct having value of R more than 1.8m2K/W.In retrofiting work condensing type of boiler was used recommended and used. Audit suggested that electricity is bad option for heating than it was changed to gas as fuel option. Discussion on Result Drastic improvement is witnessed in case of retroffiting of HVAC system. Retrofitting work was carried out with aim of 4.5 star NABERS energy rating which was achevied with compeltion of project in November 2010. Studied showed that annually now they can save upto $120,000 and much on water bills. With the improvement in HVAC system proerty value is raised to $1.4million. Apparently now than have reduce GHG emission by 70% which is equal to 786 tonnes of carbon dioxide gas. Upgrade system has provision of zoning system which has enhanced comfort level of tanents.The intial cost of retrofiting was $1.5 million with saving of $120,000 annually, so the intial cost can be incurred within 12.5 years. Analysising outcome of result by improving HVAC system not only proves beneficial on saving but it can also reduce GHG emission. Australian government with HVAC HESS strategies have initiated steps towards better future with upgrading current systems. As discuss in case they have installed modern management system in HVAC which will monitor air flow, water flow, Electric consumption etc. This will help to save electric energy with water and bigger scale on Australian aspect. Current HVAC system should be analysed and can make changes according to requirement. Conclusion and future work The case study provide base for HVAC system. This study leads to a conclusion that by employing more efficient technology and upgrading current system, it helps to achieve goal of environmental sustainability and cost saving. Similarly Water energy nexus can be applied on other system like water heating system to enhance performance for cost saving. If same nexus approach is applied on each system of building then result can bring significant changes in environment. From this we can say that,the water energy nexus will be foundation for efficient system employment on building level with benefits to assosiated people and to surrounding. The Water energy nexus approach is just at early stage of development and will develop with futher development of concept. Nexus study will change approach in selection of efficient system considering water and energy both in mind. New technologies are develop like Shower head mounted with music system to reduce shower time. Concept is to play music for desired time to acknowledge user. This is future concept on trial basis, which is initiated by Water energy nexus approach. Reference 1. Initiative, C., Buildings and Climate Change. 2009. 2. ; Available from: http://www.skwirk.com/p-c_s-16_u-140_t-414_c-1449/water-management/nsw/water-management/issues-in-australian-environments/geographical-issues-physical-environments. 3. Regulator, A.E. STATE OF THE ENERGY MARKET 2014. 2014 [cited 2015; Available from: https://www.originenergy.com.au/blog/about-energy/energy-in-australia.html. 4. Heating, Ventilation and Air-Conditioning High Efficiency Systems Strategy (HVAC HESS) I.a.S. department of Industry, Editor., Australian Government: Australia. 5. McGee, C., Energy - Australian guide to Environmentally sustainable Homes. 2013. 6. Case Study - Commercial Building Energy Efficiency Retrofit – 4 Mort Street, Canberra. 2010.