Prepared by: Central of Viet Nam Technologies JSC

Prepared by: Central of Viet Nam Technologies JSC

Table of Contents I. INTRODUCTION... 3 II. SURVEY FINDINGS... 3 1. Scope of the Survey... 3 2. Methodology... 8 3. Result Analysis... 9 3.1. Basic information about highrise buildings... 9 3.2. Water consumption in the buildings... 10 3.3. Warm water generation... 13 3.4. Wastewater discharge... 15 III. CONCLUSION... 16 IV. APPENDIX... 17 Appendix A - Collected Questionnaires of 14 Highrise Buildings (see attached)... 17 Appendix B - Data Summary (Excel Spreadsheet) (see attached)... 17 List of Tables Table 1 Total apartment area of the buildings... 10 Table 2 How water consumption is metered in the buildings... 10 Table 3 Correlation between number of floors and average water consumption... 12 Table 4 Where wastewater is discharged... 15 List of Figures Figure 1 - Total floors vs. Total apartments... 9 Figure 2 How water consumption is metered... 11 Figure 3 Correlation between number of floors and average water consumption... 13 Figure 4 - Energy used for generating warm water... 14 Figure 5 How warm water is generated in highrise buildings... 14 Figure 6 Where wastewater is discharged... 16 1

Executive Summary The survey at highrise buildings in Da Nang Eastern coastal area for the pilot vacuum sewer system is provided by Central of Vietnam Technologies Joint Stock Company as a commission to GIZ-Nexus project. This summary report of the survey focuses on summarising and analysing related information of highrise buildings in the Eastern coastal area as a basis for further investigation and proposal of the pilot vacuum system for highrise buildings in this selected area. 2

I. INTRODUCTION As part of the Nexus project in Da Nang city Vacuum waste water collection, waste water treatment (biogas production) using the by-products (irrigation water and fertilizer from biogas plant) for urban agriculture, the objective of this survey is to provide an overview about the current situation of highrise buildings in the Eastern coastal area of the city with an emphasis on water consumption, energy used for generating warm water and wastewater discharge. II. SURVEY FINDINGS 1. Scope of the Survey Before conducting the survey, a pre-survey on-site visit to the Da Nang Eastern coastal area to investigate and select the buildings which match the set criterion as a highrise building from 10 storeys and above. The pre-survey has located the following 14 highrise buildings as in the illustrated mapping, including hotels and condominiums: 3

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In a closer look, the 14 highrise buildings in the area are: Van Son Hotel Sun DC Hotel Angel Hotel Tu Son 2 Hotel 5

Monaco Hotel Harmony Condominium Thanh Binh Xanh Condominium Misa Hotel 6

Luna Diamond Hotel Truong Son Tung Hotel Grand Mango Hotel Starlet Hotel 7

Fansipan Hotel Azura Luxury Apartment Tower 2. Methodology With the support from Department of Planning and Investment of Da Nang city (DPI), the questionnaires had been sent to the related highrise buildings for preparation them prior to the interviews and onsite visits conducted in the late mid of March 2014. The information was collected directly with the representative respondents from the respective highrise buildings. All 14 questionnaires were recorded complete (please refer in details in Appendix A). Since the data were collected from representatives of the respective highrise buildings, during the summarising and analysing phase, data were cross-checked for correction and refined if needed. 8

3. Result Analysis 3.1. Basic information about highrise buildings Figure 1 - Total floors vs. Total apartments Number of floors Number of apartments 225 128 91 40 45 53 60 30 40 50 60 60 71 47 10 10 11 11 11 12 12 12 12 12 14 16 17 34 Figure 1 - Total floors vs. Total apartments Figure 1 has shown some basic information with regard to number of floors and total number of apartments about the 14 highrise buildings in the Eastern coastal area of Da Nang city. In general, condominiums and apartment tower have more floors and total apartments compared to other highrise buildings. Particularly, Azura Luxury Apartment Tower has the most floors with up to 34 floors and has the largest number of apartments with 225 apartments in total. Regarding total apartment area of these buildings, the total area of each room or each apartment ranges from 16m 2 up to 431 m 2. Specific details on total apartment area of each building are shown in the Table 1 below. 9

Table 1 Total apartment area of the buildings Name of building Total apartment area (m2) Van Son Hotel 16m2; 22m2; 40m2 Sun DC Hotel 20-25m2 Angel Hotel 18-30m2 Tu Son 2 Hotel 35m2 Monaco Hotel 17m2; 22m2; 30m2 Harmony Condominium 49.5m2; 65m2; 88m2 Thanh Binh Xanh Condominium 60m2 Misa Hotel 20m2; 24m2; 28m2 Luna Diamond 20m2; 22m2; 40m2; 80m2 Truong Son Tung Hotel 20m2; 28m2; 40m2 Grand Mango Hotel 25m2; 30m2 Starlet Hotel 28-30m3 Fansipan Hotel 25m2; 35m2; 45m2; 60m2 Azura Luxury Apartment Tower 67.3 m2 431 m2 3.2. Water consumption in the buildings With regard to water consumption, all highrise buildings have water meter. As can be seen from Table 2 and Figure 2, only 3 buildings (Azura Luxury Apartment Tower, Thanh Binh Xanh Condominium and Harmony Condominium) have water consumption metered in individual flat while the other 11 hotels which is equivalent to 79% of all buildings have water consumption metered for the total building. Table 2 How water consumption is metered in the buildings Name of buildings Water consumption metered (All Yes) For total building Individual flat Van Son Hotel 1 0 Sun DC Hotel 1 0 Angel Hotel 1 0 Tu Son 2 Hotel 1 0 10

Monaco Hotel 1 0 Harmony Condominium 0 1 Thanh Binh Xanh Condominium 0 1 Misa Hotel 1 0 Luna Diamond 1 0 Truong Son Tung Hotel 1 0 Grand Mango Hotel 1 0 Starlet Hotel 1 0 Fansipan Hotel 1 0 Azura Luxury Apartment Tower 0 1 Number of buildings 11 3 % 79 21 Figure 2 - How water consumption is metered Individual flat 21% For total building 79% Figure 2 How water consumption is metered 11

Table 3 and Figure 3 illustrate the correlation between number of floors and average water consumption for the whole building. It is easily seen from the table that Monaco Hotel ranks top in water consumption with up to 50,000 litres per day even it only has 11 floors in total. One of the reasons is compared to other recently established hotels, Monaco Hotel operated since June 2011 and there are more guests know about the hotel leading to higher occupancy rate and more water consumption. On the contrary, Harmony Condominium is still in the finalization phase and thus, the water consumption in this condominium is quite low with an average of only 3,300 litres per day. Table 3 Correlation between number of floors and average water consumption Average daily water Building Number of floors consumption for whole building (l/d) Van Son Hotel 10 20,000 Starlet Hotel 10 10,000 Grand Mango Hotel 11 7,530 Monaco Hotel 11 50,000 Sun DC Hotel 11 10,000 Thanh Binh Xanh Condominium 12 10,000 Angel Hotel 12 6,000 Truong Son Tung Hotel 12 6,900 Fansipan Hotel 12 8,000 Luna Diamond 14 12,000 Harmony Condominium 16 3,300 Tu Son 2 Hotel 17 10,000 Azura Luxury Apartment Tower 34 23,333 12

40 35 30 25 20 15 10 5 0 Figure 3 - Correlation between number of floors and average water consumption 60,000 50,000 40,000 30,000 20,000 10,000 - Number of floors Average daily water consumption for whole building (l/d) Figure 3 Correlation between number of floors and average water consumption 3.3. Warm water generation Regarding energy used for generating warm water, up to 4 highrise buildings have applied solar energy for heating water with 29% of all buildings while 71% of the buildings use electricity for generating warm water as can be seen from Figure 4. 13

Figure 4 - Energy used for generating warm water Solar 29% Electricity 71% Figure 4 - Energy used for generating warm water In additions, Figure 5 has shown that 64.3% of the buildings generate warm water in each apartment and the rest of 35.7% has centralized generating warm water. 70.0 60.0 Figure 5 - How warm water is generated 64.3 50.0 40.0 30.0 20.0 10.0 35.7 % 0.0 Centralized In each apartment Figure 5 How warm water is generated in highrise buildings 14

3.4. Wastewater discharge Table 4 and Figure 6 illustrate properly where wastewater is discharged. Overall, no highrise buildings discharge wastewater directly into sewer system. As can be seen from Table 4, only one building (Monaco Hotel) discharges wastewater into septic tank without overflow and the septic tank is emptied once per year. Moreover, there are 3 buildings equivalent to 21.4% have their own decentralized wastewater treatment plants and discharge wastewater into that. The rest 10 buildings (71.4% of all buildings) discharge wastewater into septic tank with overflow to sewer system. Table 4 Where wastewater is discharged Where waste water is discharged Septic tank without overflow Septic tank with overflow to sewer system Decentralized wastewater treatment plant Number of buildings 1 10 3 % 7.1 71.4 21.4 12 10 8 Figure 6 - Where wastewater is charged 6 4 2 0 1 Septic tank without overflow 10 Septic tank with overflow to sewer system 3 Decentralized wastewater treatment plant Septic tank without overflow Septic tank with overflow to sewer system Decentralized wastewater treatment plant 15

21% 7% 72% Septic tank without overflow Septic tank with overflow to sewer system Decentralized wastewater treatment plant Figure 6 Where wastewater is discharged III. CONCLUSION To sum up, the following survey results should be noted about highrise buildings with regard to water consumption, energy used for generating warm water and wastewater discharge: 100% of highrise buildings in the Eastern coastal area have water meter for measuring water consumption. While hotels have their water consumption metered for the whole building, the condominiums and luxury apartment tower have water consumption metered in each individual flat. Average water consumption per day ranges from only 3,300 litres up to 50,000 litres for the buildings. The water consumption rate is higher in the buildings or hotels which went into operations earlier. Regarding energy used for generating warm water, 29% of all buildings have applied solar energy for heating water and 71% of the buildings use electricity for generating warm water. In additions, 64.3% of highrise buildings generate warm water in each apartment and 35.7% has centralized generating warm water. The statistics of 4/14 highrise buildings using solar energy has shown that highrise buildings have started to consider more about energy efficiency. In the long run, if more and more highrise 16

buildings shifted to apply solar energy, it will be a sustainable method for a city with many sunny days like Da Nang. In general, no highrise buildings discharge wastewater directly into sewer system. Only one building discharges wastewater into septic tank without overflow and the septic tank is emptied once per year. In additions, three buildings equivalent to 21.4% discharge wastewater into their own decentralized wastewater treatment plants and the rest of 71.4% of all buildings discharge wastewater into septic tank with overflow to sewer system. IV. APPENDIX Appendix A - Collected Questionnaires of 14 highrise Buildings (see attached) Appendix B - Data Summary (Excel Spreadsheet) (see attached) 17