condensate recovery in mutrafiah project

CONDENSATION RECOVERY QURANIC GIRL INTERMEDIATE SCHOOL CASE STUDY, JUBAIL KINGDOM OF

SAUDI ARABIA

PREPARED BY: MUDASSAR IDRIS RAUT – LEED GREEN ASSOCIATE

1.1 ABSTRACT

The biggest reliable source of potable water in Saudi Arabia is from Desalination Water

treatment. Since Ground source water resources are very minimal due to geographical location,

country largest demand depends on Desalination water from Sea. However the production cost to

convert saline water to Potable water is considerable [1.09 US$ per cubic meter]. Since water is

very crucial for daily activities & converting Saline Water into potable consume ample amount of

energy & money, it obviously increases an alarm to reduce water consumption at site & look for

other replaceable derivatives which can replace Potable water intake from Municipal Bodies. The

Saudi Minister of Water & Electricity estimated that 25% of Saudi Oil & Gas Production in fiscal yr.

2009 was used domestically to generate electricity & produce water, with present demand rates

suggesting that this figure will reach 50% by yr. 2030 as per research by [BELFER CENER for science

& International Affair].

To focus on this cause Mechanical Engineering Division of Abdul Al Rahman AL Naim

Consultant- Dammam has developed a conceptual design for Water Reclaim use at Quranic School

Project- a Royal Commissioning Project in Jubail, Kingdom Of Saudi Arabia.

1.2 BACKGROUND STUDY ON CONDENSATION

Proposed HVAC system designed is of Chilled Water System where in there are 5 No’s Air

Handling Unit used in Girl Intermediate School & 2 No’s Air Cooled Chillers. Since this schools are

located in Jubail where there is enough amount of humidity present in air, the water present can

be used after condensation. As per ASHRAE [American Society Heating Refrigeration & Air

Conditioning Engineers] standards school requires larger amount of outside air to main inside

school environment healthy. Now this outside brings large load on Air Handlers Cooling Coils in

turn increasing the amount of moist air passing through these Coils. As this air passes through

these coil, temperature of air drops as a result the air can no longer holds the amount of moisture

as it was holding when it was relatively hot. This process can easily be understood in Psychometric

analysis of Air handling units. As a result the moisture present in moist air drops off & this entire

process is called Condensation. Note that not all the moisture present in moist air drops as there

is still resultant moisture present in air leaving the cooling coil. The exact theoretical amount of

moisture required depends on Indoor Desired room condition: - In this case we are maintaining

50% relative humidity as commanded by ASHRAE standards for school project & it also complying

with our client Royal Commission Design basis Reports [DBR]. This process is explained in below

fig. 1.1

http://belfercenter.hks.harvard.edu/files/Kajenthira-Anadon-Siddiqi%20--%20Wastewater%20Reuse%20in%20Saudi%20Arabia.pdf

http://belfercenter.hks.harvard.edu/files/Kajenthira-Anadon-Siddiqi%20--%20Wastewater%20Reuse%20in%20Saudi%20Arabia.pdf

1.3 WHAT IS CONDENSATE WATER?

Condensate is a byproduct generated during Air Conditioning process which is

usually wasted & drained to sewer. Condensate is generated in the same manner as distilled

water, which has a slightly acidic pH value around 5.8, as compared to a neutral pH value of 7.0,

and contains no minerals. However, unlike distilled water, condensate is subject to environmental

contamination during the process of collection and transport. Microorganisms (e.g., bacteria and

viruses) suspended in air drawn from inside and/or outside the building (i.e., return air and/or

outside air) through the Air Handling Unit (AHU) can collect on the cooling coils with the moisture

when condensate is formed (see Fig 1.1 for a schematic of an AHU). In addition, being slightly acidic,

condensate tends to react with materials with which it comes in contact. Such reactions can raise

the pH value of condensate. Any molecules or particulates the condensate picks up during

formation or along its flow path can be referred to as a contaminant and must be considered when

making treatment decisions.

Fig: 1.1

1.4 ACCUSTOMED CONDENSATE PRACTICES

Largely the condensate collected is discarded through various drain points & dumped into

normal sewers. This not only waste this high valuable clean Distilled water but also adds loads in

Sewer Treatment Plant on Local municipal bodies thus increasing additional Energy & Cost factors

to the Government. This not only burden the Government organization but also results in

additional GHG [Greenhouse Gas] emission into environment.

Fig: 1.2

1.5 CONDENSATE WATER APPLICATION

Can be used in 3 main Domain.

1. COOLING TOWERS.

2. TOILET FLUSHING.

3. LANDSCAPE IRRIGATION & HARDSCAPE CLEANING.

The most effective use of condensate water collected from commercial or industrial

buildings is for makeup water in cooling towers. This is because the pure and cool condensate water

dilutes the sediment buildup in cooling towers (the sediment is left behind during the evaporative

cooling process), increases the efficiency of the cooling towers by virtue of its relatively cool

temperature, provides the most water in hot and humid conditions when makeup water for the

cooling towers is most needed, and requires no additional storage or treatment.

Other common uses of condensate include toilet flushing, irrigation, ornamental water features,

and process water, such as that used in manufacturing. Designing for these uses requires a water

budget to determine how much water is produced (supplied) versus how much is required

(demanded) for the intended purpose. Storage is required if the water produced cannot be

immediately used for its intended purpose. This is the case with most applications except for

cooling towers and perhaps some process water and irrigation applications, depending on exact

needs. Treatment in the form of filtration and disinfection is used to raise the quality of the water

for its intended application. Applications in which reclaimed water could conceivably come in

contact with human skin or be ingested require the highest-quality water. In all cases, a well-

designed and well-maintained HVAC system is critical to the production of condensate that is free

of microbial buildup or other contaminants

Except for Cooling Tower usage, local codes or AHJ Authority Having Jurisdiction & International

Code like IPC, IBC should be followed if condensate water is to be used for application involving

direct human contact or some time ingestion. Also a detail water report must be conducted on

monthly basis to study the acidic nature or micro Organism growth of condensate collected for

other uses. Because this acidic nature may harm the Toilet ceramic if repeatedly used or it may

harm landscape, Lawn Sprinklers, Drip irrigation pipes, Pumps, Fountains etc. For best result a

strict maintenance of AHU equipment is required on weekly/monthly basis from Maintenance &

Operation Contractor.

BECAUSE THERE ARE NO COOLING TOWERS IN QURANIC PROJECT, OPTION-2 & OPTION-

3 ARE LEFT TO BE IMPLEMENTED. HOWEVER PROPOSED CONCEPT IN THIS REPORT IS

OPTION-2 i.e TOILET FLUSHING

1.6 HOW MUCH CONDENSATE WATER CAN QURANIC

INTERMEDIATE SCHOOL GIVE?

There are 5 No’s AHU in Quranic Girl Intermediate School & condensate generated in

Gallons by these AHU’S are given in below Table 1.1.

There are various technique to capture condensate Flow Volume & Engineers & researchers have

developed certain Thumb rules even based on Tonnage & Sq Ft Area to be Air Conditioned.

However we have captured theoretical data from HAP [Hourly Analysis Program] Software based

on thermodynamic relation below.

QC= Qa X DENSITY X (W1-W2) X 0.45 X 0.2641 X 60-----

Where,

QC – Gallons/Hr. of Condensate.

Qa = Air Flow rate of mixed air [Return + Outdoor] in CFM

Density - Stds Density of Air = 0.075 lb/ft3 at atmospheric Pressure.

W1 - Specific humidity of Mix Air Entering Cooling Coil.

W2 – Specific humidity of Cool Air Leaving Cooling Coil.

& 0.45, 0.2641 & 60 are conversion factors to be used to get values in Gallon/Hr.

AHU-01 AHU-02 AHU-03 AHU-04 AHU-05

JAN 2,769 3,028 3,137 3,151 2,073

FEB 4,789 6,900 6,051 6,227 4,224

MAR 4,194 5,674 5,942 5,939 3,839

APR 4,103 5,743 6,010 5,969 3,756

MAY 5,072 7,837 7,977 7,761 4,745

JUN 6,047 9,502 9,926 9,597 5,794

JUL 1,373 2,158 2,256 2,182 1,317

AUG 6,007 9,468 9,922 9,612 5,787

SEP 3,445 5,266 5,523 5,470 3,273

OCT 6,425 9,388 9,823 9,134 5,990

NOV 5,890 8,042 8,390 8,457 5,422

DEC 2,515 3,034 3,147 3,275 2,212

TOTAL GALLONS/YR BY

AHU

52,629 76,039 78,104 76,772 48,431

TOTAL GALLONS/YR BY ENTIRE SCHOOL

331,977 GALLONS/YR

Table: 1.1

1.7 CONDENSATE CALCULATION PROCEDURE

Temperature Simulation file of Jubail is recorded from HAP file. The hottest day in particular

month is recorded for which the condensation is calculated. The Maximum & minimum Dry Bulb

temperature is recorded from HAP file for which W1 & W2 is recorded. Also in spite of recording

24 hrs. data for entire day only 13 hrs.[From 5 AM to 5 PM] data is recorded for that particular

hottest day in a particular month. 13 hrs. data is then added to get daily data & finally this Hottest

day data is multiplied with 70% diversity factor assuming all the condensate generated for

remaining days will always generate less amount of condensate. Also it is assume that each month

have 30 days immaterial of JFMAMJJASOND series. This all assumption are just for ease in

calculation as hourly condensate generated for all 365 days will take ample amount of time &

perhaps the exact & correlated values will have minimal variations.

W1 & W2 is recorded for every 13 hr. from HAP Psychometric Analysis procedures which shows

every 13 hrs. in every single month. Based on these value & Air flow rate of particular AHU the final

Qc value is recorded for every Single hours in those 13 hrs. study. Then all 13 hrs. resulted are

summoned up to get final day value of condensate on that particular day.

Fig: 1.3

Sample Calculation for January month for AHU-3 is as shown Below in Table-1.2

TIME W1 @ TM W2 @ T0 LPM GPM GPH GPD MONTHLY

JAN

500 0.00864 0.00769 0.52 0.14 8.29

209.14 3137.17

600 0.01105 0.00879 1.24 0.33 19.73

700 0.01105 0.00874 1.27 0.34 20.16

800 0.01107 0.00877 1.27 0.33 20.08

900 0.01104 0.00869 1.29 0.34 20.51

1000 0.01104 0.00869 1.29 0.34 20.51

1100 0.01102 0.00864 1.31 0.35 20.77

1200 0.01103 0.00863 1.32 0.35 20.95

1300 0.01101 0.0086 1.33 0.35 21.04

1400 0.011 0.0086 1.32 0.35 20.95

1500 0.00864 0.00764 0.55 0.15 8.73

1600 0.00807 0.00763 0.24 0.06 3.84

1700 0.00806 0.00765 0.23 0.06 3.58

LPM- Liters Per Minute

GPM – Gallon Per Minute

GPH- Gallon Per Hour

GPD- Gallon Per Day

To Get Monthly data, peak load Condensation value is multiplied with Occupied Days of that

particular month [In above case January is noted (See Section 1.8).

In a similar way rest of the month data were recorded to get the results of yearly package. This data

capturing is done form all 5 No’s AHU to get the condensate generated for Entire Quranic

Intermediate School. Now as depicted from above calculation & Table-1.1 we have achieved 331,977

Gallons of Condensate.

Note that this condensate value is only theoretical figure & actual value in practice may be

low or more than this. So in order to get full proof value we have assume 50% diversity factor on

this overall value as we cannot ensure that 441,000 Gallons of condensate generated is actually

feasible at site. This final assumption is due below discussed reasons.

1. Nature is highly unpredicted as we cannot ascertain the values of Specific humidity W1 &

W2 we have entered from HAP analysis is exactly possible at site.

Table: 1.2

2. The above data is when the building is occupied on full load & all Chillers are running on

peak Load. But this usually happens for only small amount of time & most of the time the

building is HVAC system is not running on full load.

3. AHU cooling coils must be perfectly clean & well maintained through the year as we cannot

guarantee the Exact Condensate generated with Poor maintained Cooling Coil.

Moreover under worst case scenario even if we fail to get enough condensate, the proposed design

system by ACE Consultant is flexible enough to take in account Potable water as a back water to

flush the toilets. So the proposed design ensures that Human Comfort will not be disturbed by

implanting Condensate Water system for water flushing. So for Royal Commission it’s a Win-Win

situation where in they can not only save Water used at site but also end up in paying Less Water

& Tax to Govt municipal Bodies.

Fig-1.4 shows a comparison between theoretical & diversified Condensate values.50% diversity is

just a factor of safety to cushion our design & real-time values at site may exceed this diversity

factor.

7,079

14,09512,794 12,791

16,696

20,433

4,643

20,398

11,488

20,38018,100

7,091

14,158

28,191

25,588 25,582

33,393

40,866

9,286

40,795

22,977

40,759

36,200

14,182

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

GA

LL

ON

S

MONTHS

HVAC CONDENSATION COMPARISION BETWEEN THEOROTICAL &50% DIVERSITY FOR QURANIC GIRL INTERMEDIATE SCHOOL

Fig: 1.4

1.8 SCHOOL HOLIDAYS

SEP – 9 TO SEP – 17---------EID AL ADHA HOLIDAYS

DEC-16 TO JAN- 7----------WINTER BREAK

MARCH – 24 TO APRIL – 8-----SPRING BREAK

JUNE – 20 TO JULY – 29 ---------SUMMER BREAK

Above holiday structure is taken from KAUST[King Abdulla University of Science & Technology-

Thuwal]. Although holiday structure of University is followed, this holiday structure is subjected

to change as per Royal Commission School guidelines.

For all these holidays, school is considered to be completely shut down where in there is no

HVAC Equipment running & also there is no Occupant load in School to use Toilet Flushing. Also

it is assume that a month will have only 22 days of occupancy excluding all weekend.

Note that for this reason among 3 Basic uses of condensate water , we have opted to use condensate

water for Toilet Flushing because even if school is shut down we need water to maintain Landscape

but on contrary we don’t need water to flush toilets as there is no Occupant Load in toilets during

vacation period.

A detailed graphical representation will help in explaining the Holiday Structure & Occupancy

Load. It is quite important to note at this stage, for Water budget estimating for flushing, we will

use this same occupancy load to balance demand water for Toilet flushing with produced

condensate water.

1.9 WATER BUDGET

One of the prime motive to develop water budget is to estimate the Water demand used for

flushing of Water Closet. We are using highly efficient Toilets in this school with flush rate ranging

from 0.8-1.28 Gallons/Flush.

Quranic Girl Intermediate School is divided into 5 Zones for both HVAC & plumbing

Calculations. The detail Sub-Division of these zone is shown below in figure-1.51

Fig: 1.5

Total number of Water Closet in all Zones & their respective demand Flow volume is as shown in

Table-1.31 & Total Flushing Demand for Entire School/monthly is shown in Table-1.32

Fig: 1.51

ZONE NO'S OF WATER CLOSET

GALLONS/ FLUSH

NO OF OCCUPANT Flush/

Person/Day Flush/Day/

Zone Gallons/Day/

Zone

A 5 0.8 20 3 60 48

B 7 0.8 246 3 738 590

C 7 0.8 246 3 738 590

D 7 0.8 225 3 675 540

E 3 0.8 20 3 60 48

MONTH

NO OF OCCUPIED

DAYS

Gallons/

Month ZONE-A

Gallons/

Month ZONE-B

Gallons/

Month ZONE-C

Gallons/

Month ZONE-D

Gallons/

Month ZONE-E

JAN 15 720 8,850 8,850 8,100 720

FEB 22 1,056 12,980 12,980 11,880 1,056

MAR 15 720 8,850 8,850 8,100 720

APR 14 672 8,260 8,260 7,560 672

MAY 22 1,056 12,980 12,980 11,880 1,056

JUN 22 1,056 12,980 12,980 11,880 1,056

JUL 5 240 2,950 2,950 2,700 240

AUG 22 1,056 12,980 12,980 11,880 1,056

SEP 11 528 6,490 6,490 5,940 528

OCT 22 1,056 12,980 12,980 11,880 1,056

NOV 22 1,056 12,980 12,980 11,880 1,056

DEC 12 576 7,080 7,080 6,480 576

TOTAL GALLONS/YR/

ZONE 9,792 120,360 120,360 110,160 9,792

TOTAL GALLONS/YR FOR ENTIRE SCHOOL 370,464

Table: 1.31

Table: 1.32

1.91 DETAIL WATER BUDGET CALCULATION OF ZONE-

A FOR JANUARY MONTH

Assuming 3 flushes/day/student or staff in Girl Intermediate School

Toilet Flush & Gallons used in ZONE-A:

No of occupant = 20

Flush/person/day = 3

Flush/Day/Zone = 20 x 3 = 60

Gallons/Day = 60 x 0.8 = 48

No of Occupied days in January Month = 15 Days

Total Demand Gallons/month = 15 x 48 = 720 Gallons-----------A

Available Gallons of Condensate Generated in January month for this Zone

2769 Gallons-----------------B

Assuming 50% diversity factor as discussed above in section 1.7

Total Supply Condensate = 2769 x 0.5 = 1385---------------C

[Please read Point 1,2,3 in section 1.7 to know more about this Diversity Factor]

From Equ-A & Equ-C it’s clear that Condensate generated is enough to take all the flushes

assumed & still 1385-720= 665 Gallons will be left unused for any uncertain demand.

This explains that condensate generated in January Month for Zone-A in GIRL

INTERMEDIATE SCHOOL IS SUFFICIENT TO FLUSH THESE TOILETS


B FOR JANUARY MONTH


Toilet Flush & Gallons used in ZONE-B:

No of occupant = 246



Gallons/Day = 738 x 0.8 = 591




3028 Gallons-----------------B




From Equ-A & Equ-C it’s clear that Condensate generated is not enough to take all the

flushes assumed & still 8856-1328= 7528 Gallons will be additional demand.

This explains that condensate generated in January Month for Zone-B in GIRL

INTERMEDIATE SCHOOL IS NOT SUFFICIENT TO FLUSH THESE TOILETS


C FOR JANUARY MONTH


Toilet Flush & Gallons used in ZONE-C:




Gallons/Day = 738 x 0.8 = 591




3137 Gallons-----------------B





flushes assumed & still 8856-1569= 7287 Gallons will be additional demand.

This explains that condensate generated in January Month for Zone-C in GIRL



D FOR JANUARY MONTH


Toilet Flush & Gallons used in ZONE-D:




Gallons/Day = 675 x 0.8 = 540




3151 Gallons-----------------B


Total Supply Condensate = 3151 x 0.5 = 1575.5---------------C



flushes assumed & still 8100-1575.5= 6524.5 Gallons will be additional demand.

This explains that condensate generated in January Month for Zone-D in GIRL



E FOR JANUARY MONTH


Toilet Flush & Gallons used in ZONE-E:

No of occupant = 20



Gallons/Day = 60 x 0.8 = 48




2073 Gallons-----------------B




From Equ-A & Equ-C it’s clear that Condensate generated is enough to take all the flushes

assumed & still 1037-720= 317 Gallons will be left unused for any uncertain demand.

This explains that condensate generated in January Month for Zone-E in GIRL

INTERMEDIATE SCHOOL IS SUFFICIENT TO FLUSH THESE TOILETS

CONCLUSION: CONDENSATE GENERATED IN ZONE-A & ZONE-B IS SUFFICIENT TO

COVER ALL THE FLUSHING DEMANDS DUE TO LOW OCCUPANT LOAD BUT

CONDENSATE GENERATED IN ZONE-B,C,D IS NOT SUFFICIENT TO MEET THE FLUSHING

DEMAND DUE TO HIGH OCCUPANT LOAD

The Demand curve vs Condensate to support flushing Demand for all the zone is shown

below in Fig:1.6

720

1,056

720 672

1,056 1,056

240

1,056

528

1,056 1,056

576

1038

1796

1573 1539

1902

2268

515

2253

1292

2409

2209

943

0

500

1,000

1,500

2,000

2,500

3,000


GA

LL

ON

S

MONTH

ZONE-A

8,850

12,980

8,8508,260

12,980 12,980

2,950

12,980

6,490

12,980 12,980

7,080

1,514

3,4502,837 2,871

3,919

4,751

1,079

4,734

2,633

4,6944,021

1,517

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


GA

LL

ON

S

MONTH

ZONE-B

8,850

12,980

8,8508,260

12,980 12,980

2,950

12,980

6,490

12,980 12,980

7,080

1,569

3,026 2,971 3,005

3,989

4,963

1,128

4,961

2,761

4,911

4,195

1,573

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


GA

LL

ON

S

MONTH

ZONE-CFig: 1.6

8,100

11,880

8,1007,560

11,880 11,880

2,700

11,880

5,940

11,880 11,880

6,480

1,575

3,114 2,970 2,985

3,881

4,798

1,091

4,806

2,735

4,5674,228

1,637

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


GA

LL

ON

S

MONTH

ZONE-D

Fig: 1.6

From above graphical representation it’s clear that for Zone-A & Zone-E; condensate is available in

excess amount & same can be pumped to Zone – B, C, and D as required as condensate in these

Zone is not sufficient due to heavy Occupant Load. This can be well understood with Fig 1.7 which

shows condensate deficit in Zone-B-C-D.

As Zone-B is close to Zone-A, excess condensate from Zone-A can be used in Zone-B. In a similar

way excess condensate from Zone-E can be used in Zone-D. This is explained in Table: 1.4 & Fig

1.7.

This will ensure that the excess of Condensate in Zone-A, E is not wasted & in-turn used in other

zone to meet the motive of water conservation

720

1,056

720 672

1,056 1,056

240

1,056

528

1,056 1,056

576

1,037

2,112

1,920 1,878

2,373

2,897

658

2,893

1,636

2,995

2,711

1,106

0

500

1,000

1,500

2,000

2,500

3,000

3,500


GA

LL

ON

S

MONTH

ZONE-E

Fig: 1.6

EXCESS CONDENSATE

IN ZONE-A [X]

ORIGINAL CONDENSATE

IN ZONE-B [Y]

COMPENSATED CONDENSATE

OF ZONE-B [Z=X+Y]

EXCESS CONDENSATE

IN ZONE-E [M]

ORIGINAL CONDENSATE

IN ZONE-D [N]

COMPENSATED CONDENSATE

OF ZONE-D [O=M+N]

JAN 665 1,514 2,179 317 1,575 1,892

FEB 1,338 3,450 4,788 1,056 3,114 4,170

MAR 1,377 2,837 4,214 1,200 2,970 4,169

APR 1,380 2,871 4,251 1,206 2,985 4,191

MAY 1,480 3,919 5,399 1,317 3,881 5,197

JUN 1,968 4,751 6,719 1,841 4,798 6,639

JUL 447 1,079 1,526 418 1,091 1,509

AUG 1,947 4,734 6,681 1,837 4,806 6,643

SEP 1,195 2,633 3,828 1,108 2,735 3,843

OCT 2,156 4,694 6,850 1,939 4,567 6,506

NOV 1,889 4,021 5,910 1,655 4,228 5,883

DEC 682 1,517 2,199 530 1,637 2,167

8,100

11,880

8,1007,560

11,880 11,880

2,700

11,880

5,940

11,880 11,880

6,480

1,575

3,114 2,970 2,985

3,881

4,798

1,091

4,806

2,735

4,567 4,228

1,6371,892

4,170 4,169 4,191

5,197

6,639

1,509

6,643

3,843

6,5065,883

2,167

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


GA

LL

ON

S

MONTH

COMPENSATED CONDENSATE ZONE-D

Table: 1.4

Fig: 1.7

At this stage we can build the condensate use of Entire School with the total demand. This is

explained with Fig: 1.8 below.

8,850

12,980

8,8508,260

12,980 12,980

2,950

12,980

6,490

12,980 12,980

7,080

1,514

3,4502,837 2,871

3,9194,751

1,079

4,734

2,633

4,6944,021

1,5172,179

4,7884,214 4,251

5,399

6,719

1,526

6,681

3,828

6,850

5,910

2,199

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


GA

LL

ON

S

MONTH

COMPENSATED CONDENSATE ZONE-B

27,240

39,952

27,24025,424

39,952 39,952

9,080

39,952

19,976

39,952 39,952

21,792

7,079

14,09512,794 12,791

16,696

20,433

4,643

20,398

11,488

20,38018,100

7,091

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000


GA

LL

ON

S

MONTH

DEMAND VS CONDENSATE IN ENTIRE GIRL INTERMEDIATE SCHOOL

Fig: 1.7

Fig: 1.8

2.0 CONCLUSION AFTER WATER BUDGETTING.

After detailed Water Budget study, it can be concluded that if we can use

1. 100% Condensate water for Toilet Flushing we can save up to 331,977 Gallons/Yr. of Potable

water.

2. 50% Condensate water for Toilet Flushing we can save up to 165,989 Gallons/Yr. of Potable

water.

In addition it’s important to note that these thousands of Gallons is avoided both at input stage &

at Exit stage of School premises. This means

We don’t need to pump this much of saved Gallons of water from Marafiq Municipal Govt

Organization which not only guarantee reduced Water charges to Quranic Project but also

reduces Water Desalination requirement at these many Gallons of water thus helping Saudi

Arabia energy demand crisis which is discussed in Section 1.1.

We can avoid draining these many Gallons of water into Local Sewer which could have again

increased Water Treatment Cost of these many Gallons.

Lease but not less, this condensate Reclaim may look like tiny save of water when compared with

Overall Mutrafiah Quranic School Demand but still this little saving of water can assure

Sustainability & Commitment to Environment.

2.1 COST ANALYSIS A. SYSTEM WITHOUT CONDENSATE

Let us now analysis how much savings we get in terms of money. Clearly there is 370,464 Gallons

or 1403 Cu meter of annual water demand alone for flushing. If it happens to use only Potable water

alone for flushing, it would cost 8,414 SAR/Annual as per Marafiq Water Tariff in Table 1.5.

WITHOUT CONDENSATE

MONTH

Demand Gallons/ Month Entire School

Potable Water Demand CU

METER/MONTH ENTIRE SCHOOL

SAR [300 ABOVE]

CU.M 6 SAR

JAN 27,240 103 619

FEB 39,952 151 907

MAR 27,240 103 619

APR 25,424 96 577

MAY 39,952 151 907

JUN 39,952 151 907

JUL 9,080 34 206

AUG 39,952 151 907

SEP 19,976 76 454

OCT 39,952 151 907

NOV 39,952 151 907

DEC 21,792 82 495

TOTAL 370,464 1,402 8,414

Note: Water tariff are standards water tariff taken exclusively for Royal Commissioning Projects considering water consumption are always above 300 Cu Meter/Monthly

8414 SAR annual cost will be of no comparison if it needs to be compared with Condensate

Recovery System Initial Cost. Because in Saudi Arabia water is charged at very low compared

with a price its produced at Desalination Plants. This extra amount Govt is subsidizing from over

exempting on its citizen & delivering water at very low tariff. This is why we cannot get a Pay Back

period for our Condensate Recovery System with actual Marafiq Tariff as this system obviously

will exceed 8414 SAR overall Cost even for a Payback Period of 5 yrs.

So to get a clear picture let us bring additional Cost for Sea Water Desalination & Water Treatment

to be done to this 1403 Cu meter water, so that this water to be eligible for Potable Water.

Note that this additional cost Saudi Govt is paying for every Cu Meter to convert Sea Water into

Potable water & treat Sewer after being used.

Table: 1.5

A Potable Water Cost: 8414 SAR--------------------------A

B. Cost of Desalination=4.08 SAR/Cu Meter [1.09 US$/CU Meter]

Total Cost = 4.08 x 1403 = 5724 SAR ------------------------B

C. Cost Of Water Treatment = 7.45 SAR/CU Meter [1.98 US$/CU Meter]

Total Cost = 7.45 x 1403 = 10,452 SAR-------------------------C

TOTAL COST = A +B + C = 8414+5724+10,452 = 24,590 SAR /Annual.

B. SYSTEM WITH CONDENSATE

Assuming 50% condensation, we noticed that we have 165,989 Gallons of

Condensate. Table 1.6. & additional we need 774 Cu Meter of potable water

for complete flushing. This comes with an expense of 4644 SAR/Annually.

A Potable Water Cost: 4644 SAR--------------------------A

B. Cost of Desalination=4.08 SAR/Cu Meter [1.09 US$/CU Meter]

Total Cost = 4.08 x 774 = 3158 SAR ------------------------B

C. Cost Of Water Treatment = 7.45 SAR/CU Meter [1.98 US$/CU Meter]

Total Cost = 7.45 x 774 = 5766 SAR-------------------------C

TOTAL COST = A+B + C = 4644+3158+5766 = 13,568 SAR /Annual.

Table: 1.5

TOTAL COST SAVINGS: 24,590 – 13,568 = 11,022 SAR/ANNUALLY

TOTAL WATER SAVINGS: = 165,989 GALLONS/ANNUALLY

WITH CONDENSATE

MONTH

Demand Gallons/ Month Entire School

Gallons OF 50% Condensate/

Month Entire School

POTABLE WATER CU

METER/MONTH ENTIRE SCHOOL

SAR [300

ABOVE] CU.M 6 SAR

JAN 27,240 7,079 76 458

FEB 39,952 14,095 98 587

MAR 27,240 12,794 55 328

APR 25,424 12,791 48 287

MAY 39,952 16,696 88 528

JUN 39,952 20,433 74 443

JUL 9,080 4,643 17 101

AUG 39,952 20,398 74 444

SEP 19,976 11,488 32 193

OCT 39,952 20,380 74 445

NOV 39,952 18,100 83 496

DEC 21,792 7,091 56 334

TOTAL 370,464 165,989 774 4,644

Note: Water tariff are standards water tariff taken exclusively for Royal Commissioning Projects considering water consumption are always

above 300 Cu Meter/Monthly

CONDENSATE RECOVERY SYSTEM COST:

PAYBACK PERIOD:

Table: 1.6

2.2 BASIC DESIGN

Concept of Initial Design is made simple with the use of 2 No’s Condensation Tank. Exact

tank sizing & Pipe Sizing is not done at this stage of design as the whole Condensate Reclaim

Engineering need prior approval from Royal Commissioning.

2 tank concept is used to overcome all the unpredicted condensation thus adding more

safety & reliability. Tank-1 is designed to hold 1 week condensate & Tank-2 is designed to depend

on Tank-1 to meet the Flushing demand. Also 2 or more Zones can be combined to use this Dual

Design concept. Tank-1 can hold 1 week condensate demand to feed the Flushing requirement in

School. Float switch installed in Tank-2 is preset between Upper & Lower layer; where in lower

layer is set for at least 1 day Flushing Demand of Zones involved in that design

Fig-1.9 explain the schematic layout of typical Condensate Collection System.

NOTE:

1. To capture the flow of condensate Water Metering may be required. This will be

mandate if any building is applying for LEED Certification; as per LEED V4 is concerned

Building Level Water Metering is both Pre-requisite & Credit. However in this proposed

designed we have not included any Water meters since Quranic Project didn’t applied

for any LEED certification.

2. It will be an optional step to use water treatment depending on the pH value of the

condensate. If pH reduces drastically then a chlorine Dosing tank along with pH sensor

installed & interlocked with dosing tank may be used. It all depends on pH value of

condensate at the time of Commissioning Phase.

SEQUENCE OF OPERATION

Float switch in Tank-2 after reaching at lower level sends a control signal to Motorized

Valve-1 through Control Logic Panel-1[CP-1]. This will activate the valve to open & condensate

collected in Tank 1 reaches Tank-2. This flow is sensed by Flow-Switch installed & this in turn gives

a Control Logic Signal to Motorized valve-2 to get closed.

If the Motorized Valve-1 open & there is no condensate in Tank 1; then in this case the Flow Switch

will send signal to Motorized Valve-2 to open through Cp-2. This will activate Potable Water Feed

in Tank-1 & once upper level is reached Potable water is stopped.

CP-1 & CP-2 are interlocked to control Potable Water feeding.

2.2 CONDENSATE RECOVERY & GREEN PLUMBING

MECHANICAL CODE.

Because condensate is onsite Water recovered water we need to follow extra code apart from

usual IPC/ASPE Standards & Code. AS a practice we have followed [IAPMO] Green Plumbing

Mechanical Code Supplement 2012. This code help is additional safety & further design &

Commissioning input that must be adhered in addition to IPC Code.

Fig: 1.9

Fig 503.9 is a reference from Sec: 503.7 explaining the signage required in Reclaimed Water

services. As far as Water quality is concerned of recovered Condensate water, Section: 504.10

DESIGN & INSTALLATION direct AHJ [Authority Having Jurisdiction] or local code for further

treatment before any end use on Toilet flushing.

2.3 INSTALLED SNAPS FOR REFRENCE

REFERENCE:

Review of Saudi Arabia Municipal Water Tarif- Omar K M Ouda, Department of Civil

Engineer, Prince Muhammad Bin Fahd University, Al Khobar, Kingdom Of Saudi Arabia.

Hourly Analysis Program Software Specific Humidity results for Quranic Girl Intermediate

School- Mutrafiah Project, Al Jubail- Kingdom of Saudi Arabia Designed by Abdul Rahman

AL Naim Consultant Engineers- Dammam, Kingdom Of Saudi Arabia.

San Antonio- United States of America- User Manual for Condensate Collection & Use

Manual for Commercial Buildings.

ASHRAE Journal on Condensate Recovery System by Karen Guz Vol 47, no-6 Published on

June 2005.

White paper by Belfer Center for Science & international Affairs on Waste Water Reuse in

Saudi Arabia by Arani, Laura Diaz & Afreen Siddique.

Engineers Newsletter by TRANE Vol 36-4 for FAQ on LEED & HVAC design for

sustainability.

2012 Green Plumbing & Mechanical Code Supplement; Second Edition.

American Society of Plumbing Engineer; Vol-2 for Water Purification stds & treatment.

condensate recovery in mutrafiah project

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