Army Sustainability Workshop

PRESENTED BY LEBANON GREEN BUILDING COUNCIL(LGBC)

N OV EM B ER 1 2 – 1 3 – 1 9 D EC E M B ER 1 & 8

VRF VS CHILLED WATER SYSTEMS LOW RISE RESIDENTIAL BUILDING – DUBAI: CASE STUDY

PRESENTED BY, ENG. ELIE FADOUS

CONTENTS1. OBJECTIVES

2. METHODOLOGY

3. PROJECT DESCRIPTION

4. COOLING BLOCK LOAD

5. HVAC SYSTEMS DESCRIPTION: AIR COOLED CHILLER, VRF-OPTION I, VRF-OPTION II

6. INITIAL COST

7. RUNNING COST

8. MAINTENANCE AND SPARE PARTS

9. LIFE CYCLE COST

10. ANALYSIS: TECHNICAL, FINANCIAL AND MAINTENANCE MANAGEMENT

1 - OBJECTIVES

Assess the merits of an Air conditioning system

Comparison between Air cooled chilled water system and : A) Roof located VRF outdoor units; B) Floor located VRF outdoor units

How and what would be the benefits?

2 - METHODOLOGY

Load calculation will be based on an Hourly analysis program

Load calculation profile will be an hourly profile covering the entire year

Selection of equipment (High ambient temperature)

2 - METHODOLOGY AC systems layouts, schematic risers and schedule of equipment

Detailed yearly Electrical power inputs schedule

Life cycle cost comparison table

Analysis Table

3 - PROJECT DESCRIPTION The project consists of:

• 1 basement used as car parks.

• GF consists of shops.

• 3 Podiums with lobbies and Tech area; the rest is used as parks.

• 1st floor that includes a health club.

• 7 typical Residential floors, each of 10 Apartments.

• Roof Floor.

• Total cooled area around: 6735m2

• Total Built up area: 15000 m2.

Typical floor plan

4 - PROJECT COOLING BLOCK LOADS Cooling Block loads have been calculated based on Hourly Analysis program

Ventilation rates are based on ASHRAE standard 62.1

Summary table:

Where:

• BL1 represents the building cooling block load.

• BL2 represents the building cooling block load with vent reclaim

Cooling loads have been done based on Dubai Weather Conditions as per Decree 66: 46C DB, 29C WB.

BLOCK COOLING LOAD KW TR

BL1 1140 325

BL2 900 255

5 - SYSTEMS DESCRIPTIONChilled water system

• 2x580 Kw=330TR Air cooled chillers (located on roof)

• Primary loop, on roof, with set of constant speed pumps: 2 pumps in duty +1 standby

• 1 set of Secondary variable speed Pumps loops (roof): 2 pumps in duty + 1 stand by

• 2 Fresh air handling units with recovery heat wheel (110 Kw or 31TR)

• AHU and FCU with 2 way modulating control.

• Chilled water pipes distribution system with insulation

• Building management system

• Energy metering system

5 - SYSTEMS DESCRIPTION

Indoor units Air cooled chillerFresh air Handling unit

5 - SYSTEMS DESCRIPTIONVRF system option 1 (Roof outdoor units)

• 24 VRF Outdoor units located on roofhaving a total corrected load of 1250 kw

• 152 VRF indoor units

• 2 DX Fresh air handling units with recovery heat wheel (110 Kw or 31TR)

• Refrigerant copper pipes with insulation

• Intelligent controller system including power proportion distribution (PPD) system for energy metering.

5 - SYSTEMS DESCRIPTIONVRF system option 2 (Same floor outdoor units)

• 24 VRF Outdoor units located on the same floor having a total corrected load of 1250 kw

• 152 VRF indoor units

• 2 DX Fresh air handling units with recovery heat wheel (110 Kw or 31TR)

• Refrigerant copper pipes with insulation

• Intelligent controller system including power proportion distribution (PPD) system for energy metering.

5 - SYSTEMS DESCRIPTION

Indoor units Outdoor unitFresh air Handling unit

6 - INITIAL COST

Chiller system VS VRF system (Option 1)

• Chiller Option - Initial cost is around $1,109,609

• VRF option 1 - Initial cost is around $1,519,000

Increase in installed cost of VRF Option 1

vs Chiller Option :

+410,000$ = +37%

6 - INITIAL COST

Chiller system VS VRF system (Option 2)

• Chiller Option - Initial cost is around $1,109,609

• VRF option 2 - Initial cost is around $1,437,878

Increase in installed cost of VRF Option 1

vs Chiller Option :

+329,000$ = +30%

7 - RUNNING COSTThe sum of hourly running cost through a whole year leads to the yearly running cost. The calculation has been based on:

• Dubai Hourly outdoor temperature profile

• Detailed schedule showing the hourly cooling load kwh through the whole year based

• Hourly Electrical Power inputs schedule for both systems calculated via special software taking in consideration above items a and b.

• Yearly running cost has been calculated based on 0.1035 $ per Kwh

7 - RUNNING COSTDubai Hourly outdoor temperature profile (°C): Month of August (sample)

August

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

0:00 32.3 33.1 33.1 33.1 33.1 33 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1 33.1

1:00 32.1 32.4 32.4 32.4 32.4 32 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4 32.4

2:00 31.9 31.9 31.9 31.9 31.9 32 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9 31.9

3:00 31.7 31.7 31.7 31.7 31.7 32 31.7 31.7 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6 31.6

4:00 31.4 31.4 31.4 31.4 31.4 31 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4

5:00 31.3 31.3 31.3 31.3 31.3 31 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3 31.3

6:00 31.4 31.4 31.4 31.4 31.4 31 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4 31.4

7:00 31.8 31.8 31.8 31.8 31.8 32 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8 31.8

8:00 32.5 32.5 32.5 32.5 32.5 33 32.5 32.5 32.5 32.5 32.5 32.5 32.5 32.5 32.5 32.5 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6

9:00 33.6 33.6 33.6 33.7 33.7 34 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.7 33.8 33.8 33.8 33.8 33.8 33.8

10:00 35.2 35.2 35.2 35.2 35.2 35 35.2 35.2 35.2 35.2 35.2 35.2 35.2 35.2 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.4 35.4

11:00 36.8 36.8 36.8 36.8 36.8 37 36.8 36.8 36.8 36.8 36.8 36.8 36.8 36.8 36.8 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9 36.9

12:00 37.9 37.9 37.9 37.9 37.9 38 37.9 37.9 37.9 37.9 37.9 37.9 37.9 37.9 37.9 37.9 38 38 38 38 38 38 38 38 38 38 38 38 38 38 38

13:00 38.6 38.6 38.6 38.6 38.6 39 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6

14:00 38.9 38.9 38.9 38.9 38.9 39 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9

15:00 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39

16:00 38.9 38.9 38.9 38.9 38.9 39 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9 38.9

17:00 38.5 38.5 38.5 38.5 38.5 39 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.5 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4

18:00 37.9 37.9 37.9 37.9 37.9 38 37.9 37.9 37.9 37.9 37.9 37.9 37.9 37.9 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8

19:00 37.2 37.2 37.1 37.1 37.1 37 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1 37.1

20:00 36.2 36.2 36.2 36.2 36.2 36 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.2 36.1 36.1 36.1 36.1 36.1

21:00 35.4 35.4 35.4 35.4 35.4 35 35.4 35.4 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.3 35.2

22:00 34.6 34.6 34.6 34.6 34.6 35 34.6 34.6 34.6 34.6 34.6 34.6 34.6 34.6 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.5 34.3

23:00 33.8 33.8 33.8 33.8 33.8 34 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.8 33.4

7 - RUNNING COSTHourly cooling load schedule (KW): Month of August (Sample)

August

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

0:00 587.1 607 612.9 621.7 608 614.8 625 611 609 612 623 623 620 615 618 623 619 612 611 611 618 607 622 608 610 623 609 610 623 620 622

1:00 584 598.4 611.7 603.6 608 614.3 599 613 606 602 601 609 603 614 602 599 603 614 617 616 605 607 602 605 603 598 614 615 600 601 598

2:00 589.6 606.4 595 594.8 608 594.7 599 598 605 608 600 610 594 591 599 600 596 591 593 594 597 606 596 604 605 599 592 593 597 596 595

3:00 573.9 585.3 587.3 601.7 589 589.2 599 591 589 585 597 595 599 590 597 599 597 592 589 589 601 589 599 588 585 596 591 587 595 600 598

4:00 572.7 579.2 594.5 578.8 582 593 582 591 583 585 584 582 578 590 581 581 580 591 594 593 578 585 577 583 584 580 590 592 582 579 577

5:00 573.2 585.9 576.8 581.1 591 574.4 577 579 588 585 579 588 579 577 577 577 576 577 573 574 581 586 580 584 584 579 577 574 577 579 579

6:00 573.8 589.3 593.9 584.4 594 588.9 587 599 591 596 583 591 591 596 585 595 594 593 598 597 579 589 580 578 582 589 594 595 581 588 589

7:00 580.4 588.7 599.9 592.9 591 588.1 600 595 588 592 603 586 590 589 598 585 589 598 594 595 603 589 597 592 589 588 593 595 598 588 584

8:00 588.3 607 599.1 602.6 609 613.6 606 602 608 609 594 609 608 616 596 613 609 596 613 597 604 606 603 600 597 608 605 599 615 609 610

9:00 616.6 618.6 621.7 626.2 624 618 628 625 624 623 613 620 621 619 618 621 621 626 617 625 622 625 616 623 624 621 614 623 627 620 618

10:00 626.6 627.9 640.7 639.7 631 644.3 644 641 629 631 635 631 640 631 630 639 642 638 624 640 632 633 638 640 639 648 643 643 637 644 645

11:00 651.4 658.4 644.5 657.6 658 644.5 645 648 660 659 662 657 655 657 663 650 644 652 651 649 662 662 658 655 652 658 647 650 668 655 643

12:00 661.5 664.9 675.4 660.7 669 665.6 666 674 661 665 657 666 668 656 658 664 662 674 673 675 662 664 662 669 674 677 665 678 661 678 666

13:00 666.5 688.1 668.2 673.4 691 683 674 669 676 673 674 672 685 693 677 676 688 669 672 672 677 677 689 694 678 671 688 674 690 683 688

14:00 682.5 689.5 682.1 695.6 674 682.6 694 684 692 694 686 684 678 683 692 682 676 693 680 686 692 692 674 685 696 683 677 682 675 690 676

15:00 674.7 677.8 692.7 680.5 684 694.3 674 695 678 675 694 692 687 693 679 696 683 677 688 692 682 678 682 698 674 694 693 697 697 685 689

16:00 674.7 676.7 680.3 686.2 695 677.3 688 680 698 684 681 681 688 680 688 678 692 675 692 683 681 687 684 682 691 677 684 680 681 692 698

17:00 685.7 680.1 677.2 689.4 676 697.3 678 679 688 682 693 687 680 677 679 691 684 680 679 678 690 671 685 683 698 673 686 677 676 673 669

18:00 664.1 679.3 686.3 671.9 672 676.8 673 687 679 681 675 679 681 681 682 677 660 672 670 679 667 686 669 666 654 671 677 678 678 664 669

19:00 654.5 659.2 655.5 659.5 672 669.3 671 666 659 655 678 666 663 655 656 673 670 668 670 654 660 671 655 657 669 668 666 654 653 669 654

20:00 653.5 658.7 648.1 663.3 646 646.5 647 658 659 651 666 647 658 651 648 653 646 650 646 650 658 654 660 659 650 647 643 651 650 652 652

21:00 636.4 649.5 652 637.1 644 651.6 645 640 637 648 643 651 637 648 653 637 643 639 643 648 639 642 636 636 647 639 641 648 649 650 645

22:00 629.4 638.9 627.1 635.4 640 628.5 642 629 633 632 628 625 643 630 627 644 638 644 640 631 629 645 633 633 627 642 638 628 625 623 629

23:00 628.3 617.4 624 633 622 621 620 632 630 620 621 623 618 622 619 627 622 619 620 622 634 620 633 629 620 617 620 620 622 623 620

7 - RUNNING COSTElectrical consumption (KWh) – Chillers system: Month of August (Sample)

August

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

0:00 176.33 184.74 186.32 188.66 185.1 186.82 190 186 185 186 189 189 188 187 188 189 188 186 186 186 188 185 189 185 186 189 185 185 189 188 189

1:00 174.73 179.70 183.19 181.07 182.3 183.87 180 184 182 181 180 182 181 184 181 180 181 184 184 184 181 182 181 182 181 180 184 184 180 180 180

2:00 175.42 179.84 176.84 176.79 180.2 176.77 178 178 179 180 178 181 177 176 178 178 177 176 176 176 177 180 177 179 179 178 176 176 177 177 177

3:00 170.51 173.51 174.03 177.82 174.5 174.53 177 175 174 173 176 176 177 174 176 177 176 175 174 174 177 174 177 174 173 176 175 173 176 177 177

4:00 169.02 170.73 174.75 170.62 171.5 174.36 171 174 172 172 172 171 170 173 171 171 171 174 175 174 170 172 170 172 172 171 174 174 171 171 170

5:00 168.76 172.10 169.70 170.83 173.4 169.07 170 170 173 172 170 173 170 170 170 170 169 170 169 169 171 172 171 172 172 170 170 169 170 170 170

6:00 169.31 173.38 174.59 172.09 174.7 173.28 173 176 174 175 172 174 174 175 172 175 175 174 176 175 171 173 171 170 171 173 175 175 171 173 173

7:00 172.61 174.79 177.74 175.9 175.3 174.64 178 176 175 176 178 174 175 175 177 174 175 177 176 176 179 175 177 176 175 175 176 176 177 175 174

8:00 177.43 182.35 180.28 181.2 182.9 184.09 182 181 183 183 179 183 183 185 179 184 183 180 184 180 182 183 182 181 180 183 182 181 185 183 183

9:00 189.35 189.89 190.72 192.33 191.8 190.14 193 192 192 191 189 191 191 190 190 191 191 192 190 192 191 192 190 192 192 191 189 192 193 191 191

10:00 198.68 199.04 202.52 202.25 199.9 203.5 203 203 199 200 201 200 202 200 200 203 203 202 198 203 201 201 202 203 203 205 204 203 202 204 205

11:00 212.87 214.87 210.90 214.64 214.8 210.9 211 212 215 215 216 214 214 215 216 213 211 213 213 213 216 216 215 214 214 215 212 213 218 214 211

12:00 221.46 222.51 225.76 221.21 223.8 222.72 223 225 221 223 220 223 223 220 220 222 222 226 225 226 222 223 222 224 226 227 223 227 222 227 223

13:00 226.75 233.57 227.28 228.93 234.4 231.96 229 227 230 229 229 228 233 235 230 230 234 228 229 228 230 230 234 236 230 228 233 229 234 232 233

14:00 233.46 235.69 233.34 237.64 230.8 233.5 237 234 236 237 235 234 232 234 237 233 231 237 233 234 237 236 231 234 238 234 232 233 231 236 231

15:00 231.53 232.52 237.28 233.38 234.4 237.79 231 238 232 232 238 237 235 237 233 238 234 232 236 237 234 233 234 239 231 238 237 239 239 235 236

16:00 230.98 231.62 232.76 234.64 237.3 231.81 235 233 238 234 233 233 235 233 235 232 236 231 237 234 233 235 234 233 236 232 234 233 233 236 238

17:00 232.26 230.49 229.58 233.42 229.3 235.91 230 230 233 231 235 233 231 229 230 234 232 231 230 229 233 227 232 231 236 228 232 229 229 228 226

18:00 222.26 226.96 229.13 224.67 224.7 226.19 225 229 227 227 226 227 228 228 227 226 220 224 223 226 223 229 223 222 219 224 226 226 226 222 223

19:00 215.72 217.09 215.50 216.67 220.4 219.63 220 219 216 215 222 219 218 215 216 221 220 219 220 215 217 220 215 216 220 219 219 215 215 220 215

20:00 210.65 212.11 209.13 213.41 208.4 208.68 209 212 212 210 214 209 212 210 209 210 209 210 209 210 212 211 213 212 210 209 207 209 209 210 210

21:00 202.24 205.83 206.51 202.43 204.3 206.4 205 203 202 205 204 206 202 205 206 202 203 203 204 205 203 203 202 202 205 202 203 205 205 206 204

22:00 196.91 199.47 196.29 198.53 199.8 196.67 200 197 198 198 197 196 201 197 196 200 199 200 199 197 196 201 197 197 196 200 199 196 195 195 196

23:00 193.31 190.39 192.16 194.57 191.6 191.35 191 194 194 191 191 192 190 192 191 193 191 191 191 192 195 191 195 194 191 190 191 191 191 192 189

7 - RUNNING COST SUMMARY Chiller Option: Yearly Energy Cost: $143,000

VRF Option 1 : Yearly Energy Cost: $85,600

Yearly Energy Cost Reduction

For VRF Option 1 Vs Chiller Option:

Chiller Option: Yearly Energy Cost: $143,000

VRF Option 2 : Yearly Energy Cost: $83,800

Yearly Energy Cost Reduction

For VRF Option 2 Vs Chiller Option:

-57400$ = -40%

-59200$ = -42%

8 - MAINTENANCE AND SPARE PARTSChiller option

Yearly Maintenance and Spare part Cost

Item Qty Maintenance Operation cost /unit $ Total $

Chiller 2 6260 12520

Fresh Air Handling Units 2 680 1361

Chilled Water Pumps 6 410 2460

Fan Coil Units 139 40 5560

Treatment for Water / Chemicals 1 3000 3000

Spare parts - Inclusive

24901

VRF option

Yearly Maintenance and Spare part Cost

Item Qty Maintenance Operation cost /unit $ Total $

Indoor Units 152 40 6080

Outdoor Units 24 270 6480

Dx Fresh Air Handling Units 2 600 1200

Spare parts - Inclusive

13760

8 - MAINTENANCE AND SPARE PARTS

Reduction in maintenance and spare part yearly Cost of VRF options vs Chiller Option :

$ 24,901 $ 13,760-45%

9 - LIFE CYCLE COST

LCC-P = IC + ESPWF (COST energy + COST maintenance)

Where:

ESPWF = (1+d)n – 1

d(1+d)n

n= lifetime in years and d=discount rate in percent/100

Application: d = 0.08%, n=20 years, ESPWF=9.8

LCC -P Life-cycle cost Present value

IC Initial cost of alternative

ESPWF Equal series present worth factor

COST energy Yearly energy cost saving

COST maintenance Yearly maintenance cost reduction

9 - LIFE CYCLE COST

VRF Option 1 Life Cycle Cost is lower than Chillers by:

Air Cooled chiller VRF option 1

Initial Cost $1,109,609 $1,519,000

Yearly Energy Cost $143,000 $85,600

Maintenance And Spare

Parts Cost$24,901 $13,760

LCC :Present Value $2,758,086 $2,494,531

-264,000$ = -10%

9 - LIFE CYCLE COSTAir Cooled chiller VRF option 2

Initial Cost $1,109,609 $1,437,878

Yearly Energy Cost $143,000 $83,800

Maintenance And Spare

Parts Cost$24,901 $13,760

LCC :Present Value $2,758,086 $2,395,736

-362,000$ = -13%VRF Option 2 Life Cycle Cost is lower than Chillers by:

10 - ANALYSIS

A. Technical criteria

B. Financial criteria

C. Maintenance management criteria

10.A - TECHNICAL ANALYSISTechnical Considerations Air Cooled Chilled Water VRF System

System / Partial Load Response Low, due to Primary and secondary heat exchange

circuits.

High, due to Direct expansion

Outdoor Plant Requirement 2 Chillers fit on roof.

Area needed=140 m2

Minimum area for one chiller is 75m2.

* Covered Pump room area needed=50m2

Option 1:

24 outdoor units on roof.

Area needed=260 m2

Option 2:

2 outdoor units in each typical floor.

Area needed is 11m2 per floor.

Minimum Area per one OU-30Hp is 6.5m2, more Flexibility to fit

the outdoor units

No need

Fresh Air and Exhaust System Fresh air handling unit Can be connected to same

chiller.

Requires separate DX treated fresh air system.

Distribution System 1 shaft: 1x0.5m2 Option 1:1 shaft: 1.6x1m2

Option 2: No need

10.A - TECHNICAL ANALYSIS (CONT’D)Technical Considerations Air Cooled Chilled Water VRF System

* Acoustical and vibration treatment Acoustical and Vibration system is needed No need (or minimal)

Water treatment System Needed No need

Water Leakage High risk of damage on finishing materials No damage

Refrigerant leakage No limitations Refrigerant concentration to follow Ashrae limitations.

*Hydronic balancing Complicated and needs advanced labor skills No need

Air flow Set point for Indoor units Three speed fan (FCU)

No optimization since working point is not easily

met.

Wide range of fan air speed with multi setting of static

pressure to meet the required air flow leading to low

wattage and low noise level

10.A - TECHNICAL ANALYSIS (CONT’D)Technical Considerations Air Cooled Chilled Water VRF System

*Metering System for Rental areas and

shops in GF.

Required the addition of complete metering

system including but not limited to energy

meters, sensors, cabling, software and space for

installation.

Need Power meter connection to the Controller. Power

Design System Greater Responsibilities Easy design system

* Electrical Power, Cable and

Distribution system.

630kw For Chillers & Pumps Option1: 560Kw For OU

Relatively Same impact.

Option2: 44Kw Per floor

Major reduction in cable section/ length and electrical

Distribution system

*Items not considered in installation cost but will lead to additional Cost reduction

10.B - FINANCIAL ANALYSIS

Financial Considerations Air Cooled Chilled Water

System

VRF System Option 1 VRF System Option 2

Air Conditioning System Capital Cost

per Cooled Area, $/m2165 226 213

Yearly HVAC Running Cost per TR 433 259 254

Yearly HVAC Maintenance Cost per

TR75 42 42

*Residential Tower in Dubai: Average Construction cost is around 2000-2200 $ /m2 depending on building

height and standard.

10.C - MAINTENANCE MANAGEMENT

Operation Points Air Cooled Chilled Water Plant VRF System

Maintenance of outdoor units 2 chillers, 6 pumps, water treatment system to be

maintained

24 outdoor units need to be maintained

Maintenance and monitoring of Indoor units From each AHU/FCU One single point (outdoor unit) to monitor

related indoor units

Life system 20 years 20 years

Spare Parts More components to go wrong: chiller moving

parts, Control valves, sensors…

Less spare parts are needed

Control system Complex system Very simple

Calibration of Metering system for rental areas Energy meters need regular calibration Electronic type (PPD), no need for

calibration.

Maintenance for pipes insulation Highly needed to avoid pipes condensation minimal

Thank you Please contact CEDRO at:

T/F: +961-1-981944

E: info@cedro-undp.org

www.cedro-undp.org

Beirut, Maarad Street,

Building 287B, 1st floor

cedroundp cedro_undp CEDROproject cedroproject.wordpress.com