Background Story

The Tower is an iconic 80-story mixed-use skyscraper comprising 25 commercial floors, 48 residential floors, and a retail/shopping mall. Since its opening in 2011, the building has served as a key business and residential hub, offering premium office spaces, luxury apartments, and high-end retail experiences.
With a gross area of 300,000 m² and a conditioned area of 200,000 m², the building relies heavily on district cooling. However, poor HVAC performance, coupled with a lack of real-time monitoring, had resulted in excessive energy consumption, operational inefficiencies, and district cooling penalties. Ark Energy was engaged to reverse this trend through a comprehensive energy efficiency strategy.
 

Problems

key challenges identified at The Tower included:
 

• Low Delta-T Performance: Supply-return temperature difference was 3°C—far below the contractual 9°C threshold—resulting in increased chilled water flow and financial penalties.
• High Energy Costs: Utility bills reached 20 million AED annually, largely driven by inefficient HVAC and ventilation systems.
• Oversized Cooling Contract: A review revealed the contracted district cooling capacity significantly exceeded actual demand, leading to inflated fixed charges.
• No Real-Time Energy Oversight: The absence of a digital energy monitoring platform made it difficult to detect inefficiencies and intervene promptly.
• Lack of Tenant Accountability: Without BTU submeters, tenants were not billed based on consumption, undermining energy-saving behaviors

Figure 01
The monthly energy cost & cost distribution within the tower over the span of 12 months covering 2018 & 2019 (Values are in ,000 AED)

Main Objective

Ark Energy was engaged to provide a comprehensive energy efficiency strategy to:
 

1. Reduce overall energy costs by optimizing the building’s HVAC performance
2. Improve Delta-T to minimize district cooling surcharges and optimize chilled water flow
3. Right-size the district cooling contract to match actual cooling demand
4. Enhance digital energy monitoring through the deployment of an advanced Energy Management Information System (EMIS)
5. Improve tenant accountability by implementing a BTU submetering system

Figure 02
The percentage distribution of the energy cost in question

Approach

As the client’s consultant, Ark Energy implemented the following measures to achieve the project’s main objectives and address specific sources of energy consumption:

1.Energy Efficiency Retrofit Project

Ark Energy, in partnership with an ESCO, implemented key Energy Conservation Measures (ECMs):
 

• Ventilation Optimization – Installation of VFDs on FAHUs for demand-based airflow regulation
• DX Unit Replacement – Swapping outdated DX units with high-efficiency models
• Chilled Water Pumping Optimization – VFDs on chilled water pumps to enable flow modulation

These interventions led to 1.2 million AED in annual savings by improving HVAC efficiency.

2. Thermal Load Assessment & Contract Optimization

A thorough thermal load reassessment, using live building data and simulation tools, revealed that the building’s cooling contract was significantly oversized. Ark Energy renegotiated the agreement, reducing unnecessary fixed charges and securing 480,000 AED in annual savings.

3. Delta-T Rehabilitation with Targeted Monitoring

To eliminate Delta-T penalties, Ark Energy launched a structured Delta-T improvement program:
 

• PICVs Installation – Pressure Independent Control Valves were deployed across all critical zones to control water flow and eliminate bypassing
• Priority-Based Tracking – After installation, the worst 10 performing areas were continuously tracked in ArkEMIS, enabling targeted intervention
• Web-Based Delta-T Analytics – A custom-built Delta-T management platform was introduced, giving visibility from main header level down to each tenant, including real-time Delta-T and flow readings

These actions helped improve Delta-T significantly and eliminated 2.7 million AED in annual surcharges.

Figure 03
PICVs monitoring by arkEMIS, recommendations are provided by the Energy Managers, Actions taken by FM team

Figure 04
Monitoring all zones across the ChW network in web based DTMA

4. Digital Energy Management with arkEMIS


The deployment of arkEMIS, Ark Energy’s cloud-based Energy Management Information System (EMIS), became the cornerstone of project success. Its contributions included:

• Real-time monitoring of Delta-T, energy usage, and ECM performance
• Continuous analytics that enabled proactive issue detection and optimization
• Automatic tracking of worst-performing areas and system alerts
• Monthly customized performance reports highlighting:

• Energy consumption and trends
• Summary of operational issues
• Penalty exposure
• Utility billing insights

This level of digital transparency not only sustained the performance improvements but also empowered the client with ongoing energy management capabilities.

Figure 05
Exec summary of Customized Report

5. Third-Party M&V Audit

Ark Energy validated all reported savings and ECM results through an independent M&V audit, reinforcing transparency and long-term reliability.


6. BTU Submetering for Tenant Accountability

To further drive efficiency, BTU submeters were installed for all tenant spaces, enabling usage-based billing and increasing tenant awareness. An engagement program was also launched to educate occupants on energy-saving practices.

Figure 06
Monitoring each apartment

Results
 

• Improved energy and water efficiency through data-driven decisions

• Increased cost savings and performance transparency

• Optimized operation and maintenance strategies

• Improved internal and external reporting

• Improved compliance with regulations and standards

• Increased portfolio-wide visibility and control

• Informed energy and sustainability planning

• Streamlined stakeholder communication

Figure 07

Annual Energy Cost Savings (estimates, ‘000s of AED)