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 total gross area of 300,000 m² and a conditioned area of 200,000 m², the building heavily relies on district cooling for its air-conditioning needs. However, over the years, inefficient HVAC performance led to excessive energy consumption, significantly increasing operational costs.
Despite its modern infrastructure, The Tower faced major challenges related to its low Delta-T, high cooling demand, and lack of real-time energy monitoring, leading to unnecessary penalties from the district cooling provider. The owners sought an energy-efficiency solution to address these issues while reducing operational expenses.
Problems
Several critical inefficiencies were identified within The Tower’s energy management systems:
Low Delta-T Performance: The Tower's Delta-T (temperature difference between supply and return chilled water) was measured at 3°C, significantly below the contractual 9°C required by the district cooling provider. This poor performance led to excessive chilled water flow, increasing district cooling charges, and incurring substantial financial penalties
Excessive Energy Costs: The Tower was spending 20 million AED annually on utility bills, a figure driven up by inefficient ventilation, outdated cooling systems, and poorly optimized HVAC operations
Oversized Cooling Contract: Upon reviewing the District Cooling Agreement, Ark Energy discovered that the contracted cooling load was significantly overestimated compared to the actual cooling demand. This resulted in unnecessary fixed capacity charges that increased the building’s costs
Lack of Digital Energy Monitoring: The tower lacked a real-time monitoring system to track and manage its energy performance. The absence of an advanced Energy Management Information System (EMIS) meant that inefficiencies went unnoticed and corrective actions were not data-driven
Tenant Energy Consumption Accountability: Without individual BTU submeters, tenants were not billed based on actual energy usage, leading to wasteful consumption behaviors and a lack of energy conservation incentives
Main Objective
Ark Energy was engaged to provide a comprehensive energy efficiency strategy to:
- Reduce overall energy costs by optimizing the building’s HVAC performance
- Improve Delta-T to minimize district cooling surcharges and optimize chilled water flow
- Right-size the district cooling contract to match the actual cooling demand
- Enhance digital energy monitoring through the deployment of an advanced Energy Management Information System (EMIS)
- Improve tenant accountability by implementing a BTU submetering system
Figure 01
The monthly energy cost & cost distribution within the tower over 12 months covering 2018 & 2019 (Values are in ,000 AED)
Figure 02
The percentage distribution of the energy cost in question
Approach
Ark Energy supported developing the energy efficiency project from tendering, auditing, and contracting to implementation. The project focused on:
- Managed a full energy efficiency project, from tendering and auditing to contracting and implementation, achieving 1.2 million AED annual savings from retrofitting the HVAC system in the building, followed by 3rd party M&V audit.
- We conducted a reassessment of the building’s actual cooling demand, identified an overestimation in the declared load in the district cooling contract, and successfully negotiated a lower contracted load, resulting in 480,000 AED in annual savings
- As part of the Delta-T Rehabilitation Project, we partnered with an ESCO to implement corrective measures, including the installation of Pressure Independent Control Valves (PICVs), Heat Exchanger (HEX) maintenance and smart control upgrades, and BTU meter recommissioning and installation, which significantly improved Delta-T and resulted in 2.7 million AED in annual savings from reduced cooling surcharges
- We deployed ArkEMIS, our Energy Management Information System (EMIS), to monitor and optimize all energy efficiency initiatives, enabling real-time tracking of Delta-T performance and ECM effectiveness while providing digitalized Measurement & Verification (M&V) for all implemented projects
- We installed BTU submeters for individual tenant spaces, implemented consumption-based billing to raise tenant awareness and drive better energy usage behavior, and achieved improved system maintenance and efficiency
Figure 03Annual Energy Cost Savings (estimates, ‘000s of AED)
Results
The results that were generated from the project include the following:
- Total annual savings of 4.38 million AED, reducing overall energy expenses.
- Delta-T optimization led to a significant reduction in district cooling surcharges.
- The right-sized cooling contracts eliminated unnecessary capacity costs.
- ArkEMIS digital platform provided continuous monitoring, ensuring sustained performance improvements.
- Tenant-level energy tracking fostered better energy management and accountability.
- Improved standards of comfort