Background Story
The client owns a commercial office building located in Downtown Dubai, comprising office spaces, meeting rooms, lounges, and retail areas. The total conditioned floor area of the building is 25,000 m², with 8,000 m² allocated for common areas such as hallways, elevators, and bathrooms. The building’s cooling system plays a crucial role in ensuring comfort for tenants and visitors while also minimizing energy consumption and operating costs.
Ark Energy was tasked with conducting a thorough cooling load assessment. The goal was to determine the difference between the signed cooling load and the actual cooling load, allowing the client to negotiate with the District Cooling Provider to potentially reduce the Declared Load and optimize cooling efficiency.
Problems
The primary challenge in this assessment was the variation in cooling demand across different areas of the building. For example, office spaces and meeting rooms experience fluctuating occupancy levels and varying operating hours. Additionally, the retail areas and common zones had different cooling requirements compared to offices. Despite these challenges, the cooling load assessment was completed successfully using the HAP Energy Model Software.
Main Objective
The main objective of this cooling load assessment was to compare the signed cooling load with the simulated cooling load generated through the HAP model. Ark Energy delivered precise thermal load estimates using site data, client documentation, and survey reports. These findings supported the client’s case for reducing the Declared Load with the District Cooling Provider.
Approach
Ark Energy used a structured and data-driven approach, considering the following factors:
Architectural and layout drawings of the building
Internal heat gains from office equipment, lighting, occupancy, and appliances
External environmental factors, such as ambient temperature and solar exposure
Worst-case scenario conditions, including:
- Occupancy fluctuations in office spaces and meeting rooms
- Operational hours for retail areas and lounges
- Lighting schedules and appliance usage patterns
Table 01
Overall plan conducted for the Thermal Cooling Load Assessment for this building
The actual cooling load of the building was found to be 7% lower than the signed load with the District Cooling Operator
Table 02
Deviations presented from the analysis emphasize the difference between the actual and signed cooling loads
Some of the findings from the analysis are as follows:
- Office spaces required 300 TR of cooling, which was 5% higher than the signed load of 285 TR, Meeting rooms and conference areas required 120 TR, which was 3% lower than the signed load of 125 TR. Retail areas and common zones required 150 TR, which was 10% lower than the signed load of 165 TR
- Retail areas and common zones required 150 TR, which was 10% lower than the signed load of 165 TR
- The total cooling tonnage required by the commercial building was calculated at 700 TR, which is 7% lower than the signed load with the District Cooling Operator
Figure 01
Actual Declared Load distribution assessment reveals that the landlord’s consumption is lower than the simulated Peak and Calibrated design conditions
Based on the analysis, a reduction in the Declared Load is recommended. Additionally, to improve the building's energy efficiency, the following measures should be considered:
- Energy efficiency upgrades, including improved insulation, better HVAC systems, and temperature controls for varying office and retail areas
- Low Delta-T rehabilitation to optimize cooling performance and minimize energy wastage
- Energy management digitalization to track and adjust energy usage in real-time for different zones in the building
Results
The results that were generated from the project include the following:
- An assessment of the declared load was provided
- Further insight into the further reduction