Cooling-system selection affects a tower’s plant space, maintenance access and operating costs throughout its life. For a Dubai high-rise, the decision requires an assessment of how cooling demand varies between floors and how equipment will perform under the project’s design conditions.
Consultants working with HVAC equipment manufacturers should compare complete system arrangements, including ventilation and controls, before finalizing the specification.
Establish how cooling will be distributed
A chilled-water system circulates water between the chiller and cooling coils in air handling or fan coil units. Central plant controls can sequence multiple chillers as building demand changes. This arrangement supports a shared cooling infrastructure serving numerous zones.
VRF distributes refrigerant to indoor units and adjusts its flow to meet individual zone requirements. Its zoning flexibility can suit buildings where occupied areas have different schedules. The assessment should establish which rooms share each refrigerant circuit and how those groupings match tenant boundaries and operating hours.
Check vertical distribution constraints early
For VRF, allowable pipe lengths and elevation differences are specific to the selected system. Long refrigerant routes can affect available capacity, making outdoor-unit locations and riser arrangements part of equipment selection. Capacity should be checked using the actual pipe layout and outdoor design temperature.
Chilled-water distribution introduces a different constraint. Water-column height creates static pressure that can exceed equipment ratings. Plate heat exchangers can divide a tall building into separate pressure zones, protecting connected components. Their temperature losses must be included when selecting the cooling equipment.
Include ventilation and refrigerant safety
VRF indoor units require a coordinated ventilation arrangement to provide outdoor air and manage humidity. This adds equipment, ductwork and energy consumption to the project comparison.
Refrigerant safety also influences circuit design. The connected charge must be assessed against the occupied spaces served, particularly smaller rooms. Depending on the applicable requirements, the design may need smaller circuits or other protective measures. These checks should precede final equipment grouping.
Compare annual operation and maintenance
A meaningful cost assessment includes installation, annual energy use and maintenance. For chilled-water systems, calculations should include pumps and terminal fans, plus cooling-tower operation where applicable. Water-cooled plants also require tower-water treatment and associated maintenance.
Air-cooled chillers eliminate the cooling tower, changing both space requirements and maintenance obligations. Chiller selection should therefore identify the proposed heat-rejection method before comparing costs with VRF. Annual modelling should use the building’s load profile and relevant utility costs.
Trosten’s equipment for building cooling and ventilation
Trosten Industries is among the UAE’s HVAC equipment manufacturers, producing air handling units, fresh air handling and heat recovery units, fan coil units and ventilation equipment. For high-rise projects, this range provides air-side equipment that can be selected around the building’s cooling duty, outdoor-air requirements and available installation space.