The HVAC chillers market has been growing, despite competition from other cooling technologies.

Technavio’s market research analyst predicts the global heating, ventilation, and air conditioning (HVAC) chillers market to grow steadily at a CAGR of around 3% by 2021. One of the primary drivers for this market is the growing demand for district cooling.

District cooling is replacing the traditional air cooling methods because of increased advantages like energy-saving, low environmental damage, and reduced maintenance needs. Furthermore, the increasing tourism market in nations of MEA and Asia has enhanced the construction of hotels and public infrastructure, which make extensive use of district cooling. HVAC chillers are one of the major facilities of district cooling.

Giving some numbers to this is Hakan Akman, product sales manager air conditioning, Systemair Middle East, who says that the market size of chillers in the Middle East is approximately $800m. He says: “Most of the clients are looking for energy efficient, reliable, eco-friendly, low sound and short term return of investment for the any equipment that they purchase.

"As a chiller is the heart and the biggest energy consumption unit of the whole HVAC system, customers are diligently checking all the aspects of the procurement and they analyse the total cost of ownership for 10 years. The lifetime cost of an air-cooled chiller is equal approximately to twenty times of its initial cost.

Therefore, the client should consider all parameters such as COP (Coefficient of Performance) and NPLV (Nominal Part Load Value) and choose the best solution for the load profile. Energy efficiency, footprint, noise, corrosive resistance are all factors to be considered in selecting the right solution for specific requirements.”

Water-cooled vs. air-cooled

Akman going more into the details says that air-cooled chillers have a greater volume of sales than water-cooled chillers as a result of greater requirement for smaller capacity units. However, in total cost, water-cooled chillers provide greater sales value.

He explains: “Even when an analysis is being made at design stage for a project the choice of feasibility of a system application can have different results depending on the project requirements. When you compare the COP or NPLV of the chillers only, the water-cooled units are obviously much more efficient. Additionally, there are different types of compressors used in both product ranges depending on the cooling capacity.

Hence, the efficiency of the chillers can show variation because of compressor types such as scroll, screw and centrifugal. However, the best practice should be comparing the system efficiency instead of chillers’ efficiency. The client should consider the compressor energy cost, make up water costs, sewer charges, chemical costs, cooling tower process pump, cooling tower pump and fan, air-cooled condenser fans and the required mechanical and civil works for both systems.

“According to our experience, water cooled system is more feasible if the total cooling capacity in the project exceeds 5MW. In some cases, the air-cooled chiller can be selected if there is not enough water source in the project location.

Chiller performance

One of the best method of evaluating the performance of chiller plants, according to Akman is that after all the design calculations about which system is more feasible and what is the estimate of the payback time of the investment, there should be a chiller plant control system to utilise the chillers in the most efficient area depending on the system demand. “There are several types of system configurations such as constant and variable primary flow, serial and parallel chiller arrangements and control methods. The best method can be defined on a case-by-case basis,” Akman concludes.