Chillers and cooling technologies align with environmental safety

Evolving trends and innovative cooling methods to focus on environment protection and to provide energy-efficient cooling via future chillers, along with advancing green and passive cooling technologies, are priority concerns of industry experts.

Chillers are refrigeration systems offering cooling facilities for commercial and industrial applications. Various cooling technologies exist, such as electronic and thermal, liquid and air, passive, evaporative and radiative. Researchers at MIT (Massachusetts Institute of Technology) have further advanced the technology to achieve passive cooling – a method that does not require electricity. The newfound opportunities are working towards innovative cooling technologies to provide cooling process solutions. India’s chiller market is driven by the food and beverage industry and the increasing trend toward green buildings. The demand for absorption chillers is increasing due to eco-friendly cooling equipment in end-use industries. Also, energy efficiency and a high level of cooling with minimum ecological impact drive the demand for chillers. However, single-screw inverter compressors are a good solution in data centres. The global chillers market is estimated to be USD 4.1 billion in 2021 and is projected to reach USD 4.8 billion by 2026. Further,rising temperatures due to global warming will likely drive the demand for cooling equipment. Moreover, there is an increased focus on environmental protection from the emission of gases during the cooling process.In the backdrop of environmental concerns and the pollution crisis in Indian states, the cooling technologies need to be revamped and reworked especially concerning large and big spaces.

Evolving trends for cooling technologies 

“Both energy and the environment are intertwined. The key point is refrigerants, especially regarding HVAC and chillers”, says Mr. Achyut R Kulkarni, Applied and Unitary Stream Leader for India and SAARC market, Trane Technologies. That is extremely important. And today, we already have a clear mandate, even from the Government of India, because we have already ratified the Kigali agreement, and COP 27 is also looking at how important it is to shift from HFC to HFObased refrigerants. He points out most companies have already done that, and based on the changes, and we have a notion that in our industry, things will be much better for space cooling in the future in terms of the environment.

Technology to use environment friendly refrigerants 

Large space cooling is generally associated with commercial and large building applications. Typically, consultants, large architects, and contractors seek to design centrifugal and large screw chillers for all large applications. Elucidating the point, Ms. Kshama Jain, Managing Director, Kehems Technologies, states, “We should look for better energy-efficient chillers with environmentally friendly refrigerants so that they do not have a negative impact on the environment. And when we talk about large space cooling, we usually mean a full range of chillers.” The point is that water cooled centrifugal or water-cooled screw chillers are used for large space cooling.

The issue of global warming is providing many opportunities for the cooling and heating industry. There are many low impact refrigerants like CO2, hydrocarbon, methyl chloride or ammonia for cooling systems. Nature can help with that. Mr. Ashish Rakheja, Managing Partner, AEON Consultants, firmly believes in using passive cooling technology first, followed by active cooling technology. He pointed out, “Every city in India has six months of pleasant weather. We tend to close ourselves so tightly in our buildings that we do not realise whether we need air conditioning or cooling, but we end up doing so. And then, we will think about cooling for the rest of the year.” 

Elaborating further, Mr. Ashish says other cooling technologies, such as compressor-based refrigeration, are coming in because compressor-based refrigeration presents energy challenges. That can be investigated because not all climates require compressor based cooling all the time. We are using a compressor, where HFC refrigerants are now used, ensuring that global warming is avoided. The HCFC phase-down has already begun, and HFO is on its way. “Natural refrigerants must be visible, and work in that direction is being done. Natural refrigerants will take some time to enter the commercial cooling market. However, the future belongs to HFO.”

Design changes for green cooling Like the global cooling market, refrigerant-based cooling technologies have a more significant share of vapour compression systems than vapour absorption systems due to commercial benefits. As compared to vapour compression chillers that use compressors, vapour absorption chillers use the collection of waste heat from other processes or equipment to drive a process that allows water to be chilled and distributed for cooling. The current concept is going green. The design changes must be included for chiller plant operation to increase system efficiency for green cooling. Mr. Vijay Raina, Assistant National Sales Manager for the Adsorption Chiller division, Bry-Air, explains, “In various applications, very little energy and water can be used as a refrigerant, but the commercial challenge lies in the fact that hot water is not available everywhere. However, a technology to provide 100 percent green and 100 percent environmental safety is needed for industrial applications. In industrial applications, we typically get hot water at low temperatures ranging from 60 to 80 degrees Celsius.” The complementary technology of absorption chillers requires a high-grade heat source of around 80 degrees. Previously, no technology was available to provide green eco-friendly technology.

For industrial customers and commercial buildings, the hot water source has gone solar thermal. The architect needs to carve out space while designing and adopting solar cooling for commercial applications. “In some cases, 100 percent power can rely on a fuel base such as natural gas, which emits less carbon and allows buildings to be zero-carbon.” However, that is dependent on commercial fuel prices. So, this technology can be implemented to save the environment and make it a 100 percent green technology. As driving energy, the hot water can use adsorbent silica gel that can withstand temperatures up to 100 degrees. As a result, solid silica gel can be used. It can produce 200 degrees of high-pressure steam. This silica gel technology can defeat basic efficiency in plants. Hence, it is a better option to implement for commercial solar applications and use low grade waste heat for industrial applications.

Opportunities for large-space cooling 

Exploring e-commerce business growth, Mr. Mukesh Aggarwal, General Secretary, Federation of Cold Storage Association of India, opines, “The commodities require almost four temperature zones, including frozen, chilled, low 15- 16 degree refrigeration, and dry zone. Typically, these four zones are required, and the challenge we face as consumers is that large land parcels are not available in developed areas.” These logistics parts must be developed on the city’s outskirts or in remote locations 10-12 kilometres outside the city. There is an impending need for a 10-20 acre warehouse facility, and within that shared warehouse, one must develop frozen cold storage, chilled cold storage, and so on.    

These days, the ambient air temperature can reach 49 degrees. Having an air-cooled refrigeration system is a must. The amount of refrigerant tonnage required increases dramatically during 40-50 days of summer, and the requirement is very low during the rest of the year. Moreover, the CAPEX for refrigeration is quite high to meet the situation in those 40-50 days. And if you go with a water-based water-cooled or refrigeration system, the quality of water available in those areas could be better. And at that level, whatever compressors, water, or cooled condensing systems are being used may become choked. So, if you balance it with the waterbed system, you have a problem with high TDS, as a high level of TDS in water can lead to several health problems. And balancing it with the airways cooled system, a problem with high ambient occurs. These are some of the industry challenges.

Evaluating cooling technologies for large spaces 

In view of the increase in industrialisation and urbanisation, innovative cooling technologies for large spaces have to be researched, considering environmental sustainability. “We appear to have abandoned the traditional way of doing designs or the knowledge that we had either forgotten or chosen to forget”, says Mr. Ashish. “We started making buildings that look the same in all climatic zones.” There are now codes and standards being discussed that incorporate the concept of climate consideration. So, in the future, we must be mindful of the climate. Regarding passive heating and cooling, he remarks, there is a concept known as adaptive thermal comfort. And a human body can withstand a temperature of 50 degrees. 

Carbon neutrality is a reality; we can do better than the 22 degrees we prescribe as we move towards a low-carbon world. We intend to become a carbon-neutral nation. It could happen in 2050, 2060, or 2070. Our Prime Minister says it will happen, and when it does, it is a matter of time. It can be achieved cost-effectively if we keep working with today’s technologies. India will be consuming more than 50 percent of global energy for space cooling by 2050. The option is to embrace nature and adapt to it. This will help reduce operating costs and carbon emissions reduction resultantly.

Conclusively, high expectations are there to see passive cooling concepts come in because that will help turn the table faster. Passive cooling is a building design approach focusing on heat gain control and heat dissipation to improve indoor thermal comfort with low or no energy consumption. Thus, the passive cooling approach prevents heat from entering the interior or removes heat from the building. And we do have passive cooling technologies available. Passive cooling uses free, renewable sources of energy such as the sun and wind to provide cooling and ventilation needs. This additionally removes the need to use mechanical cooling. This may not suit certain places or ambient temperatures, but that is something that will drive the cooling technologies market. It is just a positive approach and phenomenon for the future.