According to a market report research, the Indian HVAC market is expected to reach USD 5.9 billion by 2024, progressing at a CAGR of 7 per cent during the forecast period (2019-2024) against the backdrop of surging infrastructure spending in India.
One of the key trends in the Indian HVAC market is the adoption of energy-efficient HVAC systems. As a result, energy efficiency in HVAC has gained prominence as it enables 40-50 per cent of energy reduction in energy consumption in any building or infrastructure to be it commercial or residential. So, an HVAC system must operate as efficiently as possible to reduce the carbon footprint and depletion of natural resources. This reduces greenhouse gas emission by lowering the overall demand for electricity. While relating efficiency of HVACR systems with its performance, Vimal Chavda, Manager – HVACR, Testo India says, “An efficient system means improved Indoor Air Quality (IAQ), environmental comfort and optimised power utilisation.”
“A more efficient HVAC system will use less electricity to cool a house or building, and will also use less electricity to generate heat. Less power consumption means less operating costs and better environmental protection,” informs Daniel Chen, CAREL – APAC Marketing Manager (HVAC).
Enhancing Efficiency
It is pertinent to reduce energy consumption and increase the energy efficiency of an HVAC system while delivering a comfortable environment. The efficiency of an HVAC system significantly depends on its installation, maintenance and finally use of the system.
Chavda says, “The installation of HVAC system is very precise so that air and temperature regulation in the building is uniform and of the highest degree.” While talking about maintenance, he elaborates, “Maintenance includes regular inspections of the appliances along with the auxiliary equipment such as ducts and air filters. Proper cleaning, energy audits and replacement of non-performing components becomes a mandatory process. Thermal inspections can also be carried out to ensure proper insulation and avoid leakages in the buildings.”
The utilisation of HVAC systems becomes vital in maintaining efficiency. and promotes the building managers need to take proactive measures to decrease the energy consumption. Any office building lacking proper ventilation and temperature regulation systems can lead to decreased fresh air levels. Further, an excess number of people working in the office results in excess CO2 which can be a factor of air contamination, humidity and moisture levels along with the presence of dust particles in the surrounding that can degrade the air quality in the office premises. All these factors can consequently lead to overloading and over usage of the HVAC systems which can upset the overall efficiency. “There is a need to have efficient Building Management System (BMS) and responsible usage of the systems,” states Chavda. Installation of smart control software can bring efficiency in BMS, thus, leading to optimum operating conditions for the entire HVAC system.
Elaborating on this, Chen informs, “A smart controller can manage the speed, capacity or running time of HVAC system components such as fans, coolers or compressor motors and can also control the entire system according to the specific situation, to deliver the appropriate amount of heating or cooling.” He further adds that accurate and reliable measurements enable efficient HVAC operation. When troubleshooting more complex HVAC applications, it is useful to have sophisticated electronic control and protection systems that can interpret alerts and provide diagnostic information.
Optimal selection of the system helps to enhance the energy efficiency of an HVAC system as with the proper selection the user can control heating or cooling requirements as per his or her needs that helps to reduce overall energy consumption. Emphasising on the selection of the system for elevating efficiency, Chen says, “Select the HVAC unit that is right for the system based on the temperature needed throughout the year. Make sure that the system/unit works at its optimal operating point.”
Energy consumption of the HVAC system also depends on the cooling load that can be reduced by insulating the cooled space and minimising the use of appliances and lighting. These can help to reduce the cooling load.
Energy Efficiency Ratio
According to Chavda from Testo India, a simple method of analysing the energy efficiency is called Energy Efficiency Ratio (EER) which is the ratio of the cooling output divided by electricity usage in kilowatt-hours. The higher the number, the more HVAC energy efficiency it has.
Chen further lists out the following methods used to measure system efficiency.
Coefficient of Performance (COP): It refers to the ratio of useful heating or cooling provided to the work required. A higher COP means lower operating costs.
Energy Efficiency Ratio (EER): It is the ratio of output cooling energy in BTU/hr to input power in watts at a given operating point. COP is a more general measure of efficiency, and is unit-less, while EER has a unit of measure (BTU/kWh).
Seasonal Energy Efficiency Ratio (SEER):
It is also the COP (or EER) expressed in BTU/hr/W, but it is not evaluated in a single operating condition, rather it represents the expected overall performance based on the weather in a typical year at a given location.
Green Refrigerants
Moreover, the use of eco-friendly refrigerants also plays a key role in the reduction of energy consumption in HVAC system in buildings. The choice of the refrigerant has a direct impact on the depletion of ozone and also on global warming. Hence, it is imperative to use eco-friendly refrigerants such as R-134a which has zero ozone depletion potential and lower global warming potential. Chen from CAREL suggests, “Effects of traditional refrigerants on the environment and their banning in some geographical areas have made it fundamental for CAREL to use natural refrigerants with a low environmental impact, such as propane (R290), carbon dioxide (R744) and ammonia (R717), at times in tandem with variable-speed compressor technologies.”
Advancements in Technology
Advancements in HVAC technology like the introduction of DC technology and VSD (Variable Speed Drives) has brought a tectonic shift in the HVAC market. VSD technology can be implemented in fans, electric motors and other components to elevate energy efficiency in the buildings. “To use the example of variable-speed compressors as these do not always operate at maximum rated capacity, their energy consumption is considerably lower. Technological progress makes it possible to improve efficiency and reduce waste. Variable-speed units can operate at different capacities according to the required load, while a fixed-speed compressor can only be on or off. That makes variable-speed air conditioners more economical to run,” suggests Chen from CAREL.
Chiller Plant Energy Performance
Johnson Controls drives innovation and employs the latest technology and design to enhance HVAC system efficiency. These innovations include a variable speed drive in all the moving components of a plant room. “Coupled with advanced control strategies, this has greatly improved plant room efficiency,” observes Seemant Sharma, Director, Product and Distribution, Chillers, Asia at Johnson Controls.
Elaborating on chiller efficiency, Sharma explains, “Typically, the efficiency level achievable in a chilled water plant room that uses high-efficiency chillers with a conventional system design is close to 0.60 KW/TR for mild weather and 0.65KW/TR for a tropical coastal climate.” He further adds that to drive efficiency, designers have traditionally focused on using more and more efficient chillers, pumps, and cooling towers. But with rising energy costs and increasingly demanding Minimum Energy Performance (MEP) and green building standards, we need to look at more unconventional ways of achieving a breakthrough in efficiency levels.
A chilled water plant’s energy consumption depends on the work done by the compressor and pump. Sharma states that reducing work done reduces energy consumption. For a building in a tropical climate, with little or no respite from high wet bulb temperature, a plant room efficiency level of 0.55KW/TR seems out of reach because an efficient chiller alone would consume more power than that. He adds, “But we can go back to the basics and look at the building load. Building load has two components: sensible and latent load. We can reduce power consumption substantially with higher chilled water temperature to address the sensible load and lower chilled water temperature to address the latent load.”
To further optimise efficiency, Sharma suggests the following measures:
- Ensure a higher delta T in the chilled water system to reduce pump energy consumption
- Arrange the chillers in the series counter system to reduce compressor head
- Select a cooling tower with the lowest possible approach Using this strategy, Johnson Controls achieved 0.53KW/TR plant room efficiency at a site in Singapore, exceeding the GreenMark Platinum requirement.
The site consistently consumes 15 per cent less energy than other green buildings and 30 per cent less than a good plant room in a tropical climate.
Initiatives are taken by the industry
Testo is one of the market leaders in testing and measuring instruments providing a wide range of instruments that assist in maintaining an efficient system in the building and also ensure the desired IAQ level. Testo primarily provides measuring instruments for all HVACR applications.
Vimal Chavda says, “The testo 160 wireless LAN data logger measures, monitors and documents temperature, humidity, light intensity, UV radiation and CO2 concentration in rooms, offices and malls – automatically and without interruption – hence all indoor climate monitoring parameters are covered in one.”
Testo in its recent upgrade combines everything that makes the air velocity and IAQ measurement technology successful – intuitive operation, precise measurement values and an extensive probe range which can even work wirelessly via Bluetooth. The new testo 440 and testo 400 constitute of a compact handheld measuring instrument with user-friendly measurement menus and wireless probes – for the versatile and convenient measurement of all air conditioning and ventilation parameters. The probes are available for air velocity, temperature, humidity, degree of turbulence, CO2, CO and light intensity.
Daniel Chen from CAREL informs, “CAREL pays close attention to the source of power. The transition from traditional gas or fossil fuel heating systems to electric pump solutions will allow for better use of renewable sources.” He adds that the main new designs and innovations in HVACR technologies in recent years have led to:
- Optimisation of refrigeration systems and circuits,
- Introduction of variable-speed compressors using BLDC technology, facilitating greater efficiency in applications such as heat pumps,
- Specific devices for CO2 refrigerant applications, making the systems more efficient and extending the use of these applications to warmer geographical areas.
The ongoing development of these activities has also allowed CAREL to maintain its competitiveness in the global market for the introduction of new technologies in the HVAC sector.
In the humidification sector, CAREL focuses on adiabatic humidification, which allows the production of humidity using less energy compared to isothermal humidification. One related application is evaporative cooling, with more efficient temperature control, especially in air handling applications.
The new IoT division has allowed CAREL to concentrate on solutions that allow more advanced system optimisation solutions, along with the traditional monitoring of systems and alarm management. System operating data provides energy managers with additional information about system output. It also allows the assessment of any drops in performance, essential for implementing scheduled maintenance programs.
