Today’s HVAC systems provide thermal control and indoor comfort, besides conforming to health regulations
Customisation and energy economy are driving this year’s technology trends. Smart HVAC products increase room-by-room environmental control and regulate heating and cooling methods, allowing occupants and owners to manage their energy use, easily and efficiently.
HVAC systems help in maintaining air quality in residential and commercial establishments by adequate ventilation, filtration and thermal balance. The real estate sector has been influenced to improve its HVAC systems owing to stringent policies on eco-friendly norms, safety prerequisites, advances in technology, and the need for efficient use of energy.
THE ENVIRONMENT AND HVAC
The growth of the Indian real estate sector is one of the key demand drivers of the emergence of the HVAC market and reduction of carbon footprints. Senthil Thangam, senior general manager, Commercial Air Conditioning Division, Blue Star, states that these days most of the products are with equipped with environment-friendly refrigerants. “The new products developed and introduced in 2019 such as the next generation inverter-ducted, water-cooled VRFs are all with eco-friendly refrigerants. Blue Star has also launched the inverter split ACs with in-built air purification system, capable of maintaining PM2.5 as per the norms,” he explains. For large applications like VRF, Blue Star has specially designed treated fresh air units, which maintain the indoor air quality very efficiently.
A green HVAC system helps commercial, industrial and educational institutions, tech giants, government facilities, large corporations, small and medium-sized businesses, and residential customers to conserve important natural resources using the most efficient and environmentally-friendly technologies, which results in lower utility bills for their air conditioning and heating. While usually incurring some expenses initially, the improvement in the energy efficiency makes them more and more economical as time progresses.
Regarding the environment, Yozo Ito, director and business head, Living Environment Division, Mitsubishi Electric India, advises, “Air conditioners that use eco-friendly refrigerants are the best choice as environment-friendly systems. Mitsubishi Electric’s air conditioners, besides being eco-friendly, also have high energy efficiency and consume lesser amount of electricity – which is good for the environment. Moreover, they’re also very durable and can last for a very long time, thereby, reducing wastage.”
In terms of indoor air quality aspects, air conditioners come loaded with different types of filters that help in purifying the air and improving air quality. The filtration process is further optimised by using a fine particulate matter (PM2.5) filter to further better the quality of the air.
Devidas Kulkarni, head - regional solutions & services, Smart Infrastructure, Siemens India, explains that with increased awareness about air pollution, there is more focus on maintaining PM levels for better air quality. “PM sensors, well-integrated with air side systems and controls help in deciding the right solution to maintain it at a healthy level. The PM sensor, commonly called fine dust room sensor, is designed to measure and transmit indoor concentrations of PM2.5 and PM10. These aesthetically well-designed, wall-mounted sensors can connect directly to any controllers via voltage output or Modbus,” says Kulkarni.
FACTORS FOR HVAC INSTALLATION
The location of the building, availability of power, water etc., are considered when the decision to install the system is taken. Also, the type of building occupancy – residential, commercial, hospitality, health care, industrial, matters. “We also review the glazing requirement and select a thermally glazing system and identify the scope and areas requiring air conditioning,” says Brijesh Shaijal, principal architect, Design Art & Culture (DAC).
Besides all this, the study of temperatures, humidity, requirements of various spaces/ zones, is done. The air conditioning requirement for a building is determined by the ambient weather conditions. “Evaporative cooling could be looked at in areas with very dry weather for pre-cooling the entering air,” explains Shaijal.
Water cooled systems could be looked at for areas where fresh or treated water is available. Limitations on power availability may require water cooled/ hybrid systems to be installed. Depending on the movement of the sun and heat zones, sufficient shades need to be provided to reduce the heat load. Low thermal conductivity materials should be used for external walls and roof construction material.
Thangam adds, “Before installing the HVAC system, it is important to note the size of the application, location of site and constraints, type of application, building aesthetics, availability of budget/ resources, usage pattern of the system and interior layouts. Indian climatic conditions are tropical with much higher temperatures compared to other parts of the world.”
REDUCING ENERGY COSTS
All commercial and industrial equipment requires regular maintenance to operate at full efficiency. Some of the maintenance measures are to replace air filters regularly, clean and adjust dampers, as well as check and calibrate the thermostat regularly.
Ito explains that the latest technology advancements in the HVAC industry have made ACs more energy efficient. “For example, inverter technology-based compressors can run continuously, vary the speed during partial load requirement to match precisely the required room temperature, saving the energy required to run on full load,” he adds.
Smart controllers monitor the air conditioning system automatically by sensing the user’s cooling requirement. There are a number of automatic control features in Variable Refrigerant Flow systems that help in saving energy. For example, the energy saving assist function allows the AC to vary the temperature of the refrigerant according to the load, which promotes energy efficiency. The capacity assist mode, on the other hand, prevents drop in cooling capacity during operation at high outside air temperature. By using the rapid mode, faster cooling is achieved for the first 30 minutes after start-up, to quickly establish comfortable conditions, while the night mode reduces noise of the outdoor unit during night-time.
Thangam explains, “The shift from the old, conventional fixed capacity systems to the latest inverter technology can save more than 30% of the running cost. Besides, chillers with magnetic levitated technology are available, which offer substantial savings in large applications.”
The VRF systems are highly advanced, fully electronic-based and can have sophisticated automatic controllers. These controllers precisely regulate the capacity of the systems based on the internal load, offering huge savings to the customer.
Kulkarni believes, “It is not necessary that we always need to replace or make changes to obtain energy efficiency. Ironically, we do not have proper metering solutions implemented at most of the sites. What you wish to save, needs to be measured first! Current efficiency levels of systems are not known. Thus, extracting the best output from existing systems can be done by advanced auto controls of all components in an HVAC system.”
IMPROVED ENERGY EFFICIENCY
Manufacturers are always looking at new systems to improve energy efficiency in their products. The magnetic bearing centrifugal chiller, Aeroseal, Ecoflair and energy recovery ventilators are all important.
Every year, Blue Star introduces products with enhanced efficiency. “We were the first to introduce the VRF systems designed for Indian operating conditions at 43°C. These systems not only deliver the full capacity, but also work on high efficiency. The magnetic levitated chillers, which are oil-free offer part load efficiency of 0.29 KW/TR – these are the most efficient chillers in the country. The next generation inverter-ducted offers 30% more efficiency compared to regular conventional systems in the market,” informs Thangam.
Mitsubishi Electric has introduced Split – 5-star rated (GR/ GR-T) as well as Variable Refrigerant Flow – premium segment energy saving products to enhance the energy efficiency of their HVAC systems.
As for Siemens, the company looks at a holistic solution-based approach. Their flagship offering, Demand Flow – a proven and patented solution, primarily solves the challenges associated with chiller plants using an advanced customised algorithm, thereby providing energy savings in the 20% to 40% range.
The average life of any HVAC system is expected to be between 10 years to 15 years, depending on the usage and the maintenance of the system. The lifespan of an HVAC system varies based on type of equipment and systems. Chilled water plants have a higher lifespan than direct expansion type modular systems. However, the life of a system depends on how properly it is being maintained. Kulkarni believes, “The industry has moved from preventive to predictive maintenance. Data from connected equipment can diagnose in a timely manner the faults, while corrective measures can be taken well before any failure occurs. Thus, digitalisation is the way forward for effective maintenance of systems that facilitates a continuous process instead of a time-bound activity.”
Maintenance is a must at least once in three months. For machines which are not maintained, the efficiency can easily drop by 15%, if not more. “The cost of maintenance will be much lesser than the additional running cost that the customer may spend. Hence it is highly recommended to get the AC systems maintained by the manufacturer,” advises Thangam.
Senthil Thangam, senior general manager, Commercial Air Conditioning Division, Blue Star: We offer end-to-end solutions starting from design to after-sales service. Blue Star and its channel partners have trained engineers who are capable of offering Design and Build solutions.
Yozo Ito, director and business head, Living Environment Division, Mitsubishi Electric India: Yes, Mitsubishi Electric in India offers HVAC solutions for residences, clean room applications, medium commercial applications like show rooms, small offices, clinics etc. Furthermore, our central air conditioning applications can take care of the air conditioning needs of commercial buildings, high-rise residential buildings, office buildings, hotels, hospitals and educational institutions. All our applications come with the promise of providing fresh quality air.
Devidas Kulkarni, head - regional solutions & services, Smart Infrastructure, Siemens India: Yes. Siemens, over the years, has developed the domain expertise to provide a total solution package for HVAC. Siemens takes up turnkey projects as a one-stop solution for HVAC design and implementation for not only controls, but electro-mechanical retrofits as well. We believe and propagate a holistic approach to energy efficiency, covering all aspects of HVAC – right from design expertise to the selection of a suitable product range, Siemens helps its customer to overcome challenges associated with existing or new facilities.
When would you recommend upgrading the HVAC system(s) in a building/ complex?
Thangam: It depends on the age of the system, being aware of the technology being used, the performance, running and maintenance cost, and being in touch with regulatory changes.
Ito: Regular changes in climatic conditions are increasing the requirement of air conditioning and ventilation. With increasing ambient temperature, capacity of pre-installed systems will decrease. And, at a certain point, the existing HVAC equipment will not be able to match your requirement. Also, the same equipment will consume a higher amount of energy compared with initial years. Increase in consumption of electric energy to previous years is an indication of upgrading your air conditioners to the latest models with the latest technology. To upgrade the HVAC System, proper heat load estimation is required, and the HVAC professional should be able to figure the same. Due to rapid upgradation in technology, it is better to replace the air conditioner in a span of 7-10 years for better efficiency and comfort.
Kulkarni: The ideal time is when you have a decent payback for any upgrades. It is wiser to replace a relatively new, inefficient system with proper lifecycle analysis than to live with it for 8 to 10 years.
What role does weather/ location of a building play in determining what system to use?
Thangam: The Indian climatic conditions are tropical with much higher temperatures compared to other parts of the world. There are also other factors like urban heat effect that will further enhance the operating temperatures of the AC system by 4 to 5°C. There is a need to design a system which will work at high ambient zones in India. All Blue are deliver 100% capacity at 43°C. Our water-cooled ducted systems deliver full capacity in the high ambient zones and work on high efficiency platform. Customers need to understand the impact on efficiency due to global warming and urban heat effect before selecting the right system.
Ito: You must always consider the climactic conditions as well as your geographical location before choosing an HVAC system to get the most out of the air conditioner. For example, if you reside near a coastal area, you should opt for outdoor units which have anti-corrosive coating to prevent them from excess moisture and other corrosive agents in the air. If you want a system for an area that has low ambient temperatures (less than 0°C), you should employ the heat pump type system. However, if the area does not have very low ambient temperatures (not less than 10 °C), you can use cooling only type system. Also, water-cooled systems should not be used in high relative humidity zone (tropical regions).
Kulkarni: A country as geologically diverse as India needs the right approach while designing a system and selecting an equipment for specific locations and weather conditions. The major load on a system is on account of fresh air intake. Climatic conditions decide what type of fresh air treatment and controls are required.