The cool approach
While ensuring guest comfort is priority, hotels are responsibly looking at the efficiency and energy consumption in HVAC systems – By Rashmi Naicker
HVAC system is critical to the comfortable operation of most buildings, be it commercial or hospitality, and is responsible for up to 40 per cent of the building’s energy consumption. However, unlike a commercial building, due to a hotel’s round-the-clock operation, downtime, is something that can never be afforded in this vertical. Hence, HVAC in hospitality, goes beyond good housekeeping and other operations; it needs to be detailed right down to intelligent system design, use of the right equipment, maintenance practices, and training support. Accordingly, the aim of any chief engineer must be to achieve improved guest comfort, reduce energy and operating costs, and demonstrate commitment to climate protection at the property.
Efficiency remains a top priority in the design of HVAC systems as utility costs continue to rise. As Rajesh Gandhi, executive director, sales and marketing, Cristopia Energy Systems (I) Pvt Ltd, rightly puts it, “A comfortable environment and welcoming ambience is critical for a hotel’s success, where the main focus is to make profit. The basic objective of designing an HVAC system is to render complete efficiency at optimised costs, while achieving contended guest experience and providing a comfortabble work environment for employees.”
Daikin, as a global market leader, maintains that hoteliers should look out for inverter-based products that are energy efficient in addition to offering ease of operation, smarter controls and intelligent features. “Consumers are beginning to recognise the need for an air-conditioning solution rather than a product only approach coupled with good after-sales service. More and more establishments are beginning to recognise the benefits of the higher star rating and inverter products to control long-term costs,” says Kanwal Jeet Jawa, MD, Daikin India.
More than 60% of new projects in the industry are being planned in tier-II and III cities, where energy is hugely erratic for extended hours each day, thus forcing hotel operations to use the much more expensive DG/alternate supplies, rather than the grid supply. Thus, all attention on the efficiency front particularly focuses on the chiller plants. More than 35% of the power required to run any building is consumed in this one unit equipment.
Another area, where efficiency can be monitored, is the heat pump. Pumps in an air-conditioning water system must operate, regardless of whether the system is cooling a building in summer or heating it in winter. Heat pumps consume about one-third of the energy used by a traditional boiler, yet, as compared to other pumps, they can be seen to consume significant amounts of energy since they operate all year round. This offers scope for energy efficiencies in the form or VPF or Variable Primary Flow pumps. A VPF system can reduce the power consumption of air-conditioning pumps and offers other benefits, including lower initial investment, reduction in the plant area required, simple control systems enhanced system stability and reduction in operating costs of three to eight per cent.
Addressing the variables
Rather than using one solution across different hotels, suppliers realise that the geography of markets, such as India, requires multiple answers. Variable systems are therefore the way forward. And although the use of Variable Refrigerant Systems (VRVs) have been in vogue in India for the last six or eight years, the trend has only recently begun to find widespread adoption, in spite of the huge power savings and efficiencies it offers. LG’s corrosion resistant Multi V IV, the company’s latest variable refrigerant flow unit (VRF) integrates sophisticated new technologies which effectively minimise energy loss under partial load conditions. Meanwhile, the Ocean Black Fin Heat Exchanger’s dual layered and double-sided coating shields the Multi V IV from corrosives like salt, sand and other elements brought in by strong sea winds, and even industrial pollution, immensely improving the durability of the system.
Experts say the best way to start is with building automation systems — also called intelligent building management systems. These building automation systems are increasingly being integrated with HVAC or chiller plant manager software to maximise the efficiency of chillers and the cooling tower. One of the earliest systems on this front is the Intelligent Building Management System (IBMS), reportedly pioneered by Johnson Controls with its Metasys product. It ensures that all a hotel’s systems — comfort controls, lighting, fire safety, security and equipment — operate together in harmony. Metasys coordinates and organises all the information logically, then delivers it where and when it is needed; thereby automatically controlling all the different systems in the hotel, even without anyone on duty.
One of the major problems in India, with its legacy properties, is the retrofitting of hotels to meet modern environmental and comfort requirements. “It is a good strategy for the chief engineers to review their operating cost and analyse the energy consumption of existing equipments their capacity utilisation, maintenance cost etc. Based on payback period analysis, hotels can plan for retrofitting of equipment like chillers, pumps, hot water and control systems etc.,”says Cristopia Energy Systems’ Rajesh Gandhi.
- initiating investment-grade audits of resource consuming systems
- analysing and benchmarking of the facilities’ energy usage and equipment efficiency
- using a benchmark to direct effective solutions and establish best practices
- prioritising energy- and cost-saving projects based on key performance indicators
- and, the installation of equipment and implementing the processes that are needed to meet core business objectives.
Retrofitting involves the following:
Besides incremental changes, retrofitting implies overall change of the redundant technology with contemporary and energy-efficient systems that rate highly on green buildings’ rating scale and are compliant with emission norms. Thus, retrofitting cannot be seen in isolation with respect to HVAC cost or electrical retrofitting, because it is generally accompanied by major changes in the interiors and public areas as well.
The benefits of retrofitting include the modernisation of all resource-consuming systems, while increasing the reliability of resource-consuming systems, increasing the value of the facility, delivering healthier, more productive workspaces, reducing the impact that facilities have on the environment, maximising efficiency by considering the inter-relationship of people, processes and technology, and, most importantly, reducing energy costs.