Doing more with less

As one of the critical investments, and assets, for any hotel, the optimal functioning of HVAC systems is essential for the property’s overall profitability. This has underlined the criticality of prime energy management.

Fortunately, there is greater understanding and acceptance for integrating intelligent in-room devices and technologies to reduce HVAC costs today, especially with newer constructions. After all, smart buildings use information and communication technologies (ICT) to enable automated building operations and control.

“They can enhance occupants’ comfort and productivity while using less energy than a conventional building. While conventional buildings have systems operating independently, smart buildings use ICT to connect building systems to optimise operations and whole-building performance,” Arun Khanna, Director of Engineering, Hyatt Regency Delhi, pointed out.

The energy consumption of a commercial building continuously varies based on several dynamic conditions. According to Rahul Prabhakar, Chief Engineer at ITC Grand Chola, the energy management framework is highly dependent on the quality data at the right time, which allows building managers to be flexible and agile in their approach to energy reduction.

“The integration of smart in-room devices and other technologies helps us generate big data. The facility energy manager can use the Smart Building analytics platform to monitor and measure various aspects of the building. It can also bring in various other data inputs to extrapolate anomalies, making correlations, and helping end-users gain knowledge to make smart operational decisions that will affect the bottom line,” he claimed.

Dilawar Rana, Chief Engineer of Crowne Plaza New Delhi Mayur Vihar Noida, added that energy-management technologies could reduce hotel energy consumption by 25% to 35% by automatically responding to guestroom occupancy patterns. It can adjust the thermostat to conserve energy for heating and cooling in unoccupied guestrooms, which, according to industry statistics, is about 50% of the time in most hotels.

“Smart thermostat including motion sensor (Temperature controller) can give real-time temperature and HVAC energy consumption. It can help to schedule HVAC set temperature as per weather forecast & forecast of occupancy,” he explained. This can provide access to the front desk and guests who can see the room temperature even before check-in.

Such technology is very effective for energy saving when business is inconsistent. Of course, there are several other ways to control energy consumption, such as the cooling tower interface with BMS the condenser pump interface with BMS and CPM. The use of on-grid solar power generation systems, installing smart heat pumps, and enhancement of wastewater treatment also can play a significant role in reducing energy consumption. 

SMART MOVES

Thermostats in the guestroom have become the de facto standard for temperature regulation as per guest preference. It also avoids the over or undercooling of the space, offering guest comfort, in addition to optimising energy usage.

Arvind Dhiman, Director of Engineering at The Leela Palace Bangalore, stated how energy saving devices (ESD) could also go a long way in energy conservation. He pointed out how keycard holders resume and disconnect energy supplies to all lighting and connected power sockets whenever the guest removes them from the ESD.

“This also controls FCU in guest rooms by switching onto default temperature set points and the guest set point when the room is occupied or vacant, including modulation of fan speed. This device is installed in all guest rooms at The Leela Palace Bangalore, and over the years, it has become a standard part of the entire hotel industry,” he asserted.

According to Rakesh Tripathi, VP-Commercial Air Conditioning Business at Voltas Ltd, remote operation and monitoring of the systems is an intelligent way of doing business, and it needs efficient HVAC management. Many energy management systems in the market are specifically designed to cater to the needs of the hotel industry. He ticked off the key features of these systems, starting with real-time tracking of room occupancy and adjusting system loads accordingly, e.g. a hotel key card.

He also added that the HVAC equipment could be integrated with the IoT-based Remote Monitoring System of the Chiller OEMs for constant performance monitoring. This includes optimising operating parameters predicting failures if timely corrective or remedial actions are not adopted. 

IoT can also be leveraged for Indoor Air Quality (IAQ) monitoring since it has become imperative to keep track of the air quality. “IoT based IAQ monitoring systems should be deployed in the common guest areas of the hotels which help in capturing data pertaining to CO2 content, volatile organic content (VOC), PM10 and PM2.5 levels, based on these real-time data we can take corrective actions for improving the HVAC systems by retrofitting MERV filters, UVGI devices to the centralised Air Handling Unit (AHU) system for these common guest areas for improved indoor AQI. Guests can even be apprised of these air quality parameters on a real-time basis with the help of a monitoring screen,” he suggested.

Tripathi also recommended that hotels deploy a chiller plant manager at the plant room level to schedule equipment operation, chilled water temperature set-point control, and real-time system monitoring. Another measure is adopting an Automated Monitoring System for inside temperature conditions in common guest areas.

WALKING THE TALK

Most hotels have already deployed intelligent technologies for energy optimisation and conservation. For instance, Grand Kakinada by GRT Hotels has integrated its BMS systems with mobiles. It allows the staff to operate in the public area airconditioning through their smartphones instantly, thus avoiding the time duration to reach the software to switch it on or off. This has reduced the need for sending personnel from the control desk who can be employed in other areas.

Ranjith Kumar S, Engineer at Grand Kakinada by GRT Hotels, added, “We have also installed VFD with a timer for the kitchen exhaust. Fresh air is controlled as per the required flow, and the timer is set for non-peak hours. This reduces the workload of the staff, who can concentrate on other preventive maintenance for smoother operations.”

The Leela Palace Bangalore also has a Chiller Plant management system (CPM), an advanced control solution recommended for chiller plant applications with multiple chillers. “It automatically operates, controls, and monitors the chillers, pumps and cooling tower, reducing unnecessary operation. This increases the energy efficiency of the building’s HVAC system, and the team, which is trained to use these platforms, can effectively get the productive output from the plant,” Dhiman stated.

ITC Grand Chola installed a programmable Chiller energy optimisation control, like the Hartmann loop, to increase the system’s efficiency by around 10%. “Demand-based control is a means of applying the Equal Marginal Performance Principle. Here, the operation of the all-variable speed chiller plant is optimised based on the actual demand for cooling is satisfied by managing the power (kW) demand of each piece of equipment,” Prabhakar elaborated.

The hotel also has an in-room iPad control system to enable guests to be a part of its energy management framework. Guests can customise room climate controls, operate all the connected appliances optimally, and prevent wastage of energy.

“Smart thermostats enhance energy savings by taking feedback from room occupancy loop to enhance the temperature by a few degrees when the room is empty,” Prabhakar added. “Systems often also have a built-in temperature-recovery feature that ensures the guest’s preferred temperature is restored quickly upon his or her return to the room.”

At Crowne Plaza New Delhi Mayur Vihar Noida CT fans continuously interface with the BMS, use of solar light and condensate water for hot water generation and online management platforms continuously. It collects data related to HVAC runtimes for each unique room and assigns them efficiency ratings.

“This rating is an indicator of how quickly a room can be heated or cooled back down to the guest’s preferred temperature. It also provides the engineering team with critical alerts when the HVAC equipment needs attention. Moreover, it uses STP treated water for cooling towers, flushing and irrigation and use of DO meter to analyse the actual requirement of air blowers’ capacity, which have collectively helped us significantly to reduce energy cost,” Rana clarified. 

Hyatt Regency Delhi, too, has adopted various technologies for energy management in HVAC. It has a BMS that controls and schedules equipment operations as per requirement. Moreover, variable speed drives are built into all HVAC devices like primary, secondary, condenser pumps and cooling towers.

Khanna added that these devices don’t operate independently but in coordination with each other, as per demand, through ICT to give further advantage in energy conservation. “While a traditional building automation system (BAS) relies on preset schedules and setpoints for building operations, automated system optimisation (ASO) relies on real-time feedback. ASO uses ICT to collect and analyse building systems’ operational and energy performance data and make anticipatory changes in operations based on external factors such as occupancy patterns, weather conditions, system temperature and pressure etc.,” he reaffirmed.

The hotel has installed an online automatic condenser tube cleaning system on the maintenance front. Here condenser tubes are kept clean, and the staff doesn’t wait for tubes to get dirty and take the equipment under maintenance for cleaning. “When the system is kept clean, its efficiency is always optimum with the added benefit of lower maintenance cost and downtime,” Khanna pointed out.

CHECKS AND BALANCES

Hotels can easily take advantage of intelligent occupancy controls available by controlling Rooms Fan coil unit through IoT sensors and linking same with hotels’ front office property management software. Hyatt Regency Delhi has a head start and uses the room key to control HVAC and other devices. According to Khanna, these initiatives have helped the hotel save 12% to 15% on its HVAC operation cost.

Grand Kakinada by GRT Hotels also installed a key card relay system for guest rooms, which is merged with the A/C thermostat. This makes the thermostat work in occupied and unoccupied mode. Explaining its working, Kumar stated that when the key card is removed, the A/C setting goes into unoccupied mode and switches to hotel setting mode, which is preset by the engineering team. This makes a considerable saving, and there is no regular monitoring required for the staff.

Hotels near coastal areas face a massive challenge with increased involvement of engineering and housekeeping to maintain the rooms. Hence, Grand Kakinada by GRT Hotels installed a dehumidifier in guest rooms to control the relative humidity.

“This has resolved issues like fungus growth or need for painting once a week,” Kumar happily claimed. “The installation of the dehumidifier has reduced our HVAC cost by 38%. The expenditure in R&M painting and furniture and fixtures upkeep has also gone down by 40%. Moreover, we installed sensors in all washrooms, which has also resulted in a whopping 50% cost saving.”

The Leela Palace Bangalore also uses occupancy sensors to reduce and regulate the room FCU when the guest has kept the key in the keycard slot and is physically not present in the room. “When this occupancy is not detected, the FCU can still go to the default set temperatures, thus saving the energy,” Dhiman claimed. “Our hotel has also invested in the VFD for all the HVAC installations which run on closed-loop circuits which derive savings depending on hotels fluctuating HVAC loads.”

Tripathi of Voltas stated that smart HVAC systems could provide qualitative data and information to the operators, maintenance staff and costing staff regarding the actual health of the system, the energy consumed and the costs incurred. This is the optimal method to achieve energy efficiency, save on operational costs and increase and maintain better system health.

“At Voltas, our endeavour has constantly been innovating and coming up with products that suit the needs of our customers. Our current focus is on energy efficiency through technology and green refrigerants. With our wide range of products including energy efficient VRF systems, Packaged ACs, Ducted systems and engineered products such as high-efficiency Chillers,” he proclaimed.

Rana recommended that hoteliers use occupancy to manage shades and drapes in guestrooms. This will assist in maintaining lower temperatures in unoccupied rooms and minimise the fading of soft goods within the guestroom.

Accurate occupancy detection, practical lighting and drape control and comfortable humidity management – hoteliers are thinking out of the box to manage their energy usage smartly while keeping guest comfort at the centre of it all.