It’s now a known and established fact that HVAC is one of the most crucial element in a commercial building. Today, it’s not just about how efficient they are but also how easy they are to maintain through their lifecycle — from a technical and operational standpoint. Hence, it is imperative to ensure that the building is equipped with the right system.
Many of the higher efficient HVAC systems may be capital intensive but they deliver a promising ROI across all boards. Hence, it’s imperative to check and maintain the system regularly, says Captain Sanjay Saket, head – Administration, Bajaj Allianz General Insurance Company Limited. He adds, “I believe in cost optimisation, rather than cost cutting. Plenty of factors such as ageing equipment, incorrect load calculation, poor air distribution design, etc, add to the cost. Initially, refurbishing a seven-eight-year-old HVAC equipment, even if its functioning ‘fine’, seems to be a huge cost but in certain scenarios, the same has increased efficiency by 25-30% and would soon offset the cost incurred. When comparing it with modern five-star rated solutions available today, one can most definitely save 30-40% on electricity charges.”
Installing the right product is only the first step in the process. l things to do in a daily routine to ensure effective functioning of the HVAC system. Controlling and monitoring the units optimally is also a crucial practice that needs to be deployed through the operational lifecycle of the machine. Sudeep Ghoshal, ____, Reliance Industries, explains, “To conserve energy and optimise energy management, we’ve installed high performance centrifugal chillers with auto cut-off for higher efficiency. In addition, Variable Air Volume Dampers are installed in work-floor areas so that airflow can be controlled at various locations. Variable Frequency Drives too have been installed in AHUs to save energy. Apart from integrating these measures within the system, we also have used double glazed glass on the building facade to reduce heat absorption and thereby reduce energy consumption.”
Professionals in these sectors looking at upgrading or expanding operations are increasingly choosing to go for Variable Refrigerant Flow and VRV) systems with either BMS or electronic control system for tracking consumption in different zones to aid power conservation. Having deployed this at the company’s premises, Jai Agnani, VP, Head of Global Facilities and Logistics Operations, EXL Service, shares his insights on the same: “We ensure that there is a tight control by our onsite engineering teams, mapping to the actual occupancy times of the building. Monitoring and tracking energy consumption trends in order to take real-time corrective actions is also crucial to keeping costs lower.”
Another measure that Vishwanathan, director of Infrastructure at Capgemini, adopted is the use of thermafusers i.e terminal diffusers for HVAC temperature control, wherein each diffuser with inbuilt thermostat controls the temperature of the area it services. This controls leakage of conditioned air.
While HVAC solutions involve cost, especially in terms of energy, facility managers also walk a tight rope to ensure that HVAC cost savings do not interfere with employee satisfaction. Proper selection and maintenance of the pump; VFD on all electrical motors, AHU and cooling tower fan; keeping the approach of the plant/heat exchanges as low as possible by using automatic tube cleaning systems; routine cleaning of FCU, AHUs, coil and foil cleaning; and smart technologies for rooms, which sense occupancy levels and switch to energy saving mode in case of zero-occupancy — are some of the ways of maintaining a well-organised and balanced system to save on wastage and costs and also ensure right levels of cooling.
There have been several innovations in HVAC systems. Freon free gas, which protects ozone, is now available in the market but is a relatively expensive option. There was a time when the capacity of per ton of cooling system was 1.5 to 1.6KW per unit. However, the same is 0.53 to 0.48 which has reduced significantly.
In fact, today the industry has progressed to EC motors, which are readily available and more efficient by delivering the same output while using less power. Chillers are now VFD operated/manufactured.
Today, software can programme a number of equipment in one go. In the case of multiple chillers, the software can manage the start/on/off modulation automatically based on the indoor requirement and outdoor conditions. The software can also maintain high efficiency levels by adjusting the set points, maintaining the load sharing between multiple chillers. They can also adjust the operations of fans in cooling towers, pump operation as well as set a command to ensure the other chillers start. Additionally, they also take the responsibility of the entire process in a seamless manner. Instead of placing the entire load on a single plant, the load is well distributed to avoid machine overload.
Besides the technical selection, the efficiency of the system is also fairly dependent on the user or the maintenance team. There are certain maintenance schedules that need to be followed. For instance, alignment, filter and coil cleaning regularly plays a vital role in maintaining the efficiency and output. FMs realise that energy costs can make or break the bottom line and are evaluating their HVAC solutions to strike the right balance between being cost effective and guest efficient.
Some of the innovations in this vertical include LG’s high energy efficiency VRF systems is one of the most efficient in both air-cooled and water-cooled options. The system is coated with highest corrosion protection coating called Ocean Black. It also features magnetic bearing centrifugal chillers (oil-free) — 260 TR to 2200 TR with a green gas — world-class energy efficiency (COP up to 7.0) with lower footprint, lower noise levels and consistent performance over time. 75F, a wireless building automation solution for commercial buildings, launched 75F Smart Stat Zone Controller, which is known as the smartest commercial thermostat. It supports the new WELL building standard with immediate data insights for temperature, humidity, CO2, VOCs, light, sound and occupancy from inbuilt sensors. Each Smart Stat also has a unique radial touch user interface and includes 75F’s cloud-based wireless building automation platform for HVAC, indoor air quality, lighting and energy management, to achieve 30-50% energy savings in commercial buildings.
Three common mistakes to avoid during installation and maintenance of HVAC systems
By Sunil Khatwani, VP and business head, System Airconditioning Division, LG
1. Choosing the wrong installation contractor
Just choosing the lowest bid is the beginning of many problems. The credentials of the installer should be thoroughly checked before hiring. Choosing an expert AC installation company is the first step toward avoiding pitfalls like wrong equipment size, wrong ducting design, poor drainage system, poor quality of wiring, etc.
2. Considering the HVAC design late in the building/renovation process
For best results, installing such systems should not be just a matter of installing new units where the old ones used to be. An experienced HVAC installation contractor should be employed early in the building or renovation process to eliminate problems such as comfort complaints due to improper ventilation design, air quality concerns, poor energy efficiency, poor spacing for the outdoor units and installation delays, among others.
3. Poor indoor air quality (IAQ)
Maintaining good IAQ is vital for maintaining good health. It also results in higher productivity in workspaces and improves footfalls in retail spaces. However, since it is not an easily understood subject and not visible, installers often reduce the desired outdoor air ventilation in HVAC systems to cut down on capital and operating costs. There are many installations, especially in public spaces, where operators close the fresh air dampers to reduce operating costs. In addition, installation of smaller systems that do not permit fresh air intake, is done in larger spaces, to save cost and reduce the installation time.
The right methodology is to follow the established standards of ventilation in the system design and then choosing the right HVAC system to ensure that.