• Cooling India
  • Mar 15, 2017

“Practice Ancient Architectural Designs using Natural Ventilation”

Ensavior is a comprehensive solutions provider company engaged in design, engineering, sales, marketing and service of HVAC Products & Services, Ventilation & IAQ Services. Dinesh Semwal, Managing Director, Ensavior sheds light on steps for improving energy efficiency and indoor air quality, services and products offered by the company, growth drivers of the sector in an e-mail interaction with Cooling India


What are the steps need to be taken to improve energy efficiency and indoor air quality?

Energy Efficiency

HVAC systems consume about 40% of the energy in buildings. To achieve a significant reduction in energy consumption apart from the standard energy-efficiency methods, innovative technologies should be implemented, including renewable energy.
High efficiency chillers, variable speed drives, variable air volume boxes, and right sizing of chilled water and condenser pumps, deploying high efficiency compressors, demand-based controls, thermal storage systems are some of the energy efficient techniques that can be adopted to achieve higher efficiency. Such measures can help reduce energy consumption of a HVAC system.

Indoor Air Quality (IAQ)

Indoor air quality is a major concern to businesses, building managers, tenants and employees because it can impact the health, comfort, well-being and productivity of building occupants. Most of us spend up to 90% of our time indoors and many spend most of the working hours in an office environment. Studies show that indoor environments sometimes can have levels of pollutants that are actually higher than levels found outside.

Indoor air quality is not a simple, easily defined concept; it is a constantly changing interaction of complex factors that affect the types, levels and importance of pollutants in indoor environments.

Controlling indoor air quality involves integrating three main strategies:

• Manage the sources of pollutants either by removing them from the building or isolating them from people through physical barriers, air pressure relationships, or by controlling the timing of their use.

• Ventilation helps remove or dilute indoor airborne pollutants coming from indoor sources. Carefully evaluate using ventilation to reduce indoor air pollutants where there may be outdoor sources of pollutants.

• Filtration to clean the air of pollutants. Advanced designs of HVAC system have started to incorporate UVGI (Ultra Violet Germicidal Irradiation) system that destroys airborne microbes and odor. This reduces the level of contaminants and improves indoor air quality (IAQ).

What are the solutions and services offered by the company keeping in mind rising global warming?

Global warming and climate change have been wreaking havoc with weather and temperatures across the planet. Temperatures are on the rise in summers, winters may be warmer in certain places, rainfall patterns are changing and the use of air-conditioners is on the rise. Worldwide power consumption for air conditioning alone is forecast to surge 33-fold by 2100.

Ensavior is offering the following energy saving equipment and systems for the HVAC industry:

Thermal Energy Storage (TES) Systems

Conventionally, chillers are selected for peak air-conditioning load to satisfy the maximum cooling demand, which occurs only for a few hours per year on real time basis, and thus spend majority of their operational life at reduced capacity and low efficiency.

TES systems, on the other hand, use optimum capacity chillers for using cheap off-peak electricity to store chilled water at night which can be used for meeting the peak cooling demands during the day.

While TES shaves off the peak connected demand due to significant reduction in installed chiller capacity, this in turn results in a healthy plant load factor, as well as reduced connected demand load. This on a large scale collectively contributes to a better demand management at grids and subsequently reduces the requirement of setting-up new power plants.

The TES system helps lower operational costs by enabling the shifting of energy consumption of chillers from peak hours (day) to off peak cost hours (night). It is prudent to note that chillers perform with much better efficiency and lower power consumption when operated at low ambient temperatures during night time as compared to day time. This contributes to a considerable energy and operational cost savings on ongoing basis.

Chilled Water Thermal Storage systems are ideally suitable for provision of chilled water backup for mission critical facilities like data centers and high tech manufacturing.

Ultra Violet Germicidal Irradiation (UVGI) Systems

UVGI systems are installed in air handling units of HVAC to overcome the following usual problems encountered with air-conditioning.

Increasing Electricity Consumption

The condensation of moisture around the cooling coils permeates growth of algae, mold, mildew bacteria and viruses, thus reducing the heat transfer efficiency and airflow of the AHU; which in turn increases the power consumption.

Deteriorating Indoor Air Quality (IAQ)

The contaminated air while passing over the coil and further contamination from the work place deteriorates the IAQ leading to Sick Building Syndrome and increased sickness of the inhabitants of the building. In case of cold storage, it leads to contamination and deterioration of food products.

Increased Operation and Maintenance Cost

Due to contamination of coils, difficulties are experienced to maintain clean and contamination free air.

Cleaning of Cooling Coils

The installation of UVGI, practically, eliminates cleaning of cooling coils, thereby, leading to reduction in maintenance cost and elimination in down-time of air-conditioning system.

Pressure Independent Control Valves (PICV) and Automatic Balancing Valves

An effective and efficient HVAC system must provide correct energy output when and where required. Water circuit balancing is essential to ensure that chilled water system delivers correct flows to all terminal units in an HVAC circuit. Proper hydronic balancing is the key to making an HVAC system perform efficiently and most cost-effectively. To cater to this critical feature we are offering PICV and Automatic BalancingValves.

Pumping System

Variable-speed pumps significantly reduce energy use by precisely matching a HVAC system’s level of operation to the cooling load, which can vary throughout the day based on the building’s needs. They can maintain occupant set point without resorting to inefficient full-on, full-off system cycles.

This on/off cycle, which is a common function of popular fixed-speed systems, means the system is always running at full load for a given ambient condition, whereas an air-conditioning system utilizing variable-speed pumping technology is capable of operating under much more efficient part-load conditions.


Indoor air quality is a major concern to businesses, building managers, tenants and employees because it can impact the health, comfort, well-being and productivity of building occupants. Most of us spend up to 90% of our time indoors and many spend most of the working hours in an office environment. Studies show that indoor environments sometimes can have levels of pollutants that are actually higher than levels found outside.


What are major areas where you are contributing to?

• Chilled Water Backup for Mission Critical Facilities
• Demand Side Management
• Energy Efficiency
• Indoor Air Quality.
• ‘Chilled Water Backup for Mission Critical Facilities and Demand Side Management’,

Could you cite an example on how your assistance has helped the industry in achieving the same?

Chilled Water Backup for Mission Critical Facilities

In data centers with high power and heat densities, a power outage can cause rapid temperature increases. This is because cooling systems temporarily shut down, while servers keep producing heat because they are on UPS.

The response of mechanical cooling equipment to power disturbances varies, depending on the size and duration of the disturbance. Once chillers shut down, it can take several minutes for them to resume cooling after power is restored— too long to prevent damage to IT equipment.

Data centers provide standby generators for chillers. However, they take several seconds to start up, after which it can take several minutes to restart the chillers.Chilled Water Thermal storage can extend the ability to cool data center IT equipment in the event of a power failure by using thermal reserves to provide temporary cooling during a power outage.

In a prestigious Data Center of Bengaluru, an online Chilled Water Thermal stratification storage system with Radial Diffusers of 375 RT-Hr capacity (Six numbers of insulated storage tanks holding 2,40,000 liters chilled water) has been successfully installed to provide 30 minutes chilled water storage backup.

Demand Side Management

In a District Cooling Plant project in India, where Chilled Water Thermal Storage Tank of 10000 RT-Hr capacity is installed, is our landmark installation. Out of the total HVAC load requirement of 10000 RT, 2535 RT load is catered by Thermal Storage thereby reducing the Installed Chiller Capacity down to 7500 RT.

Each 2500 RT Chiller accounts for approximately 1482 KW, its primary pump approximately 125 KW, and its cooling tower condenser pump around 188 KW of electrical load. Hence, considering the elimination of 2500 RT chiller and its related equipment, the subsequent downsizing of connected electrical demand saved is about 1795 KW (1994 KVA) which would have been required otherwise.

This has not only benefitted them in saving about 2805 KVA DG back-up capacity but also allows them to use only 2 Nos. 2500 RT Chillers with CHW TES, operating mostly around the year. Only during peak months (May-June-July) they use their third chiller which facilitates them massive demand management on monthly basis.


Practice Ancient Architectural Designs using Natural Ventilation and Evaporative Cooling techniques to best possible extent.


Please elaborate on technological innovations incorporated in your products.

TES Systems: The state-of-the-art radial diffuser design for TES Tanks ensures proper stratification of hot and cold zone throughout the cycles keeping tank volume (water requirement) to a minimum. Radial diffusers made from stainless steel are self-supported type and installed during tank erection. Strong structural design of the radial disc diffuser is able to handle the shocks of the water hammering and surging etc. They are 100% maintenance free. The octagonal diffusers are made from PVC and hanged from roof structure of the tank, are weak to absorb the shocks of water hammering and surging etc., resulting in periodic maintenance checks.

PICV: The FlowCon SM PICV, is the most advanced PICV on the market today, which can secure points for the building’s LEED certification. Here’s how the FlowCon SM valve can improve the green credentials of today’s building projects.

• Commissioned either through the valve display or via the feedback signal. The data can be used to verify the flow through each unit is as specified.

→ Guaranteeing the prevention of overflow in fully open and part open conditions, have 100% authority at all times and is independent of pressure fluctuations. This leads to reduced system pressure drop and a consequential reduction in pump energy use. The accurate control of flow rates at all conditions result in temperature differences across the coils being closer to design therefore increasing chiller efficiency and reducing pump frequency.

→ Increases the accuracy in water flow control with the pressure independent feature preventing flow rate fluctuations and consequentially temperature changes with variations in pressure. The FlowCon PICV feedback option ensures that the valve can be integrated into a permanent monitoring system to ensure that the building performance meets the required comfort criteria.

→ Possible to link the FlowCon SM valve to the VFD pump and thereby ensure the optimal operation. It has an innovative feature, that it can correspond directly the actual flow rate to the BMS system without considering the exact differential pressure. It further more holds the option of direct verification of actual valve performance, settings and possible error codes, which can be used for easy building maintenance.

What are your suggestions to the Indian HVAC system managers?

• Practice Ancient Architectural Designs using Natural Ventilation and Evaporative Cooling techniques to best possible extent.

• Correct implementation of solar shading systems can greatly contribute to reduced heat gains and subsequently lower the overall HVAC System sizing.

• Focus beyond Net Zero Energy to Net Positive Energy buildings.

• Those who are already skilled in HVAC systems will find that “greening” their knowledge simply requires that they become familiar with the latest technology.


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