Industrial grade PLC for HVAC Solutions in Industries
                     INDUSTRIAL GRADE PLC 
FOR HVAC SOLUTIONS IN INDUSTRIES
www.messungautomation.co.in 
Messung's solutions are designed to share 
information and make sure your  systems 
work together maximizing both comfort 
and energy efficiency while reducing 
energy expenses. Whether new 
construction or retrofit applications, 
Messung’s expert can help you to design, 
install, integrate and maintain your 
control system with efficient energy 
management. Messung's solutions have 
the flexibility and scalability to adapt, and 
deliver results for your building 
environment.
www.messungautomation.co.in 
About AHU
An Air Handling Unit (AHU) regulates and circulates air as part 
of a heating, ventilating and air-conditioning (HVAC) system. It 
consists of a blower, heating or cooling elements, filter racks, 
sound attenuators and dampers. It is usually connected to a 
ductwork system that distributes the conditioned air through 
the building and returns it to the AHU.
Sometimes, AHUs discharge and admit air directly to and from 
the space without ductwork.
With the growing emphasis on energy performance in 
buildings, and new standards to study and improve energy 
efficiency, buildings need automation & control systems to 
achieve high levels of energy efficiency.
HVAC is one area where huge amount of power is consumed, 
and where plants with energy-optimised design, installation 
and commissioning are a must.  Automation with AHU-specific 
functions ensures more systems' energy efficiency, operational 
reliability and availability. Automation also monitors room and 
outdoor temperatures to reduce cooling energy needs and 
improve comfort levels.
www.messungautomation.co.in 
A Case Study
“Our Customer is a Bengaluru based 
company involved into manufacturing of 
Products like Metal Working Tools, Mining, 
Foundation Drilling cutting Tools, 
Tungsten carbide wear components etc. 
required for Industries like Aerospace, 
Additive manufacturing, Machine Tool 
Industry, Energy, Earthworks.”
www.messungsmart.com 
Basic AHU for Coating Room
The project required Messung’s solution to 
ensure that the coating room is maintained 
under 5 Pa Negative pressure with respect to 
ambient and within the room temperature 
zone of 21.1 Deg. C to 24.4 Deg. C and RH 
Zone of 40% to 60%. Since the system is 
working round the clock, it is necessary to 
control the system in such a way that 
minimum power is consumed by the HVAC 
system. 
In addition, in case of any process gas leakage 
in the coating room, fresh air supply and 
exhaust to be operated at the it’s full capacity 
to exhaust the leaked gases promptly.
www.messungautomation.co.in 
Messung’s solution
• Messung proposed an AHU System which can maintain acceptable room conditions using 2 stage evaporative 
cooling or using chilled water cooling coil, depending on the ambient air conditions throughout the day and 
year. 
• Variation of ambient conditions in Bengaluru through the day and year is such that the ambient air conditions 
can be used to maintain the desired room conditions for much of the time, mainly in cooler nights and winter 
season.  
• Since the plant is working round the clock, Messung decided to make use of favorable ambient conditions to the 
best possible extent to minimize the power consumption by AHU system.
• Messung divided the variation of ambient air conditions throughout year, into 3 parts:
– Mode -I, where in the ambient condition is hot and dry, where either single stage or 2 stage evaporative 
cooling can be used to maintain room conditions.
– Mode – II, Monsoon conditions with high RH and not so cold temperature, wherein conventional chilled 
water cooling coil will be used to cool and de humidify and maintain the designed room conditions
–  Mode – III, typically winter conditions, Messung proposed to modulate return air and cold fresh, as well as 
single stage evaporative cooling to maintain the designed room conditions.
www.messungautomation.co.in 
Proposed Control System 
www.messungautomation.co.in 
Salient Features
• Versatile CPU with large 
Input/Output signals handling 
capacity
• Capturing real time data for 
Temperature, Relative Humidity, 
Running hours for AHU 
• Large program memory for 
implementing complex Relative 
Humidity formulas
• Incorporating of Program 
Algorithm based on Psychrometric 
chart readings
• Connection of CPU with 15 nos. of 
VFD’s on MODBUS RTU control 
network
• Prompt monitoring & controlling 
the entire system using HMI
www.messungautomation.co.in 
Psychrometric Chart
www.messungautomation.co.in
Psychrometric Chart
www.messungautomation.co.in
MESSUNG is an Automation Partner capable of Supplying Solutions to any 
Project of Air Handling Units and Environment Control Systems. 
Messung's NX-ERA Series of PLCs for industrial automation help to monitor, control and optimise AHUs to ensure 
performance and efficiency of HVAC systems. Messung's AHU control systems feature these latest technology PLCs with 
user-friendly interface to monitor and control each component of the AHU including fans, heating, cooling, 
humidification, heat recovery, etc. The systems offer design flexibility with variable size options and a wide range of 
choices to make your facility more productive and energy-efficient.
www.messungautomation.co.in 
THANK YOU
Contact us
MESSUNG SYSTEMS PVT. LTD.
501, 502 & 503 Lunkad Sky Vista, Viman Nagar, Pune, India - 411 014.
+91 20 6649 2800 | [email protected]
www.messungautomation.co.in