Browsing Tag

fan wheel selection


Case Study: Citizen Industries Limited

Citizen Industries Limited has been a leading manufacturer of Air Handling Units (AHU), Lab furnishing equipment and Biotech equipment in India for three decades. In 2016, punker helped Citizen reduce the number of different fan wheels used in their AHUs by 90% to only 19 by switching to the punker D-Series.

Streamlining the vast number of components used in their products saved our client time and money and, at the same time, made the Citizen Air Handling Units even more efficient – helping their clients save operating costs in turn.

Citizen Industries Limited was established in 1987 with its headquarter in Ahmedabad, India. The company is a leading manufacturer of Air Handling Units (AHU), Lab furnishing equipment and Biotech equipment in India. They serve renowned goverment, public sector or privat company clients from various industries such as Agriculture, Education, Food & Beverage, Health Care, Pharmaceuticals, Petroleum Industry, or Textiles and Garments. Citizen sets a high value on designing energy efficient, low maintenance and highly reliable HVAC equipment.

Citizen Industries and punker had been working closely for more than 23 years in selecting the optimal fan wheels for each AHU requirement, always aiming for maximum energy efficiency. This lead to a large fan wheel variety, as for each project, the optimal fan wheel execution of width, hub, bore and inlet cone was selected. In total, punker supplied 205 different variations of the HLS 70, HLR 70, and R63D2 series, as well as another 69 corresponding inlet cones. The administrative effort of product drawings and technical documentation, as well as the production and transport time, grew with the number of different items.

Citizen started to look into the option of building their own plug fans instead of purchasing them from a supplier. The goal was to offer a high efficiency plug fan that could be installed in any future air handling project, irrespective of the required air flow and pressure requirements.

  • Supply fan wheels for new AHU plug fans
  • Increase overall system efficiency
  • Reduce overall lead times and inventory of varied items

punker felt they could support this challenge with the then newly introduced fan wheel series Dclassic. Dclassic is a highly standardized fan wheel series specially designed for use in plug and plenum fans for air handling and ventilation units. The mechanical efficiency static of 75% is perfectly suited to exceed our client’s energy efficiency requirements. The Dclassic works best in a pressure range from 1.500-2.500 Pa (6 – 10 in. WG – AMCA Class II) and is available in a diameter range of 225 – 1000 mm (9″ to 39 3/8″). This welded steel design with a maximum tip speed 75 m/s (246 fps) is powder coated by default. The well proven Taperlock hub system makes it compatible with any shaft motor option. The use of VSD (variable speed drive) allows for actuating various operating points.

punker introduced the concept of this new fan wheel series to Citizen and presented an analysis showing that the future use of Dclassic fan wheels could eliminate 80% of the article variety that Citizen had bought from punker over the past 20 years. In combination with supporting services from punker, such as a customized DLL file with performance data for Citizen’s own AHU configuration software, the use of Dclassic would allow for a straightforward plug fan design. punker supplies the Dclassic fan wheels with a corresponding inlet cone for optimum air flow. The inlet cone ED 11 is equipped with a connector for airflow measurement by pressure tap, allowing for easy monitoring and adjustment of the AHU’s system performance.

A comparison of the performance curves of previously used fan wheels and the Dclassic showed an increase in static efficiency of up to 5%. Sample wheels of different widths were supplied for comparison measurements at the Citizen works, which confirmed the calculated performance. Our client thus completed the design of their future plug fans and place the first order of Dclassic fan wheels.

Citizen places orders with variable quantities, based on the demand for each respective AHU project. Due to the standardized character of the Dclassic fan wheel series, punker can deliver them in short cycle times, optimize shipping volumes and container loads according to demand, and provide safe packaging for sea transport.

The switch to the Dclassic fan wheels offered another substiantial advantage for our client: Citizen now sources only 19 different fan wheels from punker, which reduces the number of different components by 90%.


Our main objective was to design our own plug fan and increase the system efficiency of our Air Handling Units. On top of that, we reduced our component variety to a sizable quantum which helped us save time and inventory carrying cost.

Kamalesh Mehta
CEO | Citizen Group –


A standardization like this leads to a WIN-WIN-situation for both the customer and manufacturer side: fast availability, cost-efficiency, reference diversity, etc. With this in mind, the development of the D-Series had two main objectives: 1) Standardization 2) Simultaneous opportunity of a new development according to the highest technological requirements.

Juergen Beinke
Global Sales Director (CEO) | punker Group


puncat WEB

Our puncat software for the selection of fan wheels is an important tool for our customers, prospective clients and sales staff. After 20 years of service, it was time to make puncat fit for the future – and the web.
The last software version

The last software version

For almost 20 years now, punker has been offering its customers the software “puncat” as a supporting tool for selecting the optimal fan wheel for each application. Until today, clients worldwide were provided with numerous versions on Floppy-Disk, CD-ROM, DVD, USB flash drive or via direct download from our website. In the course of time, new fan wheel series have been added, outdated series deactivated, data sheets and performance data updated in order to offer our customers the optimal solution at any given time.

However, these proceedings entail some risks: during a recent customer visit, I found myself confronted with a puncat CD-ROM (Version 3.0) dated 2006 and was asked to show the client where exactly the ErP-calculation was handled. We went straight to the punker website where they registered for the customer area, downloaded the latest version of puncat and reinstalled it. They not only have access to the ErP-calculation now, but also to the latest database content and best fan wheel solutions available. Unfortunately, this customer was likely not the only puncat user working with an outdated version of our fan wheel selection software.

In order to offer our customers an even better service and, above all, the latest products and current performance data, we decided to look into alternative, state-of-the-art solutions for puncat. It was agreed: we need a web-based solution for our customers!

During the first project kick-off meeting with our web agency wigital and the creator of the puncat Software, Kirsten Controlsystems, we decided to seize the opportunity and put the entire software to the test. That is how the completely overhauled puncat WEB came to live with numerous new features:

  • always up to date and available worldwide
  • thanks to responsive design usable with desktop, tablet and other mobile devices
  • a clear appearance in dependence on the punker Group’s corporate design
  • an intuitive und easy operation
  • filter functions such as industry suitability, mode of operation and fan wheel series
  • prioritization of search results by different criteria such as smallest wheel diameter or lowest shaft power
  • consideration of ErP-conformity (Energy related Products – European Parliament rule for an environmentally responsible design of energy related products).
  • new performance data: at the beginning of this year, our lab carried out innumerable measurements to update the database

We are proud to present you with the first web-based fan wheel catalogue by punker. All you need to do to get started is register on our website (if you are not a registered user yet) and you are ready to discover the variety of our outstanding, energy efficient fan wheels. I am sure you will find the perfect fan wheel for your application.punk_puncat_online-banner_203x230px

If you feel you cannot find the right standard wheel for your specific needs, do not worry: we still have a special solution or two up our sleeves that will suit your application perfectly.
Please do not hesitate to contact us directly. We will attend to your request right away.

Have fun discovering the new puncat WEB!

Please be aware that as of today, all prior versions of the puncat software are void!