Fan wheels for air handling units

Reduce component diversity, increase energy efficiency


Citizen Industries Limited (Ahmedabad, India)



  • Plug fan wheels for AHU
  • Increased energy efficiency


  • Analysis of the existing air handling units
  • Determination of the optimal fan wheel
  • Switch to punker General HVAC fan wheels in AHU  


  • Reduction of fan wheel variety by 90%
  • Energy efficiency of fan wheels for AHUs increased by 5%

Project overview

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 General HVAC fan wheels.

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.

punker Case Study AHU

Our Client

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 government, public sector or private 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

Solution & Results

punker felt they could support this challenge with the then newly introduced General HVAC fan wheels. General HVAC 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. These fan wheels work best in a pressure range from 1.500-2.500 Pa (6 – 10 in. WG – AMCA Class II) and are available in a diameter range of 225 – 1000 mm (9ʺ to 39 3/8ʺ). The welded steel design option 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 General HVAC 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 General HVAC fan wheels would allow for a straightforward plug fan design. punker supplies the 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 General HVAC fan wheels 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 fan wheels fan wheels.

Citizen places orders with variable quantities, based on the demand for each respective AHU project. Due to the standardized character of the General HVAC fan wheels, 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 General HVAC fan wheels offered another substantial advantage for our client: Citizen now sources only 19 different fan wheels from punker, which reduces the number of different components by 90%.

What our clients say

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 –

Fan Wheels for Air Handling Units

The General HVAC fan wheels from punker are particularly suitable for plug fans and plenum fans used in unhoused applications such as air handling units. The fan wheels of the General HVAC Line are designed for high energy efficiency, low noise emission, low weight and optimal use of the available space and offer with a good price-performance ratio.

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