Types of Air Handling Systems Used In Paper Industry

An air handling unit (AHU) or air handling system are devices that used to circulate and regulate air as part of a heating, ventilating, air-conditioning (HVAC) system. An air handler is usually a large metal box that contains a blower, heating or cooling elements, filter chambers or racks, sound attenuators and dampers. The air handlers are usually connected to a ductwork ventilation system, that distributes the conditioned air through the building and returns it to the AHU. Its basic function is to take in outside air, condition it and supply fresh air to a building. All the exhaust air is discharged and depending on the required temperature of the conditioned air, the fresh air is either heated by a recovery unit or a heating coil or cooled by a cooling oil. At times, the air is directly discharged (supplied) and returned to and from the space served without ductwork. Normally, a heat/cooling recovery exchanger is fitted to the air handling systems for energy savings and increasing capacity. An AHU that's designed for outdoor use, typically on roofs, is known as rooftop unit (RTU). Some of the air from the rooms can be re-circulated by a mixing chamber in buildings where the hygienic requirements for air quality are lower and result in significant energy savings. Moreover, for controlling the ration between the return, outside and exhaust air, a mixing chamber has dampers even.

  Read More: Optimizing Air Handling Systems in the Pulp and Paper Industry

The main types of components from the return duct (input to the AHU), through the unit, to the supply duct (AHU output) are mentioned below.

  • Filters
  • Heating and cooling elements
  • Humidifier
  • Mixing chamber
  • Blower/Fan
  • Balancing
  • Heat recovery device
  • Controls
  • Vibration isolators

Types Of Air Handling Systems  

  • Housing Heat Exchangers
  • Custom Cooling Coils
  • Water-Glycol Heating Coils
  • Bare Tube Coils
  • Unit Heaters

A) Housing Heat Exchangers

Several types of housings that will accommodate virtually any application are offered, regardless of pressures, operating temperatures, or environmental conditions. The air handling systems are custom manufactured to meet your application requirements.

Slide-Out Housings
These are used in applications where the coils need to be easily removed, cleaning or replacement, to facilitate inspection.

Airtight Housings
These are built to ensure that there is no cross-contamination between the environment and the process air stream.

B) Custom Cooling Coils

Cooling coils, also referred as thermal fluid cooling coils, are idea for a wide variety of industrial cooling, heating and freezing applications such as freeze drying, vapor condensing, cryogenics, make-up air heating, heat treatment, process drying, heat recovery, area heating and cooling, process cooling, and heat dumps.

C) Water Glycol Heating Coils

The glycol and hot water coils are perfect for applications, where there's a probability to see freezing conditions on either the fluid side or air side of the coils. These coils possess good heat transfer properties, low volatility and provide bust and freeze protection with the proper glycol concentration selection. In numerous industrial applications, both propylene glycol and ethylene solutions are utilized. The propylene glycol is used where there's a potential contact with beverage, food or other consumable products or where reduced toxicity is of an environmental concern. The coils utilizing chilled water, hot water, cooling tower water or a water/glycol mix are ideal for a wide variety of industrial applications such as -

  • Heat recovery
  • Heat dumps
  • Make-up air preheating
  • Process drying
  • Comfort cooling
  • Heat treatment
  • Area heating
  • Dehumidification
  • Industrial cooling

D) Bare Tube Coils

The bare tube coils are coils that have tubes without fins. The fins are responsible mostly for a coils capacity and provide most of the heat transfer area. But, the problem with fins is that there is a chance of blockage with particulate in the airstream, which is difficult for coils that have tight fins spacing below 8 fins per inch. It’s highly recommended to use bare coils, as restricting the air flow will lead to coil capacity reduction and affect the entire process. These are commonly used in high-temperature applications, where there are particulates in the air stream, because the build-up of a product becomes a fire hazard. The bare tube coils are generally manufactured using stainless steel, carbon steel or exotic materials.

E) Unit Heaters

The unit heaters are used for a variety of applications including -

  • Food processing facilities and equipment
  • Textile factories
  • Dairy processing facilities and equipment
  • Power plants
  • Pulp/paper processing facilities and equipment
  • Petroleum/chemical plants
  • Heat recovery systems
  • Grain/seed processing facilities and equipment

Major Manufacturers of Air Handling Systems

Some of the major players in the air handling systems market are -

  • AAON
  • Carrier Corporation (also makes Bryant and Payne brands)
  • CIAT Group
  • Daikin Industries (also makes McQuay International, Goodman, and Airfel brands)
  • Emerson Network Power
  • Johnson Controls (also makes York International brand)
  • Lennox International
  • Rheem (also makes Ruud)
  • Trane
  • TROX
  • Mafna Air Technologies Inc.
  • Engineered Air

Market Insights :

Owing to rising concern for air quality and increasing HVAC applications in the sector of air conditioning, heating projects, the global market for air handling systems is expected to witness exponential growth during the forecast period. Due to high demand for infrastructure, Asia Pacific region and Middle East Region are expected to drive the market, as the capital of the regions rises. A rise in projects from district heating and cooling is expected to be witnessed from Middle East region and with centralized air systems from new smart cities. This is expected to drive the air handling systems market positively.

As per industry research, the global air handling systems market accounted for USD 7.11 billion and is projected to grow at a CAGR of 6.2%, during the forecast to 2026.