Treated Fresh Air Unit (TFA)

EnergyEfficient PreCooling for Fresh Air Systems

Indirect Evaporative Cooling (IEC) units are increasingly being adopted as Treated Fresh Air (TFA) Units or Fresh Air Handling Units (FAHUs) to reduce the cooling load on conventional Air Handling Units (AHUs). When integrated with mechanical airconditioning, IEC significantly lowers the sensible cooling load associated with fresh air intake—especially during peak summer conditions.

Evapoler’s IECbased Treated Fresh Air Unit provides an intelligent, energyefficient solution for conditioning outdoor air. By leveraging indirect evaporative cooling, the system precools fresh air at a fraction of the energy required by conventional refrigeration, resulting in:

  • 30–50% reduction in fresh air cooling load
  • 25–40% electrical energy savings
  • Lower operating costs and reduced carbon footprint

The system can be retrofitted to existing FAHUs or supplied as a standalone TFA unit.

Description

Key Technical Difference

  • Conventional FAHU relies entirely on mechanical cooling, making it energy intensive when handling large volumes of fresh air.
  • IEC-assisted FAHU removes a significant portion of sensible heat using low-energy evaporative cooling, allowing the cooling coil to focus mainly on latent load control.

Working Principle of IEC PreCooling

  • Outdoor air passes through the dry channel of the IEC, reducing DBT and WBT.
  • A secondary air stream is cooled via evaporative cooling in the wet channel.
  • Sensible heat transfer occurs across a crossflow polymeric heat exchanger (SenHex).
  • Fresh air temperature is reduced without adding moisture.
  • Precooled air enters the FAHU cooling coil at a lower temperature, reducing chiller/compressor load.

Benefits of Using Evapoler Coolator® (IEC) for Pre-Cooling

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❄️ Reduction in Cooling Load
  • Fresh air temperature reduced by 6–12°C (climate dependent)
  • 25–40% reduction in coil sensible load
⚙️ Lower Chilled Water / DX Capacity
  • Smaller cooling coil size
  • Reduced compressor run time or lower chiller TR requirement
⚡ Energy Savings
  • 25–40% lower power consumption vs mechanical cooling
  • Improved overall AHU system COP
🌬️ Improved Indoor Air Quality
  • Enables higher fresh air percentages at lower energy cost
  • Ideal for buildings/processes requiring 100% fresh air
💧 Humidity Control Maintained
  • IEC is a sensible cooling process
  • AHU coil can be optimized for precise humidity control
🌎 Green Cooling
  • No chemical refrigerants
  • Uses water + ambient air
  • Polymeric heat exchangers ensure long life and corrosion resistance
🏅 Certified Sustainability
  • COOLATOR® is GEM EcoCertified (ASSOCHAM
  • Supports ESG and decarbonisation goals

Comparison: Conventional FAHU vs IEC Assisted FAHU

Design Basis (Common for Both)

Parameter Value
Outdoor Air Flow 10,000 CMH (≈ 6,000 CFM)
Outdoor Condition 42°C DB / 24°C WB
Supply Air Condition 16°C DB
FAHU Type 100% Fresh Air
Coil Leaving Air RH ~90%

Savings in TR with IEC Assisted FAHU

Item Conventional FAHU IEC Assisted FAHU
Air Flow 10,000 CMH 10,000 CMH
Coil Inlet DBT 42°C 30.1°C
Supply Air DBT 16°C 16°C
Coil ΔT 26°C 15.2°C
Cooling Load 25 TR 13.6 TR
TR Reduction – 11.3 TR (≈45% Reduction)

Pre-Cooling Capacity of Evapoler Coolator® (IEC)

Model Airflow (CMH / CFM) Pre-Cooling Capacity (kW / TR) Total Power (kW) EER (Delhi) Noise (dBA)
Coolator® 10 10,000 / 6,000 38 / 11 3.3 44 ≤ 70
Coolator® 17 17,000 / 10,000 63 / 18 8.0 30 ≤ 70
Coolator® 25 25,000 / 15,000 95 / 27 9.7 37 ≤ 70
Coolator® 34 34,000 / 20,000 126 / 36 14.4 33 ≤ 70
Coolator® 42 42,000 / 25,000 158 / 45 18.8 32 ≤ 70

Advantages of Evapoler TFA (Treated Fresh Air Unit)

  • Energyefficient alternative to ERVs, heat pipes, and airtoair heat exchangers
  • Low lifecycle cost with minimal maintenance
  • Customizable with plug fans or EC fans
  • Suitable for retrofits or standalone installations

Related products

EVA-500-HS-3

EVAPORATIVE COOLERS (EVA 500-HS)