INDIRECT EVAPORATIVE COOLING (IEC)–ASSISTED FAHU / TFA
Energy Efficient Pre Cooling 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 air conditioning, IEC significantly lowers the sensible cooling load associated with fresh air intake—especially during peak summer conditions.
Evapoler’s IEC based Treated Fresh Air Unit provides an intelligent, energy efficient solution for conditioning outdoor air. By leveraging indirect evaporative cooling, the system pre cools 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.
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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- Fresh air temperature reduced by 6–12°C (climate dependent)
- 25–40% reduction in coil sensible load
- Smaller cooling coil size
- Reduced compressor run time or lower chiller TR requirement
- 25–40% lower power consumption vs mechanical cooling
- Improved overall AHU system COP
- Enables higher fresh air percentages at lower energy cost
- Ideal for buildings/processes requiring 100% fresh air
- IEC is a sensible cooling process
- AHU coil can be optimized for precise humidity control
- No chemical refrigerants
- Uses water + ambient air
- Polymeric heat exchangers ensure long life and corrosion resistance
- 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 IECAssisted 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) |
EPreCooling 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
CONTACT US
please write to us on: info@evapoler.com or service@evapoler.com
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