Treated Fresh Air Machine — Heat Recovery Wheel TFA
Integrated HVAC systems combining air handling, humidity control and refrigeration into a single reliable package — engineered for controlled-atmosphere and cold storage environments.
Integrated HVAC systems combining air handling, humidity control and refrigeration into a single reliable package — engineered for controlled-atmosphere and cold storage environments.
The Prime Coil treated fresh air machine is a heat-recovery-wheel-based air handling unit engineered for controlled-atmosphere and cold storage environments. Every treated fresh air machine we supply combines a rotary energy recovery wheel with premium blowers and filtration into a single reliable package — delivering conditioned fresh air to your storage or process area while recovering up to 82% of the energy that would otherwise be lost with the exhaust.
Why a treated fresh air machine matters for cold storage
Cold storage facilities have a genuine conflict at their heart. On one hand, product quality and worker safety require continuous fresh air ventilation — CO₂ from produce respiration builds up, ethylene from ripening fruit accelerates spoilage, and staff working inside need breathable air. On the other hand, every cubic metre of outside air brought in has to be cooled from ambient (35-40°C in Indian summers) down to storage temperature (-25°C in freezer rooms). The refrigeration energy required to condition that fresh air is often larger than the load from product respiration and heat leakage combined.
A properly engineered treated fresh air machine solves that conflict. The heat recovery wheel captures the cold energy from the outgoing exhaust air and transfers it to the incoming fresh air — pre-cooling incoming air by 15-25°C before it reaches the refrigeration coil. Result: the refrigeration system does 60-70% less work to condition the same volume of fresh air, and the plant’s total electricity bill drops significantly.
Premium components — Ostberg rotor wheels and Kruger blowers
Every Prime Coil treated fresh air machine is built around imported premium components with proven performance histories:
- Ostberg rotor wheels (Sweden) — the industry-leading rotary heat recovery wheels, engineered from precision-corrugated aluminium foil with hardened face edges for long service life. Wheel diameter available from 600 mm to 1,350 mm covering capacities from 1,000 to 10,000 CFM.
- Kruger blowers (Thailand) — high-efficiency centrifugal blowers with static pressure capability from 50 to 125 mmWG. Kruger has been supplying HVAC blowers to Asian and Middle Eastern industrial projects for decades — proven for reliability in continuous-duty environments.
- Made-in-India CE-certified sensors — indigenous CO₂, humidity and temperature sensors with 2-year warranty backing, providing precise atmospheric control for controlled-atmosphere storage.
- Siemens PLC automation — programmable control with HMI touchscreen options, on-screen and pen-drive data logging, and online access without static IP requirements.
Complete package — one supplier for design, build, commissioning
Traditionally, cold storage HVAC systems require coordinating multiple vendors — the air handler manufacturer, the heat recovery wheel supplier, the controls integrator, the ductwork contractor, and the commissioning agent. Prime Coil supplies the complete treated fresh air machine as an integrated package.
Standard scope includes:
- Complete AHU with heat recovery wheel and blowers pre-assembled
- Insulated ducting sized for your facility layout
- PUF-insulated panels and PPGI outer skin for thermal and structural integrity
- Siemens PLC controller with HMI touchscreen
- CO₂, RH, and temperature sensors positioned for optimal control
- Complete wiring, commissioning, and staff training
Energy recovery performance — 67% to 82% documented
Independent testing on Prime Coil treated fresh air machines documents 67% to 82% enthalpy recovery efficiency across the standard operating range. Higher efficiency at design conditions (matched airflow between supply and exhaust); slightly lower efficiency at partial loads. Site-specific performance calculations available during quotation based on your ambient conditions and storage requirements.
Custom-engineered for cold storage layouts
Off-the-shelf air handlers are engineered for office and commercial HVAC — they don’t handle the deep-freeze return air conditions, low-temperature seal requirements, or corrosive humidity levels found in cold storage. Every Prime Coil treated fresh air machine is custom-engineered for your specific application:
- Freezer-room versions with low-temperature bearings and seals
- Chill-room versions with condensate management for high humidity
- Controlled-atmosphere versions with tighter CO₂/O₂ control
- Multi-chamber versions serving multiple rooms from a single unit
Built to run, season after season.
Precise temperature & humidity control
CE-certified sensors monitor CO₂, humidity, and temperature at the room level. Siemens PLC modulates fresh air introduction and heat recovery wheel speed to hold conditions within tight tolerances — critical for controlled-atmosphere storage and pharmaceutical applications.
Energy-efficient integrated design
The complete package delivers up to 82% enthalpy recovery from exhaust air. On a facility running 5,000 CFM of ventilation continuously, that recovery translates to 15-25 lakh rupees per year in avoided refrigeration electricity costs — payback typically 2-3 years.
PUF-insulated ducting & panels
Polyurethane foam insulation with PPGI (pre-painted galvanised iron) outer skin provides thermal isolation and structural integrity. Prevents condensation on external surfaces even when cold air is being transported through warm plant rooms.
82% heat recovery with Ostberg rotors
Premium Swedish-made heat recovery wheels with precision-corrugated aluminium foil media, hardened face edges, and non-contact labyrinth seals. Documented recovery efficiency 67-82% across operating conditions with 15+ year service life.
Made-in-India CE-certified sensors
Indigenous NDIR CO₂ sensor transmitters, RH/temperature sensors, and control instrumentation with 2-year replacement warranty. CE certification confirms compliance with European electromagnetic and safety standards.
Siemens PLC automation
Programmable controller with HMI touchscreen options, on-screen and pen-drive data logging, up to 2 years log storage, online access without static IP. Standard Siemens platform ensures long-term spare parts availability and integrator familiarity.
Single-source design, build & commissioning
Prime Coil takes complete responsibility for the entire HVAC package — design, fabrication, installation, commissioning, and operator training. No coordination overhead between multiple vendors, no finger-pointing when problems arise, single accountability.
Custom-engineered for cold-storage layouts
Off-the-shelf commercial air handlers cannot handle deep-freeze return conditions or corrosive humidity levels. Prime Coil designs each unit specifically for your storage type — freezer, chill room, controlled atmosphere, or multi-chamber configurations.
Reliable, low-maintenance operation
Ostberg wheels have no wear parts other than drive belt (5-year life), and self-cleaning airflow keeps the wheel matrix free of buildup. Kruger blowers have sealed bearings with 40,000+ hour service life. Annual maintenance limited to belt inspection and filter change.
Specifications
| Type | Rotary heat recovery wheel TFA / AHU |
|---|---|
| Airflow capacity | 1,000 to 10,000 CFM |
| Static pressure | 50 to 125 mmWG |
| Energy recovery efficiency | 67% to 82% (enthalpy) |
| Heat recovery wheel | Ostberg (Sweden), 600 mm to 1,350 mm diameter |
| Blowers | Kruger (Thailand), centrifugal high-efficiency |
| Outer skin | PPGI pre-painted galvanised iron |
| Insulation | Polyurethane foam (PUF) |
| Control system | Siemens PLC with HMI |
| Data logging | On-screen + pen-drive, up to 2 years storage |
| Sensors | CO₂ (NDIR), RH, temperature — CE certified |
| Power supply | 415 V, 3-phase, 50 Hz |
| Storage temperature range | -25°C to +8°C (variant dependent) |
| Ambient design | Up to 45°C |
| Filtration | G4 standard, F7/F9/HEPA optional |
| Sensor warranty | 2 years replacement |
| Wheel service life | 15+ years typical |
| Blower service life | 40,000+ hours to bearing replacement |
Where it's used.
- Cold storage warehouses
- Controlled atmosphere (CA) storage
- Fruit & vegetable cold rooms
- Meat & poultry storage
- Dairy processing facilities
- Pharmaceutical cold rooms
- Mushroom cultivation chambers
- Research & test chambers
- Food processing facilities
- Blast freezer support ventilation
Product questions, answered.
Why does a cold storage facility need a treated fresh air machine?
Cold storage rooms cannot be completely sealed — produce respiration builds up CO₂, ripening fruit emits ethylene that accelerates spoilage, and staff working inside need breathable air. Some fresh air introduction is unavoidable. Without a TFA with heat recovery, every cubic metre of outside air (35-40°C ambient) has to be cooled to storage temperature (-25°C for freezers), consuming significant refrigeration energy. A treated fresh air machine recovers 67-82% of that cooling energy from the exhaust air stream, dramatically cutting the refrigeration load required for ventilation.
How does the heat recovery wheel work?
The wheel is an aluminium honeycomb structure that slowly rotates (about 10-20 RPM) between two air streams — incoming fresh air and outgoing exhaust air. As it rotates through the cold exhaust air (from your -20°C storage room), the wheel absorbs that cold. When it rotates into the incoming fresh air stream, it gives up that cold, pre-cooling the incoming air from 40°C ambient down to 5-10°C before it reaches your refrigeration coil. Enthalpy wheels with desiccant coating also transfer moisture, giving both sensible (temperature) and latent (humidity) recovery.
How much electricity does a TFA actually save?
Depends on your ventilation rate, ambient conditions, and storage temperature. As a rough guide, a 5,000 CFM TFA running continuously in Indian ambient (35°C average) serving a -20°C freezer saves approximately 15-25 lakh rupees per year in refrigeration electricity compared to conditioning the same fresh air without recovery. Payback on TFA capital cost is typically 2-3 years for continuous-duty operations.
Why do you use Ostberg wheels and Kruger blowers specifically?
Both components have proven performance histories and long-term parts availability. Ostberg is the industry-leading rotary heat recovery wheel manufacturer with over 40 years of experience — their wheel construction (precision-corrugated aluminium with hardened edges) delivers documented 15+ year service life. Kruger blowers have been proven in Asian and Middle Eastern industrial HVAC for decades. Using premium components with warranty support ensures our TFA units perform for their full design life without unexpected component failures.
Can the TFA be retrofitted to an existing cold storage?
Yes — TFA retrofits are common for facilities that recognise they are losing significant refrigeration capacity to poorly-managed fresh air ventilation. Retrofit scope includes: installing the TFA unit in the utility area, running supply and exhaust ductwork to the storage rooms, connecting to the existing electrical supply, and integrating with the plant's refrigeration controls. Typical retrofit takes 2-4 weeks with 1 week of storage room shutdown for final connections. Payback economics are often better than new installations because existing plants are typically losing more energy than they realise.
What sensors and controls come with the TFA?
Standard package includes NDIR CO₂ sensor transmitters, RH/temperature sensor transmitters at supply, exhaust, and room locations, Siemens PLC with HMI touchscreen, data logging up to 2 years, and remote access capability without static IP requirement. All sensors are CE-certified with 2-year replacement warranty. Additional sensors (ethylene, O₂ for controlled atmosphere, particulate for pharmaceutical) available on specification.
What maintenance does the TFA require?
Very little compared to conventional HVAC systems. Standard maintenance: filter change every 3-6 months depending on filter grade and ambient dust, drive belt inspection annually with replacement every 5 years, blower bearing inspection every 12 months. The heat recovery wheel itself is self-cleaning by airflow and typically requires no maintenance other than periodic seal inspection. Total annual maintenance cost is a fraction of the electricity savings the TFA delivers.
What's the typical delivery and installation timeline?
Standard sizes ship in 6-8 weeks from order confirmation. Custom sizes and multi-chamber configurations run 8-10 weeks due to design engineering time. Installation typically takes 2-3 weeks depending on ductwork complexity, with 1 week of commissioning and operator training after mechanical installation is complete. Total project timeline from order to operational: 10-14 weeks typical.
Every Prime Coil treated fresh air machine is engineered specifically for your cold storage — because the payback maths only works when the ventilation rate and heat recovery efficiency are matched to your actual operating conditions. Send us your facility details and we'll come back within 2 working days with the model, delivered price, and expected annual energy savings.
Capacities & model codes
Freezer Room TFA
Optimised for freezer room ventilation with room temperatures -18°C to -25°C. Low-temperature bearings, sealed motor housings, condensate freeze protection. Sizes matched to freezer volume and worker occupancy calculations.
- Freezer room design (-18°C to -25°C rooms)
- Low-temperature bearings and seals
- Condensate freeze protection
- Sized to worker occupancy calculations
- Compatible with hot-gas defrost coordination
Chill Room TFA
For chill rooms operating 0°C to +8°C — the largest cold storage segment covering fresh produce, dairy, meat, and pharmaceutical applications. Enhanced condensate management for the high-humidity operating range typical of chill storage.
- Chill room design (0°C to +8°C)
- Enhanced condensate management
- High humidity operating capability
- Compatible with fruit, dairy, meat storage
- Standard PLC control with HMI
Controlled Atmosphere (CA) TFA
Precision-controlled fresh air introduction for controlled atmosphere storage — tight CO₂/O₂ management for apple, pear, kiwi, and other CA-suitable produce. Nitrogen backup integration for CA generator systems.
- Precision CO₂/O₂ control
- Tight sealing for CA storage integrity
- Nitrogen system integration ready
- Apple, pear, kiwi, and similar produce
- Extended storage life applications
Multi-Chamber TFA
Single AHU serving multiple storage rooms with independent temperature and humidity setpoints. Cost-effective for facilities with 3-8 storage chambers where individual units per room would be uneconomical. Zone dampers and independent room controls included.
- Up to 8 chambers per unit
- Independent room temperature/humidity setpoints
- Zone dampers with modulating control
- Central PLC with per-room HMI
- Cost-effective for multi-room facilities
Tell us your daily requirement.
Share your output target, product and ambient conditions — we'll specify the machine and the plant around it.