Description
AOVH-35 Fan-Driven Air-Oil Cooler
The AOVH-35 is a high-capacity industrial air-oil cooler engineered for large hydraulic systems, heavy-duty lubrication circuits, and high-horsepower industrial equipment that generate substantial heat. With its oversized core, high-flow fan assembly, and rugged construction, the AOVH-35 is ideal for demanding applications such as steel processing machinery, large hydraulic presses, marine systems, industrial gearboxes, and high-duty-cycle manufacturing cells requiring consistent thermal stability under continuous load.
AOVHR Two-Pass & Relief Bypass Option
For enhanced cooling performance and added hydraulic protection, the AOVH-35 can be upgraded to the AOVHR configuration. The AOVHR option routes oil through the cooling core twice—significantly improving heat transfer—and includes an integral relief bypass valve designed to protect the system from excessive pressure during cold starts or when operating with high-viscosity fluids.
- Two-pass oil circuit: Doubles cooling exposure for maximum heat dissipation.
- Integral relief bypass: Typically available in 30 psi or 60 psi settings.
- Typical flow range: For AOVHR-35-2, designed for approximately 6–80 GPM.
- Performance ratings: 300 psi maximum pressure and 400°F maximum operating temperature.
AOVH-35 Specifications
- Model: AOVH-35
- Series: AOVH industrial air-cooled oil cooler
- Cooling Type: Fan-driven, air-cooled oil cooler
- Maximum Operating Pressure: 300 psi
- Maximum Operating Temperature: 400°F
- Dimensions (in): A: 17.50, B: 41.12, C: 15.75, D: 32.25, E: 26.00, F: 28.75, G: 30.25, K: 12.75, L: 27.12, M: 20.00, N: 33.12, P: 42.12
- Connections: 2-1/2" NPT
- Approximate Net Weight: 315 lb
AOVH / AOVHR Series Overview
The Thermal Transfer AOVH and AOVHR series of industrial air-oil coolers provide efficient and compact thermal management for hydraulic and lubrication systems across a broad range of industrial applications. These coolers are widely used in injection molding, hydraulic power units, gear drives, machine tools, marine equipment, torque converters, and other systems requiring long-term, reliable cooling performance. AOVH models use a one-pass oil path suitable for standard applications, while AOVHR models add a two-pass flow route and integral relief bypass for enhanced cooling and system protection.
Key Features & Applications
- High-efficiency fin-and-tube heat exchanger for industrial-duty cooling.
- Fan-driven airflow provides consistent, predictable heat rejection.
- Compact but rugged cabinet design for simplified installation and long service life.
- One-pass (AOVH) or two-pass (AOVHR) flow options available.
- Suitable for hydraulic presses, gearboxes, HPUs, marine equipment, and processing machinery.
- Integral bypass option on AOVHR models protects equipment during cold-start or high-viscosity operation.
Construction, Ratings & Materials
Pressure & Temperature Ratings
| Maximum Operating Pressure | 300 PSI |
|---|---|
| Maximum Operating Temperature | 400°F |
Standard Materials of Construction
| Tubes | Copper |
|---|---|
| Fins | Aluminum |
| Turbulators | Steel |
| Fan Blade | Aluminum with steel hub |
| Fan Guard | Zinc-plated steel |
| Cabinet | Steel with baked enamel finish |
| Manifolds | Steel |
| Connections | Steel |
Model Weights
| Model | Net Weight (lb) |
|---|---|
| AOVH / AOVHR-5 | 67 |
| AOVH / AOVHR-10 | 78 |
| AOVH / AOVHR-15 | 90 |
| AOVH / AOVHR-20 | 110 |
| AOVH / AOVHR-25 | 157 |
| AOVH / AOVHR-30 | 190 |
| AOVH / AOVHR-35 | 315 |
| AOVH / AOVHR-40 | 350 |
AOVHR Two-Pass Flow Ranges
| Two-Pass Model | Typical Flow Range (GPM) |
|---|---|
| AOVHR-5-2 | 4–50 |
| AOVHR-10-2 | 4–60 |
| AOVHR-15-2 | 4–60 |
| AOVHR-20-2 | 4–80 |
| AOVHR-25-2 | 4–80 |
| AOVHR-30-2 | 4–80 |
| AOVHR-35-2 | 6–80 |
| AOVHR-40-2 | 8–80 |
Installation & Piping Notes
Standard fan rotation is clockwise when viewing the motor shaft. AOVH/AOVHR coolers are typically mounted horizontally with airflow drawn through the core. Refer to dimensional drawings for mounting hole spacing, motor bracket orientation, and fan projection. Note that AOVH-5 and AOVH-10 mounts are rotated 90°.
AOVH one-pass models route oil from the lower inlet to the upper outlet. AOVHR two-pass models route oil in and out on the same side, using an internal passage to create the second cooling pass. Always verify flow direction on installation.
Lubrication & Motor Bearing Maintenance
Standard motors contain sealed, permanently lubricated ball bearings. Recommended greasing intervals for extended life:
| Operating Condition | Grease Interval |
|---|---|
| Up to ~5,000 hrs/year | Every 5 years |
| Continuous service | Every 2 years |
| Seasonal or intermittent use | Every 1 year |
| High temperature, dust, or vibration | Every 6 months |
Over-lubrication can damage bearings—follow motor manufacturer guidelines.
Viscosity Correction Factors (Cv)
Use these multipliers to adjust cooler sizing when oil viscosity or operating temperature differs from standard conditions (approximately 50 SSU leaving the cooler):
| Avg. Oil Temp (°F) | Mineral Oil (SAE) | 50/50 EG/Water | ||||
|---|---|---|---|---|---|---|
| SAE 5 | SAE 10 | SAE 20 | SAE 30 | SAE 40 | 50/50 Mix | |
| 100 | 1.14 | 1.22 | 1.35 | 1.58 | 1.77 | 1.11 |
| 150 | 1.01 | 1.05 | 1.11 | 1.21 | 1.31 | 1.02 |
| 200 | 0.99 | 1.00 | 1.01 | 1.08 | 1.10 | 0.96 |
| 250 | 0.95 | 0.98 | 0.99 | 1.00 | 1.00 | 0.95 |
Standard TEFC Motor & Fan Data
| Model | CFM | dB(A) | Motor HP | Volts | Phase | Full Load Amps | Hz | NEMA Frame | RPM | Type | Circuit | Thermal OL | Bearing |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AOVH-35 | 5921 | 89 | 3 | 208-230/460 | 3 | 9.0-8.6 / 4.3 | 60 | 182T | 1725 | TEFC | D | No | Ball |
Explosion-Proof Motor Options
Explosion-proof motors (Class I Group D; Class II Groups F & G) are available for hazardous industrial environments. Always confirm the final electrical ratings on the motor nameplate.
Frequently Asked Questions
AOVH-35 Fan-Driven Air-Oil Cooler
▶️ Question: What types of hydraulic systems typically require the cooling capacity of the AOVH-35?
Answer: The AOVH-35 is designed for heavy-duty hydraulic and lubrication systems that generate high, continuous heat loads. It is commonly used in steel and metal processing machinery, large hydraulic presses, marine systems, automated manufacturing equipment, industrial gearboxes, and high-horsepower lubrication circuits. If your system experiences chronic overheating or operates long hours under heavy load, the AOVH-35 provides the high-capacity cooling needed to stabilize oil temperature.
▶️ Question: What are the benefits of choosing the AOVHR-35-2 two-pass version?
Answer: The AOVHR-35-2 offers improved thermal performance by routing oil through the core twice, increasing heat-transfer efficiency without changing the footprint. Its built-in relief bypass valve protects the system by preventing excessive backpressure during cold starts or when using heavier oils. With a typical flow range of about 6–80 GPM, it’s ideal for demanding hydraulic and lubrication circuits requiring precise, reliable cooling under varying load conditions.
▶️ Question: What should I know about installing the AOVH-35?
Answer: Because of its large size (approx. 315 lb) and high airflow volume, the AOVH-35 must be mounted on a strong, stable horizontal surface. Maintain clear airflow to and from the finned core and leave space around the fan and motor for service access. Oil should enter the lower port and exit the upper port. Use flexible hoses to minimize vibration, and ensure the cooler is installed in a return line or dedicated cooling circuit with clean, well-filtered oil.
▶️ Question: What electrical requirements and noise levels should I expect from the AOVH-35?
Answer: The AOVH-35 uses a 3 HP TEFC fan motor, typically rated for 208–230/460 V, three-phase, 60 Hz service. With a 1725 RPM fan, it provides very high airflow and operates at approximately 89 dB(A). Ensure your facility has appropriate three-phase power and that wiring, overloads, and circuit protection are sized according to the motor nameplate.
▶️ Question: How do I maintain long-term performance on a cooler of this size?
Answer: Regular maintenance includes keeping the fins free of dust and debris, periodically inspecting electrical connections, checking the fan guard and mounting hardware, and following the motor's lubrication schedule if applicable. Ensure system oil is well-filtered to prevent fouling of the copper tubes. Monitoring temperature trends over time can help detect changes in cooling system performance before they impact equipment operation.
