An effective industrial fan RFQ checklist should define the required airflow, pressure, operating conditions, construction, motor, documentation, delivery terms and acceptance requirements. The more precisely these details are stated, the easier it is to compare quotations and avoid receiving fans that cannot meet the actual system duty.
A quotation should be evaluated as a complete equipment package, not only by fan size or purchase price. Use the following checklist to prepare the request and identify gaps before issuing a purchase order.
Define the Duty Point and Operating Conditions
The duty point is the starting point for every industrial fan RFQ. Suppliers need to know the airflow and pressure the fan must produce at the actual operating condition. A request that says only “high-volume exhaust fan” or “industrial blower” leaves too much room for interpretation.
State the required airflow in a clear unit, such as m³/h, m³/s or CFM. Then specify the required pressure and whether it is static pressure, total pressure or a pressure difference across the fan. These values should be tied to the design airflow. For a useful explanation of the main performance terms, see Fan Technical Specs Explained: Airflow, Static Pressure and Power.
Include the following duty information in the RFQ:
- Design airflow and any minimum or maximum airflow requirement
- Required static pressure or total pressure at the design airflow
- System resistance, including filters, coils, silencers, dampers, ductwork and terminals
- Inlet and outlet pressure conditions, if the fan is part of a pressurized process
- Continuous, intermittent or variable-speed operation
- Required operating range and control method
- Air density, elevation and expected temperature
- Gas composition, humidity, dust loading or corrosive contaminants
- Required sound limit, if noise is controlled by the project specification
Air density changes with temperature, altitude and gas composition. A fan selected for standard air may deliver different mass flow, pressure and motor load at a hot process temperature or elevated site. Provide the normal, minimum and maximum operating temperatures where they could affect selection. This is especially important for roof exhaust, combustion air, drying systems and high-temperature process ventilation. See Fan Selection at Altitude and Temperature: Correcting for Air Density for additional selection context.
If the system has not been fully calculated, say so in the RFQ and identify the assumptions. Ask suppliers to state the duty point they used for selection rather than allowing each bidder to choose a different interpretation.
List Fan, Motor and Mounting Requirements
Once the duty is defined, describe the equipment configuration and installation constraints. A fan can meet the airflow requirement and still be unusable because the rotation, discharge position, motor arrangement or connection dimensions are wrong.
Specify the fan type or state that the supplier may propose an alternative. Common choices include forward-curved or backward-curved centrifugal fans, belt-driven centrifugal fans, plug fans, mixed-flow fans and axial fans. If you are uncertain which category is suitable, compare the pressure, space and maintenance implications in Centrifugal Fan vs Axial Fan: How to Choose.
Request the following fan data:
- Fan model, series and nominal size
- Impeller type, diameter and number of blades
- Rotation direction, viewed from the specified side
- Discharge angle or outlet orientation
- Inlet and outlet dimensions and flange details
- Mounting position and base or bracket arrangement
- Direct-drive, belt-drive or other transmission arrangement
- Design speed and permissible speed range
- Impeller material and balancing information
- Bearing type, bearing location and expected maintenance access
- Approximate operating weight and lifting points
- Noise data and vibration limits, when required
Motor specifications must be listed separately from fan specifications. State the required power supply, including phase, voltage, frequency and allowable voltage variation. Identify the motor efficiency requirement, enclosure or ingress protection level, insulation class, starting method and control arrangement.
Also request motor rated power, rated current, speed, service factor where applicable, terminal box position and mounting details. For variable-frequency-drive operation, confirm that the motor and fan are suitable for the proposed speed range. Ask the supplier to identify any minimum speed, maximum speed, resonance or cooling limitation.
A basic RFQ motor table can use this format:
| Item | Buyer requirement | Supplier response |
|---|---|---|
| Supply | Example: 3-phase, 400 V, 50 Hz | State exact motor supply |
| Rated power | State required or ask supplier to select | kW and margin used |
| Speed control | Fixed speed, inverter or EC control | Control method and range |
| Protection | Project or site requirement | Enclosure rating and details |
| Starting | Direct, soft start or inverter | Starting current or method |
| Motor location | Integrated, external or remote | Mounting arrangement |
| Compliance | Project-specific requirements | Standards and documents supplied |
Do not assume a fan with the same nominal diameter will fit an existing installation. Request certified or dimensioned drawings showing overall length, width, height, shaft position, flange dimensions, access panels, motor clearance and service space. For replacement work, provide photographs and measurements of the existing unit. The guide Industrial Fan Replacement: How to Match the Right Unit covers the dimensions and operating data that should be checked.
Request Drawings, Curves and Test Documentation
A complete quotation should show how the proposed fan meets the duty point. Ask for a fan performance curve covering the requested airflow and pressure, with the operating point clearly marked. The curve should identify the test basis, air density or correction condition, rotational speed and power information.
Request these technical documents with the offer or before order confirmation:
- General arrangement drawing with principal dimensions
- Performance curve showing airflow, pressure, efficiency and power
- Motor data sheet and wiring diagram
- Fan outline and mounting drawing
- Rotation and discharge orientation drawing
- Installation, operation and maintenance instructions
- Recommended spare parts list
- Noise and vibration data, where relevant
- Material and coating description
- Factory inspection or test plan, if required by the project
- Balancing record or certificate, when specified
- Declaration or compliance documents required for the destination market
Check whether the stated pressure is static or total. These terms are not interchangeable. Confirm whether the fan curve includes inlet and outlet losses, and ask how the supplier defines the test point. A curve without units, speed, density or power data is difficult to use for a purchasing decision.
Ask the supplier to state the expected operating point at the actual system resistance. The duty point should not be shown only as a maximum airflow or maximum pressure value. Maximum values often occur at different conditions and do not prove that the fan can meet both requirements simultaneously.
For systems with complex duct transitions, elbows near the inlet, dampers or restricted outlets, include the installation arrangement in the RFQ. Ductwork can change the airflow distribution entering the impeller and increase system resistance. Fan System Effect: How Ductwork Changes Fan Performance explains why the equipment selection should reflect the real installation rather than an ideal test setup.
If acceptance testing is important, define it before ordering. State the measurement method, test instruments, tolerances, test location and responsibility for field verification. Factory test data and installed field performance are related but not identical. A field commissioning plan may be needed to confirm actual airflow and pressure after ductwork, filters and dampers are connected.
Specify Materials, Accessories and Export Packing
Material requirements should reflect the air or gas being handled and the environment around the fan. State whether the fan will handle clean air, dust, moisture, oil mist, salt-laden air, chemical vapor, abrasive particles or high-temperature gas.
Specify the required materials for the casing, impeller, shaft, frame, fasteners and guards. If corrosion resistance is needed, define the preferred material or performance requirement instead of using only the phrase “anti-corrosion.” Coatings differ in surface preparation, thickness and chemical resistance. See Corrosion-Resistant Fans: Choosing Between PP, FRP, Stainless Steel and Coatings when comparing construction options.
Include accessories in the RFQ so suppliers quote the same scope. Depending on the installation, these may include:
- Flexible connectors and vibration isolators
- Inlet or outlet guards
- Dampers, louvers and backdraft shutters
- Inspection doors and drain points
- Belt guards and spare belts
- Weather hoods or roof curbs
- Silencers or acoustic enclosures
- Inlet cones, filters or screens
- Vibration switches and temperature sensors
- Local isolators, control panels or speed controllers
- Lifting lugs and maintenance platforms
For hazardous locations, identify the area classification, gas or dust group, temperature class and required equipment approval. Do not ask for a generic “explosion-proof fan” without describing the hazard and the applicable project requirements. The supplier should confirm the complete fan and motor arrangement, not only the motor designation. Review Explosion-Proof Fan Selection for Hazardous Areas before finalizing the RFQ.
Export packing also belongs in the technical scope. State the destination, transport mode, expected storage period and whether the cargo may be exposed to rain, salt air or repeated handling. Ask the supplier to identify:
- Crate or pallet construction
- Moisture protection and desiccant use
- Internal bracing for impellers and motors
- Corrosion protection for exposed machined surfaces
- Marking, package numbers and gross dimensions
- Net and gross weight
- Lifting points and center-of-gravity markings
- Packing list and shipping documentation
Confirm whether accessories are packed with the main fan or shipped separately. Missing guards, fasteners, sensors or transition pieces can delay installation even when the main equipment arrives on time.
Compare Lead Time, Warranty and Total Quotation Scope
A lower equipment price may not represent a lower project cost. Compare quotations line by line and record exclusions. Suppliers may quote the fan only while another supplier includes the motor, base, controls, flexible connections and export packing.
Use a comparison sheet with at least these categories:
| Comparison category | Questions to verify |
|---|---|
| Technical compliance | Does the fan meet the stated airflow and pressure at the same density and speed? |
| Motor scope | Is the motor included, correctly rated and suitable for the stated power supply? |
| Accessories | Are guards, dampers, isolators, connectors and controls included or excluded? |
| Documentation | Are drawings, curves, manuals, test records and compliance documents supplied? |
| Delivery | Is the lead time based on order date, drawing approval or payment receipt? |
| Packing | Is export packing included, and are package dimensions and weights stated? |
| Warranty | What is covered, for how long and from which date does coverage begin? |
| Commercial terms | Are taxes, freight, insurance, duties and local charges included or excluded? |
Ask for the production lead time, drawing approval period, inspection period and estimated transit time separately. A stated lead time may begin only after technical approval, deposit receipt or receipt of all required data. The purchase order should define the trigger clearly.
Warranty terms should explain coverage for the fan, motor, bearings, controls and accessories. Check exclusions related to incorrect installation, operation outside the duty range, poor maintenance, voltage variation, corrosion and unauthorized modifications. Also ask how replacement parts and technical support are handled during the warranty period.
For rotating equipment, request the recommended commissioning procedure and maintenance schedule. Bearings, belts, fasteners, alignment and vibration should be checked during installation and operation. A quotation that includes only a warranty statement but no maintenance requirements leaves important operating assumptions undocumented.
Check the Quotation Before Placing the Purchase Order
Before issuing the purchase order, reconcile the RFQ, supplier offer, approved drawing and final commercial terms. Do not rely on a general statement such as “as requested” when critical specifications are involved.
Use this final review sequence:
- Confirm the airflow, pressure, air density, temperature and operating point on the final quotation.
- Confirm fan rotation, discharge direction, inlet and outlet dimensions, mounting arrangement and service clearances.
- Confirm motor voltage, frequency, phase, power, speed, protection, control method and cable entry details.
- Check the performance curve and verify that the selected point is within a practical operating range, not at an unstable or maximum limit.
- Match all accessories, spare parts, sensors, guards and controls against the equipment schedule.
- Review materials, coatings, fasteners and special construction requirements against the process conditions.
- Confirm drawings, manuals, test records, balancing documents and compliance paperwork included in the document schedule.
- Verify packing type, package dimensions, weights, shipping marks and delivery responsibility.
- Record the agreed lead time, inspection requirements, warranty terms, payment terms and quotation validity.
- Ask the supplier to list every deviation, assumption and exclusion in writing before order release.
The final purchase order should reference the approved technical specification and drawing revision. Any later change to airflow, pressure, temperature, motor, material or discharge orientation should go through documented technical approval. This prevents an informal email or revised quotation from creating an unrecognized change in scope.
A well-prepared industrial fan RFQ makes supplier comparison more objective. It also gives the manufacturer enough information to select the correct fan, motor and accessories for the real installation. When technical data is incomplete, request clarification before comparing prices rather than treating different assumptions as equivalent offers.
FAQ
What is the most important information in an industrial fan RFQ?
The most important information is the required airflow and pressure at a defined operating condition. Include air density, temperature, altitude, gas composition and system resistance when they can affect fan performance or motor power.
Should buyers request a fan curve with every quotation?
Yes. Request a curve showing airflow, pressure, speed, power and efficiency, with the proposed duty point marked. Also confirm whether the pressure is static or total and what air density was used.
What motor details should be included in the RFQ?
Specify phase, voltage, frequency, rated power, speed, protection level, insulation class, starting method and speed-control requirements. State whether the motor is included and whether it will operate with an inverter or other controller.
How can buyers compare quotations that use different fan models?
Compare the models at the same airflow, pressure, density, speed and installation condition. Then compare motor power, efficiency, noise, vibration, materials, accessories, documentation, delivery scope and warranty instead of comparing model names or fan diameter alone.
What should be done if the existing fan has no readable nameplate?
Record the existing dimensions, rotation, discharge direction, motor supply, duct sizes and measured operating conditions. Photographs, motor data, system drawings and field airflow measurements can help the supplier identify a suitable replacement, but the final selection should be checked against the required duty point.
Request an Industrial Fan Quotation Review
Send your required airflow and pressure, operating temperature, air or gas conditions, power supply, installation drawing and quantity through our contact form. Include the required delivery destination and any project documentation requirements. Ask the quotation team to confirm the proposed model, available performance records, included accessories and commercial scope before placing an order.