Frequently Asked
Questions

We manufacture DC axial fans across a wide range of frame sizes, from compact 25mm units up to large 254mm industrial fans, covering standard series such as HR2510, HR4020, HR6025, HR8025, HR9225, HR9238 and HR1238. Custom frame sizes can also be discussed for OEM projects.

Our DC axial fans are available in standard voltages of 5V, 12V, 24V and 48V. Most series support a wide operating voltage range (for example 10.8–13.2V for a nominal 12V fan) to stay compatible with typical DC power fluctuations in the field.

HD (High-speed), MD (Medium-speed) and LD (Low-speed) are pre-set speed variants of the same physical fan model. HD delivers the highest airflow and static pressure at a higher noise level, LD runs quieter with reduced airflow, and MD sits in between. This lets you pick the performance/noise balance that fits your system without changing the fan footprint.

We offer sleeve bearing, ball bearing and dual ball bearing options depending on the series. Ball bearing and dual ball bearing versions are generally recommended for high-temperature, high-altitude, or continuous 24/7 operation, while sleeve bearing is a cost-effective choice for standard horizontal-mount applications.

Typical L10 life ranges from around 40,000 hours for sleeve bearing models to 70,000–100,000+ hours for ball bearing and dual ball bearing models at rated temperature. Actual lifespan depends on ambient temperature, orientation and duty cycle — our team can advise on the right bearing type for your operating environment.

Standard fans are rated IP20–IP22. For harsher environments we offer IP54 and IP55 sealed versions with protected PCB and cable entry, suitable for outdoor cabinets, telecom equipment and industrial machinery exposed to dust or splashing water.

Yes. Beyond selecting an existing HD/MD/LD variant, we can adjust blade angle, motor winding and speed curve to tune CFM and static pressure for your specific enclosure. Share your target airflow, back pressure and available space, and our engineers will recommend or design a matching option.

A free-air CFM number only tells you how much air the fan moves with nothing in its way. Once it’s pushing air through a filter, heat sink, narrow duct, or a tightly packed enclosure, static pressure — not free-air CFM — determines real performance. Two fans with identical CFM ratings can have very different static pressure curves, so the one with lower static pressure will lose much more airflow under resistance. Share your enclosure’s actual airflow path (filters, ducting, obstructions) and we can recommend a fan matched to your real back pressure, not just the datasheet’s best-case number.

MOQ typically starts at 500–1,000 pieces per model for standard catalog products. For OEM/ODM or custom-spec fans, MOQ is usually higher and depends on the complexity of the customization — please contact us with your target model and quantity for an exact figure.

We can usually provide samples for evaluation; sample cost and whether it is waived depends on the model and quantity requested. Freight for samples is normally covered by the buyer unless otherwise agreed.

Standard catalog models typically ship within 15–25 days after order confirmation, depending on order size. Custom or OEM orders usually require 30–45 days to allow for tooling, testing and quality checks. Exact lead time is confirmed at the time of order.

We accept T/T (bank transfer) as the primary payment method, typically with a deposit before production and balance before shipment. L/C at sight can be arranged for larger orders upon request — let us know your preferred terms when requesting a quotation.

Yes, for many series we can combine multiple models, voltages or speed variants within the same production run to help you reach MOQ, as long as the total quantity meets our minimum production threshold. Ask your sales contact to confirm which models can be combined.

Yes, pricing is tiered based on order quantity, with better unit pricing at higher volumes. Send us your target annual or per-order quantity and we will provide a volume-based quotation.

Send us the model number (or your target specifications: size, voltage, airflow, static pressure, noise level), required quantity, and destination port. Our team will reply with pricing, lead time and available certifications within 1–2 business days.

Final inspection isn’t the only checkpoint. Incoming materials (motors, bearings, blades, PCBs) are inspected before they enter production, in-process spot checks are done at key assembly stages, and every unit undergoes 100% functional testing (rotation, current draw, and where applicable RPM/noise) before packing. This layered approach catches issues earlier than relying on final inspection alone.

We support sea freight (FCL/LCL) for bulk orders, air freight for urgent or smaller shipments, and express courier (DHL, FedEx, UPS) for samples and small parcels. We can recommend the most cost-effective option based on your order size and timeline.

We commonly work with EXW, FOB and CIF. DDP can also be arranged for certain destinations upon request. Please specify your preferred incoterm when requesting a quotation so pricing is accurate.

Fans are individually packed in anti-static bags, then boxed in export cartons with corner protection, and palletized with shrink-wrap for sea/air freight. Custom packaging (retail boxes, OEM labeling) is available for OEM orders.

Yes, we regularly ship to freight forwarders’ warehouses in Shenzhen, Guangzhou, Ningbo, Shanghai and other major hubs. Just provide your forwarder’s contact details and delivery instructions when placing the order.

By sea freight, transit time is roughly 25–35 days to North America and Europe, and 15–20 days to Southeast Asia, depending on the port and shipping line. Air freight typically takes 5–10 days door-to-door. These are estimates — actual transit time depends on the carrier and customs clearance.

Yes, once your order ships we provide the bill of lading (B/L) or air waybill (AWB) number, along with carrier and tracking details, so you can monitor the shipment’s progress.

We provide commercial invoice, packing list, and certificate of origin as standard. Product certificates (CE, RoHS, etc.) and other documents needed for customs clearance in your country can be provided on request — let us know your import requirements in advance.

Yes, we offer OEM services including custom fan labels, custom color packaging, and branded cartons. This is available for orders meeting our OEM MOQ — contact us with your branding requirements and target quantity.

Yes. With 30+ years of DC axial fan engineering experience, our team can design a fan to match your specific dimensional, performance, connector, or environmental requirements. Share your application details and target specifications to start the ODM discussion.

OEM/ODM MOQ is generally higher than standard catalog products, as it depends on tooling and design complexity. We will confirm the exact MOQ once your specifications are finalized.

Yes, we are open to signing a mutual NDA before reviewing detailed specifications for custom or sensitive projects. Please let us know if you require one before sharing your design documents.

In most cases we can engineer a fan to match or closely replicate the dimensional footprint, airflow, static pressure, and connector type of a reference fan. Send us the reference model number or datasheet and we will confirm feasibility.

Depending on complexity, custom development from initial design to first sample typically takes 3–6 weeks, followed by sample validation and any design iteration before mass production tooling is finalized.

Yes, our engineering team can support you with thermal/airflow calculations, mounting and connector recommendations, and troubleshooting during your product integration and validation phase.

Core manufacturing — motor winding, blade molding, and final assembly — is done in-house so we can control quality and lead time directly. Certain standard components (bearings, connectors) may be sourced from qualified component suppliers, which is standard industry practice. If full in-house production of every component is a requirement for your project, let us know and we’ll confirm exactly what’s in-house vs. sourced for your specific model.

Axial fans move air parallel to the motor shaft and are best for open-path airflow with low to medium resistance, such as ventilating an enclosure. Blower (centrifugal) fans generate higher static pressure and are better suited for pushing air through ducts, filters, or tightly packed components. Tell us your airflow path and resistance and we can recommend the right type.

These codes represent optional motor protection and control functions: for example RD (rotation direction), FG (tachometer/speed feedback signal), PPWM (PWM speed control input), and similar codes for locked-rotor protection, alarm signal, and voltage-based speed control. Each product page lists which functions are supported so you can match them to your control system.

Noise is measured at rated voltage in a semi-anechoic chamber at a 1-meter distance from the fan’s air intake, following standard industry test methods. Published dB(A) values in our datasheets reflect this standardized measurement condition.

Standard fans typically operate from -10°C to 70°C. Extended-temperature versions (down to -40°C or up to 85°C) are available for harsh industrial, outdoor, or automotive-adjacent environments — let us know your ambient temperature range when selecting a model.

A common starting formula is CFM = (Watts to dissipate × 3.16) ÷ (allowable temperature rise in °F), adjusted for altitude and any airflow resistance in your enclosure. Send us your heat load and temperature rise target and our team can help size the right fan.

PWM (pulse-width modulation) speed control keeps the fan running at full voltage but varies the duty cycle of the drive signal, giving more precise and efficient speed control at low speeds. Voltage control simply reduces the supply voltage to slow the fan, which is simpler but less efficient and can affect starting torque at low voltages.

Yes, locked-rotor protection (LR) is available as an optional function on most series. It automatically stops and restarts the motor if the impeller is obstructed, preventing motor burnout. Check the available functions table on each product page to confirm support for your model.

Often, yes. A rising whine or a rough, irregular sound (as opposed to steady airflow noise) is usually the earliest sign of bearing wear, well before the fan actually stops. On sleeve bearing fans this is typically lubricant depletion; on ball bearing fans it’s usually raceway wear. Catching this early and swapping the fan is far cheaper than dealing with an unplanned shutdown once the bearing fails completely. If you’re seeing this across a batch of fans earlier than expected, let us know the model and operating conditions so we can investigate.

It can, especially for sleeve bearing fans. Sleeve bearings rely on lubricant staying evenly distributed around the shaft; in a vertical mount, gravity can pull the lubricant to one side over time, leading to faster wear and a shorter effective life than the horizontal-mount rating on the datasheet. Ball bearing and dual ball bearing fans are far less sensitive to orientation and are the safer choice if your application requires vertical mounting.

Depending on the series, our fans carry certifications including CE, RoHS, and UL/CUL recognition, with some models also available with FCC and REACH compliance. Certification coverage varies by model — check the specific product page or ask our team to confirm for your target model.

Yes, we can provide copies of relevant product certificates (CE, RoHS, UL, etc.) along with the commercial shipping documents to support customs clearance in your country.

Yes, we accept third-party pre-shipment inspections (such as SGS or similar agencies) arranged by the buyer. Please coordinate inspection scheduling with our team once production is nearing completion.

REACH compliance is available for applicable models — please confirm the specific model you need so we can provide the relevant REACH declaration or test report.

Yes, we can issue a Declaration of Conformity (DoC) referencing the applicable certifications for your ordered model, which can support your own product’s regulatory documentation.

Factory audit reports and facility information can be shared upon request, and we also welcome qualified buyers to arrange a factory audit before finalizing large orders.

Our production follows ISO 9001 quality management principles, with incoming material inspection, in-process quality control, and 100% functional testing before packing to ensure consistent performance across every batch.

Herays is a DC axial fan manufacturer led by an engineering team with over 30 years of combined experience in DC fan design and production, based in China. We focus specifically on DC axial and blower fans for industrial and B2B applications.

Yes, qualified customers are welcome to visit our factory by appointment. Please contact our sales team in advance to schedule a visit and arrange any necessary details.

We offer a standard warranty covering manufacturing defects under normal use conditions; specific warranty duration can vary by product series. Please confirm warranty terms with our sales team for your selected model.

You can reach our technical team directly via email or WhatsApp for troubleshooting, replacement parts, or application questions after your purchase. We aim to respond to technical inquiries within 1 business day.

Yes, our sales and technical support team communicates fluently in English and regularly works with international B2B customers across different time zones.

Our fans are used across telecom equipment, server and data center cooling, industrial machinery, power supplies, LED lighting, medical devices, and other applications requiring reliable forced-air cooling.

Send us the model number, or describe your application and required specifications, and our team will send the corresponding datasheet (PDF) with full dimensional drawings and performance curves.

Fair question, and one every overseas buyer should ask before committing to a supplier. We welcome factory audits (in-person or via video call), can share our export license and production line details, and are happy to walk you through our manufacturing process for the specific model you’re evaluating. If a supplier is reluctant to answer this directly or show their production floor, that’s usually a sign they’re a trading company rather than the manufacturer.

Yes, where confidentiality agreements allow. We can share the industries and application types we commonly supply (telecom, data center, industrial machinery, etc.) and, where a reference customer has agreed to be cited, connect you with relevant case examples. Let us know your industry and target application so we can point you to the most relevant experience.