🔥 Get Full Catalog

Buying from LONGWELL

  • Brand owner since 1990
  • Yuyao, Ningbo
  • 12-month standard warranty, extendable to 18–24 months by project agreement
  • Reply within 1 business day

Certificates you can check

Product certificates cover only the models listed on each document — ask which ones apply to your model. ISO certificates cover management systems, not products. Declaration of Conformity for your model and destination on request.

All document scans and what each covers

Test & release at LONGWELL

Specified and drawn by LONGWELL, built to our drawings by qualified partner factories, inspected and released to LONGWELL standards.

  • Wind tunnel · AMCA 210 method
  • Semi-anechoic room · sound power testing
  • Outgoing sampling to AQL 2.5
  • Test records retained for 5 years

How ordering works

  1. Spec check duty point & drawings
  2. Samples 1–3 days (stock models), fee credited to first order
  3. Validation on your bench
  4. Order T/T 30/70 (first order)
  5. Production & release 15–30 days, partner factory
  6. Shipping & after-sales FOB · CIF · DDP
Full terms, QC and FAQ
Current book for Speed Regulator

Speed Regulator

Longwell Speed Regulators are designed to adjust fan and motor speeds for optimized performance and energy efficiency. They allow smooth control of airflow, noise, and power consumption across ventilation and HVAC applications.
Using advanced electronic control circuits, Longwell regulators provide precise output with stable operation. Compact and easy to install, they are compatible with both AC and DC motors for flexible system integration.