Skip to content
Home / News / Wok Hei: The Physics of Wok Cooking Emissions and ESP Capture Efficiency
May 20, 2026

Wok Hei: The Physics of Wok Cooking Emissions and ESP Capture Efficiency

Deep technical dive into the physics of wok hei emissions: particle size distribution, grease aerosol chemistry, and how ESP is engineered for the unique emission profile of high-heat Chinese wok cooking.

Wok Hei: The Physics of Wok Cooking Emissions and ESP Capture Efficiency

Wok cooking generates one of the most challenging emission profiles. Wok hei describes the complex combination of smoke, vapor, and aerosolized oil produced by ingredients hitting a superheated wok at 200-300C. Understanding the physics is essential for effective purification design.

Parameter Specification
Wok Emission Profile Temp: 200-300C at wok surface; Bimodal particle size: coarse mode (2-10 um oil droplets) and fine mode (0.05-0.5 um condensation nuclei); Contains PAHs, aldehydes, fatty acids
ESP Engineering for Wok Dual-zone ESP: first zone captures coarse mode with 10mm plate spacing; second zone captures fine mode with 6mm spacing; Higher voltage for fine particles; Corrosion-resistant tungsten wires
Capture Volume Design 30-50% more capture volume than Western cooking; Thermal plume velocity 0.5-1.0 m/s at hood lip; Minimum capture 0.3 m/s at furthest wok point
Souniny Wok Models Heavy-duty Series standard (2-4 woks); Heavy-duty Series high-volume (4-8 woks); Light-duty Series single wok premium

Application Scenarios

  • Hong Kong PolyU research: Detailed particle analysis found bimodal distribution peaking at 0.3 um and 5 um. Standard single-zone ESP captures 60% of fine mode. Dual-zone captures 95%+ of both modes. Published in Atmospheric Environment.
  • Dai pai dong modernization (Hong Kong): Famous 40-year dai pai dong known for best wok hei installed Heavy-duty Series. Chef initially skeptical: Wok hei needs the smoke. Revised: Flavor in food, not air. But now my lungs do not hurt. Business increased.
  • China MEE emission standards: Souniny ESP data submitted to Ministry of Ecology and Environment technical working group. Demonstrated dual-zone ESP achieves over 95% PM2.5 removal. Draft standard would require over 90% removal in urban areas.
  • CFD optimization study: Optimized hood design achieves 98% capture at 20% lower airflow than traditional — significant energy saving. Incorporated into Souniny design guidelines for Chinese cuisine.
SOUNINY Application Engineering Team
SOUNINY Application Engineering Team
Commercial Kitchen Ventilation Specialists

A multidisciplinary team of application engineers and kitchen-ventilation specialists at Shenzhen Shuangni Environmental Technology Co., Ltd. (SOUNINY). We design, test and deploy grease, smoke and odor-control systems for restaurants, hotels, food factories and ghost kitchens across 30+ countries, and author the technical guidance published on this site.

← Back to News Request a Solution

Need Help Choosing?

Tell us your kitchen type, required airflow and target market — we'll recommend the right model and send a tailored quote.

Email: info@souniny.com
Scroll to Top