HTF Smoke Exhaust Fan High Temperature Dual Speed Explosion Proof

The HTF dual-speed explosion-proof smoke exhaust fan is a certified fire-life-safety device that combines three functions in one unit: high-temperature smoke extraction (280°C for 2 hours), energy-efficient daily ventilation, and explosion-proof protection for hazardous locations. A two-speed motor allows low-speed operation for quiet, economical ventilation and automatic high-speed switching for maximum smoke extraction during a fire. The entire assembly carries Ex d IIB T4 certification, with a flameproof motor enclosure, non-sparking aluminum impeller, and sealed terminal box. This single fan replaces the conventional two-fan setup — one explosion-proof ventilation fan and one fire-rated smoke exhaust fan — reducing ductwork, controls, and maintenance. Available from 3,000 to 30,000 m³/h against static pressures up to 800 Pa, it is the specified smoke control device for chemical plants, paint shops, refineries, and any facility requiring both explosion protection and certified fire smoke exhaust.

A standard fire-rated smoke fan lacks explosion-proof certification, creating ignition risk during normal operation in hazardous areas. A standard explosion-proof fan lacks high-temperature rating and fails within minutes of a fire. Facility operators are forced to install two separate fan systems, doubling installation and maintenance costs.

The dual-speed flameproof motor runs at low speed for daily ventilation with minimal noise and energy. On receiving a fire alarm signal, it automatically switches to high speed for smoke extraction. The motor, bearings, casing, and seals withstand 280°C for 2 hours. The flameproof enclosure and non-sparking impeller maintain explosion-proof integrity at all conditions. High-temperature seals and vibration isolators ensure no material failure during a fire.

• Chemical plants: hazardous-area ventilation and fire smoke exhaust.
• Paint spray booths and solvent storage: combined dilution ventilation and emergency extraction.
• Petroleum refineries and fuel depots.
• Grain and feed mills with combustible dust.
• Underground car parks with explosion-risk classification.
• Any Zone 1 or Zone 2 hazardous area requiring dedicated fire smoke exhaust.

The motor runs at low speed for daily ventilation. Upon fire alarm activation, the control panel automatically switches to high speed. The impeller and casing maintain mechanical integrity at 280°C. The flameproof enclosure prevents internal sparks from reaching the external atmosphere. The fan continues extracting smoke for the full rated duration.

1. Determine smoke exhaust airflow and verify it meets daily ventilation needs at low speed.
2. Identify gas group: Ex d IIB T4 for standard solvents and fuels; Ex d IIC T4 for hydrogen or acetylene.
3. Confirm electrical supply and specify a fire-rated control panel with automatic speed switching.
4. Verify that connected ductwork is also fire-rated and explosion-proof per local codes.
5. Contact our engineers with building dimensions, zone classification, and fire safety requirements for certified selection within 24 hours.