Exhaust Fan Info

Because the uses for an explosion proof exhaust fan involve critical and hazardous industries that employ highly flammable and explosive chemicals, paint, glues and other explosive fumes, standard guidelines and recommendation were founded to ensure the safety of its applications.

One of the main concerns with the critical application of an explosion proof exhaust fan in these highly dangerous industrial locations where the movement of explosive gases are present is the risk of igniting these contaminants from the spark in the air stream coming from a ventilator system. Engineers and designers of an explosion proof exhaust fan take extra caution of preventing this catastrophic event to occur.

Because of these serious concerns, the Air Movement and Control Association International (AMCA) was created to develop a guideline including recommendations pertaining to the selection, construction and proper handling of air equipments used for explosive airstreams such as the explosion proof exhaust fans. The AMCA created the AMCA Standard 99-0401 Classifications on Spark Resistant Construction that involves 3 spark resistant level construction called Spark A, B, and C with the goal of ultimately avoiding the physical contact of two ferrous materials.

The Spark A, requiring that all components of the explosion proof exhaust fan should be constructed from non-ferrous materials has the highest level of spark resistance. All of the explosion proof exhaust fan air stream components are made up of aluminum in order to meet the standards imposed in the Spark A degree of spark resistant level construction.

The Spark B imposes that only the impeller should be constructed of non-ferrous materials and the air stream components of the explosion proof exhaust fans be assembled in a safe manner of avoiding physical contact between the stationary and the rotating component of the fan.

The Spark C provides the minimal spark resistance level that only imposes the reduction of the possibility of contact between the rotating and the stationary component of the explosion proof exhaust fan. Both the Spark B and C use an aluminum inlet cone as the first point of contact during a mechanical failure and an aluminum rub ring that will prevent contact between the steel fan shaft and the steel fan housing.

Choosing an explosion proof exhaust fan to use of which type of spark resistant level construction will greatly depend whether the fan will be used for hazardous or non-hazardous conditions. It would be wise to choose the Spark B and C when the application of the fan is required in less or non-hazardous conditions with Spark A or B as the right choice involving hazardous conditions.

It should be noted that most manufacturers and dealers of explosion proof exhaust fan do not recommend which type to purchase for liability reasons. It will be entirely your own choice on the unit type to buy. So choose wisely with the safety guidelines in mind to better effectively use the explosion proof exhaust fan you will purchase.

Tags: kitchen exhaust fan, attic fan, bathroom, fan, air