SubscribePortable vented heaters may provide safety and convenience for potentially dangerous applications.
Portable vented heaters have been used for a variety of temporary heat applications in many industries over the years. With a growing concern for environmental issues and workplace safety, indirect-fired units are becoming more popular for job sites.
An indirect-fired or vented heater (vs. direct fired) contains a heat exchanger, which allows the fumes and products of combustion to be vented through a flue stack. The heat exchanger provides a barrier from the open flame, making it safer than other units in potentially dangerous areas.
A vented heater is pressurized through a fuel pump as it burns and operates with a non-pressurized tank. The result is that in certain applications and/or jurisdictions where pressurized fuel is not allowed for safety reasons, an indirect unit can be used. A safe indirect-fired heater has high limit controls, so the unit shuts down if the heat exchanger becomes too hot, and a fan switch to cool down the unit after shutdown.
As a result, an indirect-fired unit can be used in applications such as aircraft preheating, grain drying and oil field applications, where the job site has potentially dangerous combustible fumes and dust. It can be ducted directly into a tent, building, mine or other enclosed area, where other units may not meet the necessary safety and environmental standards.
According to Paul Sigurdson, President of Aerotech Herman Nelson International Inc., in Winnipeg, "Our sales of portable units have increased in recent years as customers realize a specific heating challenge can be satisfied with and indirect heater."
"Specifically indirect heaters provide clean, dry heat, which is essential in applications for accelerated drying and curing." In addition he says the design of an indirect heater allows for canvas ductwork attachments, which enhance the ability to distribute clean heated air to specific target areas.
An indirect fired unit is also proving useful in areas with extreme cold climates, he says, due to the lower freezing temperature of the fuel. Under cold conditions other units may freeze up, causing unit shutdown; an indirect unit will run where the majority of other heaters fail.
"There is a variety of applications for indirect heaters, including mining, oil fields, general construction, shipyards, railways, pulp and paper mills, farms and wherever temporary heat is required," Paul says. "With the increased price of propane and a greater awareness of this type of heater, the popularity of the indirect-fired heater should continue to grow."