Gas and electric ovens offer different advantages depending on budget, required capacity, available floor space, product geometry, and the cost of gas versus electricity.
Gas-fired convection ovens use burners to heat air within a chamber. Forced-air circulation transfers the heated air to the items being conveyed to dry, cure, or fuse the product. Direct-fired designs expose the oven air to combustion gases. Indirect-fired designs isolate combustion gases from the oven air with a heat exchanger.
An electric infrared oven, by contrast, uses infrared radiation (IR). The product surface absorbs the radiation and converts it to heat, without heating the surrounding air. Absorption depends on the match between emitter wavelength and the coating, pigment, finish, and substrate of the product.
The primary advantage of a gas convection oven is a stable, uniform temperature throughout the chamber, including around irregular product geometries. For surface heating applications, gas convection ovens can require longer dwell times, which increase oven length, capital cost, and floor space.
Gas convection ovens circulate large volumes of heated air, requiring air handling systems with motors positioned away from the hot air stream, as well as combustion exhaust systems. Fuel-fired ovens also require burner management and gas safety controls in accordance with applicable standards such as NFPA 86, and insulation to limit exterior wall temperature.
Infrared tunnel ovens do not require combustion systems and can be shorter in length where surface heating determines dwell time, since infrared radiation raises surface temperature more rapidly than heated air. Processes governed by solvent evaporation, chemical crosslinking, or heat conduction into the product require dwell times set by those process requirements in both oven types.
Vastex Industrial infrared tunnel ovens are expandable in the field by adding heating chambers and lengthening the conveyor belt, allowing increased belt speed and output where process dwell time permits.
PRODUCT GEOMETRY AND EXPOSURE
Infrared radiation travels in straight lines. Surfaces with direct exposure to the emitters receive full radiant energy, while recesses, undercuts, and vertical features receive less. Convection heats shielded surfaces through air circulation. Infrared performs best on flat or consistently oriented products such as printed substrates, film, fabrics, and coated panels.
MATERIAL ABSORPTION
Absorption of infrared energy varies with emitter wavelength and material. Testing on representative production samples confirms that an oven configuration meets process requirements.
ELECTRICAL REQUIREMENTS
Infrared ovens operate on electrical power, and larger ovens can require three-phase service. Facility electrical capacity should be confirmed during specification.
DRYING VERSUS CURING
Surface temperature can rise quickly under infrared, but solvent removal, crosslinking, and heat penetration are governed by process requirements. Dwell time and temperature profile should be validated for each product.
VENTILATION OF PROCESS EMISSIONS
Coatings, inks, adhesives, and plastics release vapors and volatile organic compounds during heating. Ventilation and safety requirements, including NFPA 86 where applicable, apply to both oven types.
UTILITY COSTS
Operating cost depends on local electricity and gas rates, as well as oven utilization. Energy consumption should be compared in kWh and BTU or therms using application-specific data.
INFRARED IS TYPICALLY SUITED TO:
GAS CONVECTION IS TYPICALLY SUITED TO:
QUESTIONS TO ANSWER BEFORE SPECIFYING AN OVEN: