Electric Horizontal Airflow Cabinet Oven for Laboratory Pre-Heating and Test Preparation

The project required a compact batch oven for controlled pre-heating in a laboratory and testing-support environment. The customer operated in laboratory products and testing equipment, so the project fit a workflow where repeatable batch heating, flexible shelf loading, and dependable temperature control supported preparation work ahead of downstream handling, staging, or evaluation.

APPLICATION REQUIREMENT

• The project required a batch pre-heating oven for laboratory support work.
• The oven had to support controlled heating of samples, fixtures, containers, tools, or related work items handled in a lab or test-preparation setting.
• The process emphasized repeatability and flexible batch loading across multiple batch arrangements.

WORK CHAMBER / LOADING REQUIREMENT

• Required work chamber: 48 in W × 30 in D × 48 in H.
• The chamber had to support multi-level shelf loading for different batch arrangements.
• The final shelf package included five 100 lb capacity shelves.
• Product loading and fixturing had to preserve clear airflow paths through the chamber.

OPERATOR / ACCESS REQUIREMENT

• The oven had to allow front loading and unloading through two swing doors.
• Operators needed a layout that supported straightforward shelf access and practical batch changeover.
• The cabinet format had to fit a compact laboratory or support-area footprint.

QUALITY / CONTROL REQUIREMENT

• The process required repeatable pre-heating performance across the operating range.
• Required work-zone uniformity was ±10°F.
• The oven needed adjustable temperature control with an independent excess-temperature safety layer.

UTILITY / SITE REQUIREMENT

• Required electrical service: 208V / 3PH / 60Hz.

The project required a moderate-temperature forced-convection pre-heating process built around horizontal airflow, multi-shelf loading, and stable electric heat delivery.

TEMPERATURE REQUIREMENT

• Operating temperature range: 250°F to 350°F.
• Maximum temperature capability: 550°F.
• Required work-zone uniformity: ±10°F.

AIRFLOW / HEAT-TRANSFER REQUIREMENT

• Airflow direction: full horizontal airflow.
• The chamber air velocity was approximately 150 FPM.
• The process relied on forced-convection heating across the shelf-loaded work zone.

HEAT-INPUT REQUIREMENT

• Heat source: electric resistance heating.
• Final delivered heat on the installed electrical service: 14.7 kW.

ATMOSPHERE / VENTILATION REQUIREMENT

• The process used a Class B non-solvent heating basis.
• Fresh air entered through a fresh-air damper and exited through a gravity exhaust opening.
• The heating process centered on clean heated-air circulation for controlled pre-heating duty.

CONTROL / COOLDOWN REQUIREMENT

• The process used setpoint-based temperature control with an independent excess-temperature limit.
• Fan operation remained active through cooldown and could be ended automatically when oven temperature fell below 150°F if that function was enabled.
• The recirculation fan remained in operation until oven temperature dropped below 250°F.

To satisfy those requirements, Precision Quincy configured the project as a 40B-550 electric Class B cabinet oven with horizontal airflow, a single electric heat bank, multi-shelf loading, and side-mounted controls.

OVERALL CONCEPT

• One electric Class B cabinet oven
• Floor-standing batch configuration
• Full horizontal airflow through a shelf-loaded work chamber

HEATING ARCHITECTURE

• Heat source: electric resistance heat
• Heating package: 18 nominal 1 kW elements
• Final installed heat delivery: 14.7 kW at 208V
• Heater control architecture: solid-state relay with back-up contactor

AIRFLOW ARCHITECTURE

• Airflow pattern: full horizontal
• Recirculation fan performance: 1,500 CFM at 2 in. W.c.
• Recirculation fan motor: 1.5 HP
• Fan wheel basis: 9.94 in × 6 in

VENTILATION ARCHITECTURE

• Fresh-air damper integrated into the oven body
• 6 in square gravity exhaust opening
• Class B heated-air configuration sized for non-solvent pre-heating duty

CHAMBER / SHELL ARCHITECTURE

• Internal work chamber: 48 in W × 30 in D × 48 in H
• Wall system: 4 in thick insulated construction
• Floor system: 4 in insulated floor
• Insulation: 4 in of 6 lb mineral wool
• Interior material: unpainted aluminized steel
• Exterior finish: PQ Blue
• Control enclosure finish: ANSI 61 gray

DOOR / LOADING ARCHITECTURE

• Two swing doors
• Five 100 lb capacity shelves
• Shelf loading arranged for flexible multi-level batch placement

CONTROLS ARCHITECTURE

• SSI-804 primary temperature controller
• Gefran 650L excess-temperature controller
• 42 in × 30 in × 12 in side-mounted NEMA 1 control enclosure
• 100A non-fused disconnect switch
• Control package included recirculation fan control, heater-bank control, airflow proving, and enclosure cooling

SAFETY ARCHITECTURE

• Applicable standards basis: NFPA 79, NFPA 86, UL508A
• The control enclosure was a UL508A open industrial control panel
• Safety logic included recirculation airflow proving, excess-temperature shutdown, and heat shutdown if required operating conditions were not met
• Cooldown protection kept the fan operating until safe shutdown temperature was reached