PERMIT TO INSTALL. Table of Contents

Permit No. 78-15D Page 1 of 50 PERMIT TO INSTALL Table of Contents Section Page Alphabetical Listing of Common Abbreviations / Acronyms... 2 General Conditions... 3 Special Conditions... 5 Emission Unit Summary Table... 5 Special Conditions for EU-ChipDryer... 8 Special Conditions for EU-MoldPreHeat... 12 Special Conditions for EU-MoldCoatFurn... 14 Special Conditions for EU-MoldSonicClean... 16 Special Conditions for EU-DieCasting... 17 Special Conditions for EU-SandBlast... 19 Special Conditions for EU-Pretreatment... 21 Special Conditions for EU-PretreatOven... 23 Special Conditions for EU-PaintShopBlr... 25 Special Conditions for EU-LiquidCoat... 27 Special Conditions for EU-BrushingBurr... 32 Special Conditions for EU-Gen1... 34 Flexible Group Summary Table... 38 Special Conditions for FG-Melting... 39 Special Conditions for FG-HeatTreat... 43 Special Conditions for FG-PowderCoat... 45 Special Conditions for FG-MACT6Z... 47 Special Conditions for FGFACILITY... 49

Permit No. 78-15D Page 2 of 50 Common Abbreviations / Acronyms Common Acronyms Pollutant / Measurement Abbreviations AQD Air Quality Division acfm Actual cubic feet per minute BACT Best Available Control Technology BTU British Thermal Unit CAA Clean Air Act C Degrees Celsius CAM Compliance Assurance Monitoring CO Carbon Monoxide CEM Continuous Emission Monitoring CO 2 e Carbon Dioxide Equivalent CFR Code of Federal Regulations dscf Dry standard cubic foot COM Continuous Opacity Monitoring dscm Dry standard cubic meter Department/ Michigan Department of Environmental F Degrees Fahrenheit department Quality gr Grains EU Emission Unit HAP Hazardous Air Pollutant FG Flexible Group Hg Mercury GACS Gallons of Applied Coating Solids hr Hour GC General Condition HP Horsepower GHGs Greenhouse Gases H 2 S Hydrogen Sulfide HVLP High Volume Low Pressure* kw Kilowatt ID Identification lb Pound IRSL Initial Risk Screening Level m Meter ITSL Initial Threshold Screening Level mg Milligram LAER Lowest Achievable Emission Rate mm Millimeter MACT Maximum Achievable Control Technology MM Million MAERS Michigan Air Emissions Reporting System MW Megawatts MAP Malfunction Abatement Plan NMOC Non-methane Organic Compounds MDEQ Michigan Department of Environmental NO x Oxides of Nitrogen Quality ng Nanogram MSDS Material Safety Data Sheet PM Particulate Matter Not Applicable Particulate Matter equal to or less than 10 PM10 AQS National Ambient Air Quality Standards microns in diameter NESHAP National Emission Standard for Hazardous Particulate Matter equal to or less than 2.5 Air Pollutants PM2.5 microns in diameter NSPS New Source Performance Standards pph Pounds per hour NSR New Source Review ppm Parts per million PS Performance Specification ppmv Parts per million by volume PSD Prevention of Significant Deterioration ppmw Parts per million by weight PTE Permanent Total Enclosure psia Pounds per square inch absolute PTI Permit to Install psig Pounds per square inch gauge RACT Reasonable Available Control Technology scf Standard cubic feet ROP Renewable Operating Permit sec Seconds SC Special Condition SO 2 Sulfur Dioxide SCR Selective Catalytic Reduction TAC Toxic Air Contaminant SNCR Selective Non-Catalytic Reduction Temp Temperature SRN State Registration Number THC Total Hydrocarbons TEQ Toxicity Equivalence Quotient tpy Tons per year USEPA/EPA United States Environmental Protection µg Microgram Agency µm Micrometer or Micron VE Visible Emissions VOC Volatile Organic Compounds yr Year *For HVLP applicators, the pressure measured at the gun air cap shall not exceed 10 psig.

Permit No. 78-15D Page 3 of 50 GENERAL CONDITIONS 1. The process or process equipment covered by this permit shall not be reconstructed, relocated, or modified, unless a Permit to Install authorizing such action is issued by the Department, except to the extent such action is exempt from the Permit to Install requirements by any applicable rule. (R 336.1201(1)) 2. If the installation, construction, reconstruction, relocation, or modification of the equipment for which this permit has been approved has not commenced within 18 months, or has been interrupted for 18 months, this permit shall become void unless otherwise authorized by the Department. Furthermore, the permittee or the designated authorized agent shall notify the Department via the Supervisor, Permit Section, Air Quality Division, Michigan Department of Environmental Quality, P.O. Box 30260, Lansing, Michigan 48909-7760, if it is decided not to pursue the installation, construction, reconstruction, relocation, or modification of the equipment allowed by this Permit to Install. (R 336.1201(4)) 3. If this Permit to Install is issued for a process or process equipment located at a stationary source that is not subject to the Renewable Operating Permit program requirements pursuant to R 336.1210, operation of the process or process equipment is allowed by this permit if the equipment performs in accordance with the terms and conditions of this Permit to Install. (R 336.1201(6)(b)) 4. The Department may, after notice and opportunity for a hearing, revoke this Permit to Install if evidence indicates the process or process equipment is not performing in accordance with the terms and conditions of this permit or is violating the Department s rules or the Clean Air Act. (R 336.1201(8), Section 5510 of Act 451, PA 1994) 5. The terms and conditions of this Permit to Install shall apply to any person or legal entity that now or hereafter owns or operates the process or process equipment at the location authorized by this Permit to Install. If the new owner or operator submits a written request to the Department pursuant to R 336.1219 and the Department approves the request, this permit will be amended to reflect the change of ownership or operational control. The request must include all of the information required by subrules (1)(a), (b), and (c) of R 336.1219 and shall be sent to the District Supervisor, Air Quality Division, Michigan Department of Environmental Quality. (R 336.1219) 6. Operation of this equipment shall not result in the emission of an air contaminant which causes injurious effects to human health or safety, animal life, plant life of significant economic value, or property, or which causes unreasonable interference with the comfortable enjoyment of life and property. (R 336.1901) 7. The permittee shall provide notice of an abnormal condition, start-up, shutdown, or malfunction that results in emissions of a hazardous or toxic air pollutant which continue for more than one hour in excess of any applicable standard or limitation, or emissions of any air contaminant continuing for more than two hours in excess of an applicable standard or limitation, as required in Rule 912, to the Department. The notice shall be provided not later than two business days after start-up, shutdown, or discovery of the abnormal condition or malfunction. Written reports, if required, must be filed with the Department within 10 days after the start-up or shutdown occurred, within 10 days after the abnormal conditions or malfunction has been corrected, or within 30 days of discovery of the abnormal condition or malfunction, whichever is first. The written reports shall include all of the information required in Rule 912(5). (R 336.1912) 8. Approval of this permit does not exempt the permittee from complying with any future applicable requirements which may be promulgated under Part 55 of 1994 PA 451, as amended or the Federal Clean Air Act. 9. Approval of this permit does not obviate the necessity of obtaining such permits or approvals from other units of government as required by law. 10. Operation of this equipment may be subject to other requirements of Part 55 of 1994 PA 451, as amended and the rules promulgated thereunder.

Permit No. 78-15D Page 4 of 50 11. Except as provided in subrules (2) and (3) or unless the special conditions of the Permit to Install include an alternate opacity limit established pursuant to subrule (4) of R 336.1301, the permittee shall not cause or permit to be discharged into the outer air from a process or process equipment a visible emission of density greater than the most stringent of the following. The grading of visible emissions shall be determined in accordance with R 336.1303. (R 336.1301) a) A six-minute average of 20 percent opacity, except for one six-minute average per hour of not more than 27 percent opacity. b) A visible emission limit specified by an applicable federal new source performance standard. c) A visible emission limit specified as a condition of this Permit to Install. 12. Collected air contaminants shall be removed as necessary to maintain the equipment at the required operating efficiency. The collection and disposal of air contaminants shall be performed in a manner so as to minimize the introduction of contaminants to the outer air. Transport of collected air contaminants in Priority I and II areas requires the use of material handling methods specified in R 336.1370(2). (R 336.1370) 13. The Department may require the permittee to conduct acceptable performance tests, at the permittee s expense, in accordance with R 336.2001 and R 336.2003, under any of the conditions listed in R 336.2001. (R 336.2001)

Permit No. 78-15D Page 5 of 50 SPECIAL CONDITIONS EMISSION UNIT SUMMARY TABLE The descriptions provided below are for informational purposes and do not constitute enforceable conditions. Emission Unit ID Emission Unit Description (Process Equipment & Control Devices) Installation Date / Modification Date Flexible Group ID EU-Melt1 10.1 MMBtu/hr natural gas fired aluminum melting furnace No. 1 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Nitrogen gas is bubbled through the molten aluminum to remove impurities. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-Melt2 10.1 MMBtu/hr natural gas fired aluminum melting furnace No. 2 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Nitrogen gas is bubbled through the molten aluminum to remove impurities. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-Chip1 6.2 MMBtu/hr natural gas fired aluminum chip melting furnace No. 1 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Nitrogen gas is bubbled through the molten aluminum to remove impurities. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-Chip2 6.2 MMBtu/hr natural gas fired aluminum chip melting furnace No. 2 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Nitrogen gas is bubbled through the molten aluminum to remove impurities. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-Hold1 2.7 MMBtu/hr natural gas fired aluminum holding melting furnace No. 1 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-Hold2 2.7 MMBtu/hr natural gas fired aluminum holding melting furnace No. 2 with a retaining capacity of 13.2 tons. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z EU-LadleHood Fluxing and drossing station for the transfer ladles. A dry, solid fluxing agent is used for removing impurities in the molten aluminum. Nitrogen gas is bubbled through the molten aluminum to remove impurities. Ducted to a common lime injected baghouse. 2017 FG-Melting, FG-MACT6Z

Permit No. 78-15D Page 6 of 50 Emission Unit ID EU-ChipDryer EU-MoldPreHeat EU-MoldCoatFurn EU- MoldSonicClean EU-DieCasting EU-SandBlast EU-HeatTreat1 EU-HeatTreat2 Emission Unit Description (Process Equipment & Control Devices) Machining fluid removal system and thermal chip dryer. A spinner will use centrifugal force to mechanically remove excess emulsion fluid from the chips, followed by a thermal chip dryer for volatilizing remaining emulsion on the chips using natural gas combustion (6.0 MMBtu/hr) for heat. The air pollution control equipment will consist of a high efficiency cyclone for PM control, with a thermal oxidizer to control VOC. 1.86 MMBtu/hr natural gas combustion furnace for preheating the die casting molds. Furnace has 3 burners each rated at 180 kw. Exhaust gases are vented with EU- MoldCoatFurn. 1.24 MMBtu/hr two-chamber natural gas combustion furnace for drying the water-based mold coating. Furnace has 2 burners each rated at 180 kw. Furnace includes two rail car bays. Exhaust gases are vented with EU- MoldPreHeat. Mold sonic cleaner baths consisting of alkaline cleaner, rinse, followed by rust inhibitor used to clean the molds before casting. Vapors from the baths are vented externally out the wall. 28 low-pressure die casting machines used to form the shape of the aluminum wheels. There is no dedicated exhaust system for the die casting machines. Molten aluminum is transported to the electric holding furnaces of the die casting machines. A solid fluxing agent is used in the die casting machines holding furnaces for removing impurities in the molten aluminum prior to the aluminum being injected into the molds. A cooling tower is used to cool process water. Process water is used to cool the molds in the die casting machines. Sand blasting machine used to clean the molds following casting. The emissions from the sand blasting machine are controlled by a fabric filter. 10 MMBtu/hr natural gas combustion heat treatment Line 1, consisting of a solution furnace and aging furnace for enhancing metallurgical/mechanical properties. Waste heat from the solution furnace is directed into the aging furnace to promote energy efficiency and cost savings. From the solution furnace, the wheels are quenched in a water bath. After quenching, the wheels enter the aging furnace. 10 MMBtu/hr natural gas combustion heat treatment Line 2, consisting of a solution furnace and aging furnace for enhancing metallurgical/mechanical properties. Waste heat from the solution furnace is directed into the aging furnace to promote energy efficiency and cost savings. From the solution furnace, the wheels are quenched in a water bath. After quenching, the wheels enter the aging furnace. Installation Date / Modification Date Flexible Group ID 2017 2017 2017 2017 2017 2017 2016 FG-HeatTreat 2016 FG-HeatTreat

Permit No. 78-15D Page 7 of 50 Emission Unit ID EU-HeatTreat3 EU-Pretreatment EU-PretreatOven Emission Unit Description (Process Equipment & Control Devices) 10 MMBtu/hr natural gas combustion heat treatment Line 3, consisting of a solution furnace and aging furnace for enhancing metallurgical/mechanical properties. Waste heat from the solution furnace is directed into the aging furnace to promote energy efficiency and cost savings. From the solution furnace, the wheels are quenched in a water bath. After quenching, the wheels enter the aging furnace. Wheel surface preparation consisting of degreasing tanks (3), acidic, passivation and sealant tanks, which will be spray apply acidic or alkaline solutions to degrease (remove the machining fluid) and prepare the surface for proper coating adhesion to the aluminum. During various steps in the surface preparation process, water will be used to rinse off the alkaline and acidic solutions. 7.6 MMBtu/hr natural gas combustion oven for removing the surface moisture on the wheels the surfaces that have been treated. Installation Date / Modification Date Flexible Group ID 2016 FG-HeatTreat 7-30-2015 7-30-2015 EU-PaintShopBlr 11.2 MMBtu/hr natural gas combustion paint shop boiler 7-30-2015 EU-PrimePowder EU-PrimeOven EU-ClearPowder EU-ClearOven EU-LiquidCoat EU- BrushingBurr EU-Gen1 Primer powder coating booths No. 1 and 2. the powder coating operation uses a dry filtering system to capture and reuse excess powder (overspray). 3.5 MMBtu/hr natural gas combustion curing oven for curing primer powder coating. Clear powder coating booth No. 1. The powder coating operation uses a dry filtering system to capture and reuse excess powder (overspray). 3.5 MMBtu/hr natural gas combustion curing oven for curing clear powder coating. One base liquid coating booth and one clear liquid coating booth, each utilizing high volume low pressure (HVLP) or comparable applicators, associated flash off tunnels, and one 2.6 MMBtu/hr natural gas combustion curing oven. The VOC emissions from this line will be controlled by nonfugitive enclosure (NFE) and a recuperative thermal oxidizer (TO). The particulate emissions controlled by water spray. 12 brushing burr machines controlled by a common fabric filter. A diesel-fueled emergency engine with a model year of 2006 or later, and a displacement of less than 30 liters/cylinder, rated at 1MW (approximately 1,340 bhp). This emergency engine is subject to the New Source Performance Standards Stationary for Reciprocating Internal Combustion Engines (RICE), combustion ignition, emergency RICE less than 3000 HP. 7-30-2015 7-30-2015 7-30-2015 7-30-2015 FG- PowderCoating FG- PowderCoating FG- PowderCoating FG- PowderCoating 7-30-2015 7-30-2015 7-30-2015 Changes to the equipment described in this table are subject to the requirements of R 336.1201, except as allowed by R 336.1278 to R 336.1290.

Permit No. 78-15D Page 8 of 50 The following conditions apply to: EU-ChipDryer DESCRIPTION: Machining fluid removal system and thermal chip dryer. A spinner will use centrifugal force to mechanically remove excess emulsion fluid from the chips, followed by a thermal chip dryer for volatilizing remaining emulsion on the chips using natural gas combustion (6.0 MMBtu/hr) for heat. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: The air pollution control equipment will consist of a high efficiency cyclone for PM control, with a thermal oxidizer to control VOC. I. EMISSION LIMITS Pollutant Limit Time Period/ Operating Scenario Equipment Testing / Monitoring Method Underlying Applicable 1. PM 0.58 pph Test Protocol* EU-ChipDryer SC V.1. R 336.1331 2. PM10 0.51 pph Test Protocol* EU-ChipDryer SC V.1. R 336.1205, 40 CFR 52.21(c) & 3. PM2.5 0.26 pph Test Protocol* EU-ChipDryer SC V.1. 4. VOC 17.1 tpy 5. Dioxins and furans 3.5 x 10-5 gr D/F TEQ per ton of feed/charge *Test Protocol shall specify averaging time. 12-month rolling time period as determined at the end of each calendar month. (d) R 336.1205, 40 CFR 52.21(c) & (d) EU-ChipDryer SC VI.5 R 336.1702(a) Test Protocol* EU-ChipDryer SC V.2 40 CFR 63.1503, 40 CFR 63.1505(c)(2) II. MATERIAL LIMITS Material 1. Chip processing rate 2. Chip processing rate Time Period / Limit Operating Scenario 3.31 tons per hour Calendar Day Average 20,834 tons per year 12-month rolling time period as determined at the end of each calendar month. Equipment Testing / Monitoring Method Underlying Applicable EU-ChipDryer SC VI.6 R 336.1205, R 336.1225, R 336.1702 40 CFR 52.21(c) & (d) EU-ChipDryer SC VI.7 R 336.1205, R 336.1225, R 336.1702 40 CFR 52.21(c) & (d) 3. The feedstock charged to EU-ChipDryer shall be only unpainted/uncoated aluminum chips. (40 CFR 63.1506(f)(3))

Permit No. 78-15D Page 9 of 50 III. PROCESS/OPERATIOL RESTRICTIONS 1. The permittee shall not operate EU-ChipDryer unless a minimum temperature of 1292 F (700 C) and a minimum retention time of 0.5 seconds in the thermal oxidizer is maintained. (R 336.1205, R 336.1225, R 336.1702(a), R 336.1910) 2. The permittee shall maintain the thermal oxidizer for EU-ChipDryer per the following requirements: a) Maintain the 3-hour block average operating temperature of the afterburner at or above the average temperature established during the performance test. b) Operate the thermal oxidizer in accordance with the OM&M plan. (40 CFR 63.1506(f)) 3. The permittee shall maintain and operate EU-ChipDryer according to the procedures outlined in the preventative maintenance plan OM&M Plan required in Subpart RRR requirements. (40 CFR Part 63 Subpart RRR) IV. DESIGN/EQUIPMENT PARAMETERS 1. The permittee shall not operate EU-ChipDryer unless either a device that measures and records measure and record the total weight of feed/charge to or the aluminum production from, the affected source or emission unit over the same operating cycle or time period used in the performance test is installed, maintained, and operated in a satisfactory manner or an acceptable alternative procedure is implemented. As an alternative to a measurement device, the owner or operator may use a procedure acceptable to the AQD District Supervisor to determine the total weight of feed/charge or aluminum production to the affected source or emission unit. The device or procedure shall meet the following criteria: a) The accuracy of the weight measurement device or procedure shall be ±1 percent of the weight being measured. The owner or operator may apply to the permitting agency for approval to use a device of alternative accuracy if the required accuracy cannot be achieved as a result of equipment layout or charging practices. A device of alternative accuracy will not be approved unless the owner or operator provides assurance through data and information that the affected source will meet the relevant emission standard. b) The owner or operator shall verify the calibration of the weight measurement device in accordance with the schedule specified by the manufacturer, or if no calibration schedule is specified, at least once every 6 months. (R 336.1205, R 336.1224, R 336.1225, 40 CFR 63.1510(e)) 2. The permittee shall not operate EU-ChipDryer unless the capture and control equipment meets the following requirements: a) Design and install a system for the capture and collection of emissions to meet the engineering standards for minimum exhaust rates as published by the American Conference of Governmental Industrial Hygienists in chapters 3 and 5 of Industrial Ventilation: A Manual of Recommended Practice (incorporated by reference in 63.1502 of this subpart). b) Vent captured emissions through a closed system, except that dilution air may be added to emission streams for the purpose of controlling temperature at the inlet to a fabric filter. c) Operate each capture/collection system according to the procedures and requirements in the OM&M plan. (40 CFR 63.1506(c)) 3. The permittee shall not operate EU-ChipDryer unless the capture system and the cyclone and thermal oxidizers are installed, maintained, and operated in accordance with the manufacturer s recommendations. (R 336.1205(1)(a) & (3), R 336.1224, R 336.1225, R 336.1301, R 336.1331, R 336.1910)

Permit No. 78-15D Page 10 of 50 4. The permittee shall not operate EU-ChipDryer unless the thermal oxidizer is installed, maintained and operated in a satisfactory manner. Satisfactory operation of the thermal oxidizer includes a minimum VOC destruction efficiency of 95 percent (by weight), and maintaining a minimum temperature of 1292 F (700 C) and a minimum retention time of 0.5 seconds. (R 336.1205, R 336.1224, R 336.1225, R 336.1702, R 336.1910) 5. The permittee shall install, calibrate, maintain and operate in a satisfactory manner a temperature monitoring device in the combustion chamber of the thermal oxidizer to monitor and record the temperature on a continuous basis, during operation of EU-ChipDryer. (R 336.1205, R 336.1224, R 336.1225, R 336.1702, 40 CFR 63.1510(g)) V. TESTING/SAMPLING 1. Within 180 days after commencement of trial operation, the permittee shall verify the destruction efficiency of the thermal oxidizer, PM, PM10, and PM2.5 emission rates from EU-ChipDryer by testing at owner's expense, in accordance with Department requirements. No less than 60 prior to testing, the permittee shall submit a complete test plan to the AQD Technical Programs Unit and District Office. The AQD must approve the final plan prior to testing. Verification of emission rates includes the submittal of a complete report of the test results to the AQD Technical Programs Unit and District Office within 60 days following the last date of the test. (R 336.1205(1)(a) & (3), R 336.1225, R 336.2001, R 336.2003, R 336.2004, 40 CFR 52.21(c) & (d)) 2. Within 90 days after commencement of trial operation, the permittee shall verify dioxin/furan emission rates while processing unpainted aluminum chips from EU-ChipDryer by testing at owner's expense, in accordance with Department requirements. No less than 60 prior to testing, the permittee shall submit a complete test plan to the AQD Technical Programs Unit and District Office. The AQD must approve the final plan prior to testing. Verification of emission rates includes the submittal of a complete report of the test results to the AQD Technical Programs Unit and District Office within 60 days following the last date of the test. (R 336.1205(1)(a) & (3), R 336.1225, R 336.2001, R 336.2003, R 336.2004,, 40 CFR 63.1511) VI. MONITORING/RECORDKEEPING 1. The permittee shall complete all required calculations in a format acceptable to the AQD District Supervisor by the 30th day of the calendar month, for the previous calendar month, unless otherwise specified in any monitoring/recordkeeping special condition. (R 336.1205(1)(a) & (3), 40 CFR 52.21 (c) & (d)) 2. The monitoring system for the thermal oxidizer shall record the temperature in 15-minute block averages and determine and record the average temperature for each 3-hour block period. (40 CFR 63.1510(g)) 3. The permittee shall monitor and record, in a satisfactory manner, the weight of feed/charge to EU-ChipDryer for each operating cycle or time period used in the performance test required in SC V.2. (R 336.1205, R 336.1224, R 336.1225, R 336.1702, ) 4. The permittee shall monitor, in a satisfactory manner, the temperature in the thermal oxidizer on a continuous basis in a manner and with instrumentation acceptable to the Air Quality Division. (R 336.1205, R 336.1224, R 336.1225, R 336.1702) 5. The permittee shall keep, in a satisfactory manner, VOC emission calculations on a monthly and 12-month rolling time period basis for EU-ChipDryer. The permittee shall keep all records on file and make them available to the Department upon request. (R 336.1205, R 336.1224, R 336.1225, R 336.1702)

Permit No. 78-15D Page 11 of 50 6. The permittee shall keep on a daily basis, in a satisfactory manner, a log of the hourly average throughput rate and types of material charged in EU-ChipDryer. As an alternative to a measurement device, the owner or operator may use a procedure acceptable to the AQD District Supervisor to determine the total weight of feed/charge or aluminum production to the affected source or emission unit. The permittee shall keep all records on file for a period of at least five years and make them available to the Department upon request. (R 336.1205, R 336.1220, R 336.1225, R 336.1702, 40 CFR 63.1510(e)) 7. The permittee shall keep, in a satisfactory manner, monthly and 12-month rolling time period records of the total weight of charge materials in EU-ChipDryer. As an alternative to a measurement device, the owner or operator may use a procedure acceptable to the AQD District Supervisor to determine the total weight of feed/charge or aluminum production to the affected source or emission unit. The permittee shall keep all records on file at the facility and make them available to the Department upon request. (R 336.1205, R 336.1225, 40 CFR 63.1510(e)) VII. REPORTING 1. The permittee shall submit a certification of compliance with the applicable operational standard for charge materials in 40 CFR 63.1506(f)(3) for each 6-month reporting period. Each certification must contain the information in 40 CFR 63.1516(b)(2)(i). (40 CFR 63.1510(k)) VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) 1. SV-101CHPP 44.0 65.0 Underlying Applicable R 336.1225, IX. OTHER REQUIREMENTS 1. The permittee shall comply with the provisions of the National Emission Standards for Hazardous Air Pollutants, as specified in 40 CFR, Part 63, Subpart A and Subpart RRR, as they apply to EU-ChipDryer, upon startup. (40 CFR Part 63 Subparts A and RRR) Footnotes: 1 This condition is state only enforceable and was established pursuant to Rule 201(1)(b).

Permit No. 78-15D Page 12 of 50 The following conditions apply to: EU-MoldPreHeat DESCRIPTION: 1.86 MMBtu/hr natural gas combustion furnace for preheating the die casting molds. Furnace has 3 burners each rated at 180 kw. Exhaust gases are vented with EU-MoldCoatFurn. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS II. MATERIAL LIMITS 1. The permittee shall burn only pipeline quality natural gas in EU-MoldPreHeat. (R 336.1205(1)(a) & (3), R 336.1224, R 336.1225, R 336.1702(a), ) III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS 1. The maximum design heat input capacity for EU-MoldPreHeat shall not exceed 180 kilowatts per burner. (R 336.1205(1)(a) & (3), ) V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING VII. REPORTING

Permit No. 78-15D Page 13 of 50 VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) Underlying Applicable 1. SV-202MLD 16.0 32.8 R 336.1225, IX. OTHER REQUIREMENTS

Permit No. 78-15D Page 14 of 50 The following conditions apply to: EU-MoldCoatFurn DESCRIPTION: 1.24 MMBtu/hr two-chamber natural gas combustion furnace for drying the water-based mold coating. Furnace has 2 burners each rated at 180 kw. Furnace includes two rail car bays. Exhaust gases are vented with EU-MoldPreHeat. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS II. MATERIAL LIMITS 1. The permittee shall burn only pipeline quality natural gas in EU-MoldCoatFurn. (R 336.1205(1)(a) & (3), R 336.1224, R 336.1225, R 336.1702(a), ) III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS 1. The maximum design heat input capacity for EU-MoldCoatFurn shall not exceed180 kilowatts per burner. (R 336.1205(1)(a) & (3), ) V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING VII. REPORTING

Permit No. 78-15D Page 15 of 50 VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) Underlying Applicable 1. SV-202MLD 16.0 32.8 R 336.1225, IX. OTHER REQUIREMENTS

Permit No. 78-15D Page 16 of 50 The following conditions apply to: EU-MoldSonicClean DESCRIPTION: Mold sonic cleaner baths consisting of alkaline cleaner, rinse, followed by rust inhibitor used to clean the molds before casting. Vapors from the baths are vented externally out the wall. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS II. MATERIAL LIMITS III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING 1. The permittee shall maintain a current listing from the manufacturer of the chemical composition of each material, such as cleaners and rust inhibitors, used in EU-MoldSonicClean, including the weight percent of each component. The data may consist of Material Safety Data Sheets, manufacturer s formulation data, or both as deemed acceptable by the AQD District Supervisor. The permittee shall keep all records on file and make them available to the Department upon request. 1 (R 336.1224, R 336.1225) VII. REPORTING VIII. STACK/VENT RESTRICTIONS IX. OTHER REQUIREMENTS Footnotes: 1 This condition is state only enforceable and was established pursuant to Rule 201(1)(b).

Permit No. 78-15D Page 17 of 50 The following conditions apply to: EU-DieCasting DESCRIPTION: 28 low-pressure die casting machines used to form the shape of the aluminum wheels. There is no dedicated exhaust system for the die casting machines. Molten aluminum is transported to the electric holding furnaces of the die casting machines. A solid fluxing agent is used in the die casting machines holding furnaces for removing impurities in the molten aluminum prior to the aluminum being injected into the molds. A cooling tower is used to cool process water. Process water is used to cool the molds in the die casting machines Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS Pollutant Limit Time Period / Operating Scenario Equipment 1. PM 0.005% Drift Loss Test Protocol* EU-DieCasting cooling tower *Test protocol shall specify averaging time. Testing / Monitoring Method Underlying Applicable GC 13 R 336.1301, R 336.1331 II. MATERIAL LIMITS Material 1. Mold Release Usage Time Period / Limit Operating Scenario 11 tpy 12-month rolling time period basis as determined at the end of each Equipment Testing / Monitoring Method Underlying Applicable EU-DieCasting SC VI.4 R 336.1225, 40 CFR 52.21(c) & (d) calendar month 2. Flux Usage 80 lb/8-hours Daily average EU-DieCasting SC VI.3 R 336.1225, 40 CFR 52.21(c) & (d) 3. Flux Usage 92,594 lb/yr 12-month rolling time period basis as determined at the end of each calendar month EU-DieCasting SC VI.4 R 336.1225, 40 CFR 52.21(c) & (d) III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS

Permit No. 78-15D Page 18 of 50 V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING 1. The permittee shall complete all required calculations in a format acceptable to the AQD District Supervisor by the 30 th day of the calendar month, for the previous calendar month, unless otherwise specified in any monitoring/recordkeeping special condition. (R 336.1205(1)(a) & (3), 40 CFR 52.21 (c) & (d)) 2. The permittee shall keep, in a satisfactory manner, monthly records of the HCl emission rate on a monthly and 12-month rolling time period basis for EU-DieCasting. The permittee shall keep all records on file at the facility and make them available to the Department upon request. 1 (R 336.1225) 3. The permittee shall monitor and record, in a satisfactory manner, the weight and description of the flux added to EU-DieCasting on a daily basis. The permittee shall keep all records on file at the facility and make them available to the Department upon request. (R 336.1224, R 336.1225, R 336.1301, R 336.1331) 4. The permittee shall monitor and record, in a satisfactory manner, the mold release and flux usage rate for EU-DieCasting on a monthly and 12-month rolling time period basis. The permittee shall keep all records on file and make them available to the Department upon request. (R 336.1225, R 336.1702(a), 40 CFR 52.21 (c) & (d)) VII. REPORTING VIII. STACK/VENT RESTRICTIONS IX. OTHER REQUIREMENTS Footnotes: 1 This condition is state only enforceable and was established pursuant to Rule 201(1)(b).

Permit No. 78-15D Page 19 of 50 The following conditions apply to: EU-SandBlast DESCRIPTION: Sand Blasting Machine used to clean the molds following casting. The emissions from the sand blasting machine are controlled by a fabric filter. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: Fabric Filter I. EMISSION LIMITS Pollutant Limit Time Period / Operating Scenario Equipment Testing / Monitoring Method Underlying Applicable Test Protocol* EU-SandBlast GC 13 R 336.1331 1. PM 0.007 grains per dscf gas a a Calculated on a dry gas basis * Test protocol shall specify averaging time II. MATERIAL LIMITS III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS 1. The permittee shall not operate EU-SandBlast unless the fabric filter is installed, maintained, and operated in a satisfactory manner. (R 336.1205, R 336.1224, R 336.1225, R 336.1331, R 336.1910, 40 CFR 52.21(c) & (d)) 2. The permittee shall install, calibrate, maintain and operate in a satisfactory manner a device to monitor and record the pressure drop across the fabric filter for EU-SandBlast. (R 336.1205, R 336.1224, R 336.1225, R 336.1301, R 336.1331, R 336.1910, 40 CFR 52.21) V. TESTING/SAMPLING

Permit No. 78-15D Page 20 of 50 VI. MONITORING/RECORDKEEPING 1. The permittee shall complete all required calculations in a format acceptable to the AQD District Supervisor and make them available by the 30 th day of the calendar month, for the previous calendar month, unless otherwise specified in any monitoring/recordkeeping special condition. (R 336.1205, R 336.1224, R 336.1225, R 336.1702) 2. The permittee shall monitor and record the pressure drop across the fabric filter for EU-SandBlast on a once daily basis during operation. (R 336.1205, R 336.1224, R 336.1225, R 336.1301, R 336.1331, R 336.1602, R 336.1702, R 336.1910, 40 CFR 52.21) VII. REPORTING VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) Underlying Applicable 1. SV-201SAND 12.2 14.7 R 336.1225, IX. OTHER REQUIREMENTS

Permit No. 78-15D Page 21 of 50 The following conditions apply to: EU-Pretreatment DESCRIPTION: Wheel surface preparation consisting of degreasing tanks (3), acidic, passivation and sealant tanks, which will be spray apply acidic or alkaline solutions to degrease (remove the machining fluid) and prepare the surface for proper coating adhesion to the aluminum. During various steps in the surface preparation process, water will be used to rinse off the alkaline and acidic solutions. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS II. MATERIAL LIMITS III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING 1. The permittee shall complete all required calculations in a format acceptable to the AQD District Supervisor by the 30 th day of the calendar month, for the previous calendar month, unless otherwise specified in any monitoring/recordkeeping special condition. (R 336.1205(3), R 336.1225, R 336.1702(a)) 2. The permittee shall keep, in a satisfactory manner, monthly and 12-month rolling time period records of the amounts of acid and degreasing solvent added each month and 12-month rolling time period. The permittee shall keep all records on file and make them available to the Department upon request. (R 336.1205(3), R 336.1225, R 336.1702(a))

Permit No. 78-15D Page 22 of 50 VII. REPORTING VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) Underlying Applicable 1. SV-502PT 20.9 1 52.5 1 R 336.1225 2. SV-503PT 25.6 1 52.5 1 R 336.1225 IX. OTHER REQUIREMENTS Footnotes: 1 This condition is state only enforceable and was established pursuant to Rule 201(1)(b).

Permit No. 78-15D Page 23 of 50 The following conditions apply to: EU-PretreatOven DESCRIPTION: 7.6 MMBtu/hr Natural Gas Combustion Oven for removing the surface moisture on the wheels the surfaces that have been treated. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS Pollutant Limit Time Period / Operating Scenario Equipment Testing / Monitoring Method 1. NOx 75 ppmv @ 3% Oxygen (O2) Test Protocol* EU-PretreatOven SC VI.1, GC 13 *Test Protocol shall specify averaging time. Underlying Applicable R 336.1205 II. MATERIAL LIMITS 1. The permittee shall burn only pipeline quality natural gas in EU-PretreatOven. (R 336.1205(1)(a) & (3), R 336.1224, R 336.1225, R 336.1702(a), ) III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS 1. The maximum design heat input capacity for EU-PretreatOven shall not exceed 7.6 MMBtu per hour on a fuel heat input basis. (R 336.1205(1)(a) & (3), ) V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING 1. The permittee shall keep records of the NOx emission rate guaranteed by the manufacturer of EU-PretreatOven. (R 336.1205, ) VII. REPORTING

Permit No. 78-15D Page 24 of 50 VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) 1. SV-504DOHT 15.7 52.5 2. SV-505DOHT 15.7 52.5 Underlying Applicable R 336.1225, R 336.1225, IX. OTHER REQUIREMENTS

Permit No. 78-15D Page 25 of 50 The following conditions apply to: EU-PaintShopBlr DESCRIPTION: 11.2 MMBtu/hr Natural gas Combustion Paint Shop Boiler Flexible Group ID: POLLUTION CONTROL EQUIPMENT: I. EMISSION LIMITS Pollutant Limit Time Period / Operating Scenario Equipment Testing / Monitoring Method Underlying Applicable 1. NOx 75 ppmv @ 3% O2 Test Protocol* EU-PaintShopBlr SC VI.1, GC 13 R 336.1205 *Test Protocol shall specify averaging time. II. MATERIAL LIMITS 1. The permittee shall burn only pipeline quality natural gas in EU-PaintShopBlr. (R 336.1205(1)(a), R 336.1224, R 336.1225, R 336.1702(a),, 40 CFR 60 Subpart Dc) III. PROCESS/OPERATIOL RESTRICTIONS IV. DESIGN/EQUIPMENT PARAMETERS 1. The maximum design heat input capacity for EU-PaintShopBlr shall not exceed 11.2 MMBtu per hour on a fuel heat input basis. (R 336.1205(1)(a),, 40 CFR Part 60 Subpart Dc) V. TESTING/SAMPLING VI. MONITORING/RECORDKEEPING 1. The permittee shall keep records of the NOx emission rate guaranteed by the manufacturer of EU-PaintShopBlr. (R 336.1205, ) 2. The permittee shall monitor, in a satisfactory manner, the natural gas usage rate for EU-PaintShopBlr each calendar month. The permittee shall keep the records on file at the facility and make them available to the Department upon request. (R 336.1205,, 40 CFR 60.48c(g)) 3. The permittee shall monitor emissions, operating information, and keep records for EU-PaintShopBlr in accordance with the federal Standards of Performance for New Stationary Sources as specified in 40 CFR Part 60 Subparts A and Dc. The permittee shall make all records available to the Department upon request. (40 CFR Part 60 Subparts A and Dc)

Permit No. 78-15D Page 26 of 50 VII. REPORTING 1. The permittee shall submit notification of the date of construction and actual startup of EU-PaintShopBlr in accordance with NSPS 40 CFR 60.7. This notification shall include: a) The design heat input capacity of the affected facility and identification of fuels to be combusted in the affected facility. b) If applicable, a copy of any federally enforceable requirement that limits the annual capacity factor for any fuel or mixture of fuels under 40 CFR 60.42c, or 40 CFR 60.43c. c) The annual capacity factor at which the owner or operator anticipates operating the affected facility based on all fuels fired and based on each individual fuel fired. d) Notification if an emerging technology will be used for controlling SO 2 emissions. The Administrator will examine the description of the control device and will determine whether the technology qualifies as an emerging technology. In making this determination, the Administrator may require the owner or operator of the affected facility to submit additional information concerning the control device. The affected facility is subject to the provisions of 40 CFR 60.42c(a) or (b)(1), unless and until this determination is made by the Administrator. (40 CFR 60.7, 40 CFR 60.48c) VIII. STACK/VENT RESTRICTIONS The exhaust gases from the stacks listed in the table below shall be discharged unobstructed vertically upwards to the ambient air unless otherwise noted: Stack & Vent ID Maximum Exhaust Diameter/Dimensions (inches) Minimum Height Above Ground (feet) Underlying Applicable 1. SV-532BLR 26 59.1 R 336.1225, IX. OTHER REQUIREMENTS 1. The permittee shall provide written notification of construction and operation to comply with the federal Standards of Performance for New Stationary Sources, 40 CFR 60.7. The permittee shall submit this notification to the AQD District Supervisor within the time frames specified in 40 CFR 60.7. (40 CFR 60.7) 2. The permittee shall comply with the provisions of the federal Standards of Performance for New Stationary Sources as specified in 40 CFR Part 60 Subpart A and Subpart Dc, as they apply to EU-PaintShopBlr. (40 CFR Part 60 Subparts A & Dc)

Permit No. 78-15D Page 27 of 50 The following conditions apply to: EU-LiquidCoat DESCRIPTION: One Base liquid coating booth and one Clear liquid coating booth, each utilizing high volume low pressure (HVLP) or comparable applicators, associated flash off tunnels, and one 2.6 MMBtu/hr Natural Gas Combustion Curing Oven. The VOC emissions from this line will be controlled by Non-Fugitive Enclosure (NFE) and a recuperative thermal oxidizer (TO). The particulate emissions controlled by water spray. Flexible Group ID: POLLUTION CONTROL EQUIPMENT: Thermal Oxidizer I. EMISSION LIMITS Pollutant Limit 1. VOCs 17.5 tpy 2. Heavy aromatic solvent naphtha (CAS No. 64742-94-5) 3. Mixed Xylenes (CAS No. 1330-20-7) 4. Butyl carbitol (CAS No. 112-34-5) 5. Formaldehyde (CAS No. 50-00-0) 6. Naphthalene (CAS No. 91-20-3) Time Period / Operating Scenario 12-month rolling time period as determined at the end of each calendar month Equipment EU-LiquidCoat Testing / Monitoring Method SC VI.3 Underlying Applicable R 336.1205, R 336.1702(a) 105.50 lb/day 1 Calendar day EU-LiquidCoat SC VI.4 R 336.1225 150.66 lb/day 1 Calendar day EU-LiquidCoat SC VI.4 R 336.1225 30.14 lb/day 1 Calendar day EU-LiquidCoat SC VI.4 R 336.1225 12-month rolling time 0.83 tpy 1 period as determined at the end of each calendar month 12-month rolling time 0.18 tpy 1 period as determined at the end of each calendar month EU-LiquidCoat SC VI.4 R 336.1225 EU-LiquidCoat SC VI.4 R 336.1225 II. MATERIAL LIMITS III. PROCESS/OPERATIOL RESTRICTIONS 1. The permittee shall capture all waste materials and shall store them in closed containers. The permittee shall dispose of all waste materials in an acceptable manner in compliance with all applicable state rules and federal regulations. (R 336.1702(a)) 2. The permittee shall dispose of spent filters in a manner which minimizes the introduction of air contaminants to the outer air. (R 336.1370) 3. The permittee shall handle all VOC and HAP containing materials, including coatings, reducers, solvents and thinners, in a manner to minimize the generation of fugitive emissions. The permittee shall keep containers covered at all times except when operator access is necessary. (R 336.1205(3), R 336.1225, R 336.1702(a))

Permit No. 78-15D Page 28 of 50 4. The permittee shall not operate the thermal oxidizer (TO) for EU-LiquidCoat unless an updated malfunction abatement plan (MAP) as described in Rule 911(2), has been submitted within 90 days of permit issuances, and is implemented and maintained. The MAP shall, at a minimum, specify the following: a) A complete preventative maintenance program including identification of the supervisory personnel responsible for overseeing the inspection, maintenance, and repair of air-cleaning devices, a description of the items or conditions that shall be inspected, the frequency of the inspections or repairs, and an identification of the major replacement parts that shall be maintained in inventory for quick replacement. b) An identification of the sources and air cleaning operating variables that shall be monitored to detect a malfunction or failure, the normal operating range of these variables, and a description of the method of monitoring or surveillance procedures. c) A description of the corrective procedures or operational changes that shall be taken in the event of a malfunction or failure to achieve compliance with the applicable emission limits. d) A description of the procedures to capture, handle, and dispose of all materials to minimize the generation of fugitive emissions per SC III.1 and III.2. If at any time the MAP fails to address or inadequately addresses an event that meets the characteristics of a malfunction, the permittee shall amend the MAP within 45 days after such an event occurs. The permittee shall also amend the MAP within 45 days, if new equipment is installed or upon request from the District Supervisor. The permittee shall submit the MAP and any amendments to the MAP to the AQD District Supervisor for review and approval. If the AQD does not notify the permittee within 90 days of submittal, the MAP or amended MAP shall be considered approved. Until an amended plan is approved, the permittee shall implement corrective procedures or operational changes to achieve compliance with all applicable emission limits. (R 336.1205, R 336.1225, R 336.1702(a), R 336.1910, R 336.1911) IV. DESIGN/EQUIPMENT PARAMETERS 1. The permittee shall not operate EU-LiquidCoat unless all respective exhaust filters are installed and operating in a satisfactory manner. (R 336.1301, R 336.1910) 2. The permittee shall equip and maintain EU-LiquidCoat with HVLP or comparable technology with equivalent transfer efficiency. For HVLP applicators, the permittee shall keep test caps available for pressure testing. (R 336.1702(a)) 3. The permittee shall not operate EU-LiquidCoat unless the thermal oxidizer is installed, maintained and operated in a satisfactory manner. Satisfactory operation of the thermal oxidizer includes a minimum VOC destruction efficiency of 95 percent (by weight) and maintaining a minimum temperature of 1292 F (700 C) and a minimum retention time of 0.5 seconds. (R 336.1205, R 336.1225, R 336.1702, R 336.1910) 4. The permittee shall install, calibrate, maintain and operate in a satisfactory manner a temperature monitoring device in the combustion chamber of the thermal oxidizer to monitor and record the temperature on a continuous basis, during operation of EU-LiquidCoat. (R 336.1205, R 336.1224, R 336.1225, R 336.1702) 5. The permittee shall not operate any portion of EU-LiquidCoat unless the non-fugitive enclosure is installed, maintained and operated in a satisfactory manner. Satisfactory operation requires that the non-fugitive enclosure and oven are operating at a pressure lower than all adjacent areas, so that air flows into the nonfugitive enclosure through all natural draft openings (NDOs). NDO is defined as any opening that is not connected to a duct in which a fan or blower is installed. The cooling chamber following the oven may be operated at positive pressure. (R 336.1225, R 336.1702, R 336.1910)