Gas Trade Unit 22: Venting Systems

TSSA G2 Certification - Practice Questions & Chapter Reviews

📋 Certification Level: TSSA G2 (Gas Technician 2 - Intermediate)

⚠️ Prerequisites: G3 Certification + 2 Years (4,000 hours) Experience

Master Gas Trade Unit 22 with free CSA B149.1-25 compliant practice questions for the TSSA G2 certification exam. This unit covers venting systems, vent sizing, Category I appliances, and combustion air requirements - heavily tested on the G2 exam.

📖 What This Unit Covers

Gas Trade Unit 22 focuses on venting and combustion air systems:

Chapter 1: Venting Systems - Vent types and materials
Chapter 2: Vent Installation and Assembly - Assembly and installation procedures
Chapter 3: Vent Design and Installation Requirements for Category I Appliances - Design requirements
Chapter 4: Size Venting Systems for Category I Appliances - Vent sizing calculations
Chapter 5: Vent Inspection - Inspection procedures and deficiencies
Chapter 6: Air Requirements - Combustion and ventilation air requirements

🎯 TSSA G2 Exam Relevance

CSA Code Reference: CSA B149.1-25 Section 7 (Venting and Combustion Air)

Exam Coverage: Venting systems topics appear in approximately 22-28% of G2 exam questions (heavily tested).

💡 Study Tips for Unit 22

Master vent sizing calculations using CSA tables
Understand Category I, II, III, IV appliance venting differences
Learn vent material requirements and connector sizing
Study combustion air calculation methods
Review common vent deficiencies and inspection techniques

Unit 22 - Venting Systems

Gas Trade Training - Chapter Questions

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⚠️ Educational Resource Disclaimer: This practice test is an independent educational resource designed to help students prepare for the TSSA G2 certification exam. These materials are based on CSA B149.1-25 requirements but are not official TSSA materials. G2 certification requires G3 prerequisite plus 2 years (4,000 hours) documented experience. Always refer to the official CSA B149.1-25 code and current TSSA guidelines for authoritative information. LARK Labs is not affiliated with TSSA or CSA Group.

}, { question: "What is an induced draft?", options: [ "Draft produces by mechanical device downstream from the combustion zone.", "Draft produces by mechanical device upstream from the combustion zone.", "Draft produces by the upward movement of hot gases, creating a negative pressure.", "A condition in which a draft is forced downward and can cause flue gas spillage." ], correct: 0 }, { question: "What is a down draft?", options: [ "Draft produces by mechanical device downstream from the combustion zone.", "Draft produces by mechanical device upstream from the combustion zone.", "Draft produces by the upward movement of hot gases, creating a negative pressure.", "A condition in which a draft is forced downward and can cause flue gas spillage." ], correct: 3 }, { question: "What is a natural draft?", options: [ "Draft produces by mechanical device downstream from the combustion zone.", "Draft produces by mechanical device upstream from the combustion zone.", "Draft produce by the upward movement of hot gases creating a negative pressure.", "A condition in which a draft is forced downward and can cause flue gas spillage." ], correct: 2 }, { question: "Select the simplified imperial formula used to calculate theoretical draft.", options: [ "D = BTUH/(ΔT×1.08)", "D = 7.6 (Ts-Ta)/(Ts×Ta) H", "D = 3450 (Ts-Ta)/(Ts×Ta) H", "D = BTUH/(ΔT×500)" ], correct: 1 }, { question: "What combination will give the greatest draft?", options: [ "Lowest stack temperature, highest outdoor air temperature and shortest vent.", "Highest stack temperature, lowest outdoor air temperature and highest vent.", "Highest stack temperature, highest outdoor air temperature and highest vent.", "Lowest stack temperature, lowest outdoor air temperature and lowest vent." ], correct: 1 }, { question: "The average stack temperature is the average between the temperature at the flue collar and the temperature at the vent termination.", options: [ "True", "False" ], correct: 0 }, { question: "To extract heat from flue gases, what would be installed?", options: [ "A condenser", "A heat reclaimer", "A heat exchanger", "Heat recovery unit" ], correct: 1 }, { question: "Each vent system has a maximum capacity related to flow and a minimum capacity related to temperature.", options: [ "True", "False" ], correct: 0 }, { question: "There is no limit to the benefits gained by increasing the vent height.", options: [ "True", "False" ], correct: 1 } ] }, chapter2: { title: "Chapter 2: Vent Installation and Assembly", questions: [ { question: "Which vent type is capable of withstanding the highest flue gas temperature?", options: [ "Type A vent", "Type B vent", "Type C vent", "Type L vent" ], correct: 0 }, { question: "What is the maximum input of an appliance being vented through an exhaust canopy?", options: [ "12 kW", "40 kW", "120 kW", "400 kW" ], correct: 2 }, { question: "How are the joints on a C-vent secured?", options: [ "Gear clamps", "Three screws", "Locking bands", "Solvent cement" ], correct: 1 }, { question: "How are the joints on a BH Class II, A and B temperature rated, vents secured?", options: [ "Gear clamps", "Three screws", "Locking bands", "Solvent cement" ], correct: 3 }, { question: "How are the joints on a BH Class II, C temperature rated, vents secured?", options: [ "Gear clamps", "Three screws", "Locking bands", "Solvent cement" ], correct: 2 }, { question: "How are the joints on a BH Class II, D temperature rated, vents secured?", options: [ "Gear clamps", "Three screws", "Locking bands", "Solvent cement" ], correct: 0 }, { question: "What type of vent is used with a recessed wall furnace?", options: [ "Type B vent", "Type L vent", "Type BH vent", "Type BW vent" ], correct: 3 }, { question: "What is the maximum vent gas temperature for Type L vents?", options: [ "90°C (195°F)", "110°C (230°F)", "243°C (470°F)", "288°C (550°F)" ], correct: 3 }, { question: "What is the maximum vent gas temperature for Type BH Class IIB vents?", options: [ "90°C (195°F)", "110°C (230°F)", "243°C (470°F)", "288°C (550°F)" ], correct: 0 }, { question: "What is the maximum vent gas temperature for Type B vents?", options: [ "90°C (195°F)", "110°C (230°F)", "243°C (470°F)", "288°C (550°F)" ], correct: 2 }, { question: "What is the maximum vent gas temperature for Type BH Class IIC vents?", options: [ "90°C (195°F)", "110°C (230°F)", "243°C (470°F)", "288°C (550°F)" ], correct: 1 }, { question: "What type of BH vent is CPVC?", options: [ "Class I", "Class II A", "Class II B", "Class II C" ], correct: 2 }, { question: "What type of BH vent is Polypropylene?", options: [ "Class I", "Class II A", "Class II B", "Class II C" ], correct: 3 }, { question: "What type of BH vent is PVC?", options: [ "Class I", "Class II A", "Class II B", "Class II C" ], correct: 1 }, { question: "Except for a BH vent, what is the minimum height a vent must terminate above a flat roof?", options: [ "450 mm", "600 mm", "900 mm", "1500 mm" ], correct: 1 }, { question: "What is the minimum height a chimney must terminate above a flat roof?", options: [ "450 mm", "600 mm", "900 mm", "1500 mm" ], correct: 2 }, { question: "For a positive pressure BH vent, what is the minimum termination height above a flat roof?", options: [ "450 mm", "600 mm", "900 mm", "1500 mm" ], correct: 0 }, { question: "What is the minimum horizontal clearance from an obstruction to a vent termination without increasing the height?", options: [ "2 ft. (0.6 m)", "4 ft. (1.22 m)", "8 ft. (2.44 m)", "10 ft. (3.66 m)" ], correct: 3 }, { question: "As per Table 8.6 what is the minimum Type C vent connector clearance for a boiler?", options: [ "25 mm", "75 mm", "150 mm", "225 mm" ], correct: 2 } ] }, chapter3: { title: "Chapter 3: Vent Design and Installation Requirements for Category I Appliances", questions: [ { question: "Which category of appliance can be vented using the Annex C Code tables?", options: [ "Category I", "Category II", "Category III", "Category IV" ], correct: 0 }, { question: "A Type B vent passing through an unused masonry chimney flue shall be considered an exterior chimney.", options: [ "True", "False" ], correct: 1 }, { question: "When reducing the size of a vent connector from that of the draft-hood, what is the minimum total vent height required?", options: [ "5 ft", "10 ft", "15 ft", "20 ft" ], correct: 1 }, { question: "When sizing the vent for a high altitude installation, which rating is used when determining maximum capacity?", options: [ "Sea level rating", "High altitude rating", "Sea level rating plus 4%", "High altitude rating plus 4%" ], correct: 0 }, { question: "A single fan-assisted furnace may be vented into a tile lined masonry chimney.", options: [ "True", "False" ], correct: 1 }, { question: "A fan-assisted furnace may be vented into a masonry chimney that is serving a draft-hood-equipped appliance.", options: [ "True", "False" ], correct: 1 }, { question: "The vent for a fan assisted appliance with a 4\" flue collar may be reduced to 3\" if determined by the tables.", options: [ "True", "False" ], correct: 0 }, { question: "A single vented fan-assisted appliance requires 3 elbows for the vent connector. How will the table capacity need to be adjusted?", options: [ "Reduced by 5%", "Reduced by 10%", "Reduced by 15%", "Reduced by 25%" ], correct: 2 }, { question: "When the vent table permits more than one diameter of pipe that can be used for a connector or the vent, which is preferred: the larger or the smaller?", options: [ "Larger connector or vent", "Smaller connector or vent", "Smaller connector and larger vent", "Larger connector and smaller vent" ], correct: 1 }, { question: "If the vent connectors are connected to a horizontal common vent connector manifold, how must the common vent capacity table be adjusted?", options: [ "Increase 10%", "Reduced by 10%", "Increase by 11%", "Reduced by 11%" ], correct: 1 }, { question: "If the common vent is offset, how must the common vent capacity table be adjusted?", options: [ "Increase 20%", "Reduced by 20%", "Increase by 25%", "Reduced by 25%" ], correct: 1 }, { question: "Of the three configurations shown, which is the least effective in minimizing spillage?", options: [ "Configuration (a)", "Configuration (b)", "Configuration (c)", "Configuration (b &c)" ], correct: 0 } ] }, chapter4: { title: "Chapter 4: Size Venting Systems for Category I Appliances", questions: [ { question: "Size the individual vent for the following system specifications: Height: 35 ft., Lateral: 10 ft., Vent connector: Single wall, Appliance: NAT, Input: 265 Mbtu/h, Structure: Tight", options: [ "4\"", "5\"", "6\"", "7\"" ], correct: 3 }, { question: "Size the individual vent size for the following system specifications: Height: 20 ft., Lateral: 5 ft., Vent connector: Single wall, Appliance: FAN, Input: 160 Mbtu/h, Structure: Tight", options: [ "4\"", "5\"", "6\"", "7\"" ], correct: 1 }, { question: "Size the vent connector of appliance #1 for the following system specifications: Height: 32 ft., Rise #1: 3 ft., Rise #2: 3 ft., Vent connectors: Single wall, Appliances: FAN/NAT, Input Appliance #1: 40 Mbtu/h (NAT), Input Appliance #2: 165 Mbtu/h (FAN), Structure: Tight", options: [ "4\"", "5\"", "6\"", "7\"" ], correct: 0 }, { question: "Size the vent connector of appliance #2 for the following system specifications: Height: 32 ft., Rise #1: 3 ft., Rise #2: 3 ft., Vent connectors: Single wall, Appliances: FAN/NAT, Input Appliance #1: 40 Mbtu/h (NAT), Input Appliance #2: 165 Mbtu/h (FAN), Structure: Tight", options: [ "4\"", "5\"", "6\"", "7\"" ], correct: 1 }, { question: "Size the common vent for the following system specifications: Common vent has an offset using two 90° elbows, Height: 15 ft., Rise #1: 1 ft., Rise #2: 3 ft., Vent connectors: B vent, Appliances: FAN/NAT, Input Appliance #1: 75 Mbtu/h (NAT), Input Appliance #2: 250 Mbtu/h (FAN), Structure: Tight", options: [ "6\"", "7\"", "8\"", "9\"" ], correct: 3 }, { question: "Size the vent connector for the following system specifications: Individual appliance connected to a masonry chimney, Height: 10 ft., Lateral: 5 ft., Vent connectors: B vent, Appliances: NAT, Input: 200 Mbtu/h, Structure: Loose", options: [ "5\"", "6\"", "7\"", "8\"" ], correct: 2 }, { question: "What is the minimum internal area of a masonry chimney serving an individual appliance with the following system specifications: Individual appliance connected to a masonry chimney, Height: 10 ft., Lateral: 5 ft., Vent connectors: B vent, Appliances: NAT, Input: 200 Mbtu/h, Structure: Loose", options: [ "38 in²", "50 in²", "198 in²", "269 in²" ], correct: 1 }, { question: "What is the maximum internal area of a masonry chimney serving an individual appliance with the following system specifications: Individual appliance connected to a masonry chimney, Height: 10 ft., Lateral: 5 ft., Vent connectors: B vent, Appliances: NAT, Input: 200 Mbtu/h, Structure: Loose", options: [ "38 in²", "50 in²", "198 in²", "269 in²" ], correct: 3 }, { question: "What is the maximum length of an offset on a 6\" common vent", options: [ "4 ft.", "7.5 ft.", "9 ft.", "12 ft." ], correct: 2 }, { question: "As per Clause 8.12.8, what is the maximum listed table capacity of a chimney serving an appliance with an input of 120 Mbtu/h?", options: [ "113 Mbtu/h", "150 Mbtu/h", "187 Mbtu/h", "200 Mbtu/h" ], correct: 1 } ] }, chapter5: { title: "Chapter 5: Vent Inspection", questions: [ { question: "What is the most serious and hazardous venting problem?", options: [ "Corrosion", "Condensation", "Flue gas spillage", "Insufficient support" ], correct: 2 }, { question: "What is the most common cause of flue gas spillage on Category I appliances?", options: [ "Building depressurization", "Improper vent configuration", "Incorrectly sized venting system", "Blocked or restricted venting system" ], correct: 0 }, { question: "Category I fan-assisted appliances are more prone to suffer condensation problems from oversized venting systems?", options: [ "True", "False" ], correct: 0 }, { question: "What is the purpose of a spill switch?", options: [ "Sense a gas leak", "Sense a blocked vent", "Sense a water supply leak", "Signal water pressure relief valve activation" ], correct: 1 }, { question: "How can you remedy joint leakage problems with a Type B vent system installed on a Category IV appliance?", options: [ "Increase the vent size", "Increase the vent height", "Tape the joints externally", "Replace system with a proper Type BH vent" ], correct: 3 } ] }, chapter6: { title: "Chapter 6: Air Requirements", questions: [ { question: "How are air supply requirements for a direct vent appliance determined?", options: [ "Table 8.1", "Table 8.2", "Code clause 8.2.6", "Manufacturer's literature" ], correct: 3 }, { question: "What is the minimum required free area of a square combustion air opening?", options: [ "3 in²", "6 in²", "9 in²", "10 in²" ], correct: 2 }, { question: "The combustion air supply for a less than 400 MBtu/h installation must terminate within __________ above, and within ____________ horizontally from the burner level of the appliance having the largest input.", options: [ "1' , 2'", "2' , 3'", "3' , 4'", "4' , 5'" ], correct: 0 }, { question: "What is the smallest opening dimension in a fixed louvre, grille, or screen?", options: [ "1/8\"", "1/4\"", "1/2\"", "1\"" ], correct: 1 }, { question: "Under what conditions can a gas-fired appliance be installed in a building and not have a separate combustion air supply?", options: [ "Tight building of sufficient volume", "Loose building of less than 1000 ft²", "Loose building of sufficient volume", "Tight building appliance in an enclosure" ], correct: 2 }, { question: "When compared to the air supply opening, what is the minimum cross-sectional area of the ventilation air opening for an appliance over 400 MBtu/h?", options: [ "5% or 5 in²", "10% or 10 in²", "20% or 20in²", "50% or 50 in²" ], correct: 1 }, { question: "A single family dwelling complies with Clause 8.2.1(a) or (b). It has a boiler rated at 200 MBtu/h and a hot water storage tank rated at 110 MBtu/h. Both appliances are equipped with draft control devices. The air supply is brought from outdoors through a duct. Determine the area of air supply duct.", options: [ "22 in²", "25 in²", "40 in²", "47 in²" ], correct: 3 }, { question: "A structure conforms to Clause 8.2.1(a) or (b). It contains a boiler rated at 65 MBtu/h and a domestic hot water tank rated at 40 MBtu/h. Both appliances are designed for use with no draft control devices and the air supply is brought from outdoors through a duct. Determine the area of air supply duct.", options: [ "7 in²", "9 in²", "14 in²", "18 in²" ], correct: 1 }, { question: "A single family dwelling conforms to Clause 8.2.1(a) or (b). It has a furnace rated at 80 kW and a hot water tank rated at 30 kW. The furnace is equipped with a barometric draft control and the hot water tank has a draft-hood. The air supply is from outdoors. Determine the area of air supply duct.", options: [ "12,000 mm²", "14,000 mm²", "30,000 mm²", "35,000 mm²" ], correct: 3 }, { question: "A structure conforms to Clause 8.2.1(a) or (b). It has a mid-efficient furnace rated at 150 MBtu/h and a hot water tank with an input of 40 MBtu/h. The furnace has no draft control device, but the hot water tank is equipped with a draft-hood. The air supply is from outdoors. Determine the area of air supply duct.", options: [ "4 in²", "14 in²", "29 in²", "18 in²" ], correct: 1 }, { question: "A structure does not comply with Clause 8.2.1(a) or (b). It is equipped with a boiler rated at 150 MBtu/h and a hot water tank rated at 60 MBtu/h. Both appliances are equipped with draft control devices. The volume of the structure is 8000 cu ft. Determine the area of air supply duct.", options: [ "16 in²", "29 in²", "32 in²", "None required" ], correct: 2 }, { question: "A structure does not conform to Clause 8.2.1(a) or (b). It is equipped with a boiler rated at 225 MBtu/h and a hot water tank rated at 50 MBtu/h. Both appliances do not use a draft control device and the volume of the structure is 10 000 cu ft. Determine the area of air supply duct.", options: [ "20in²", "32 in²", "40 in²", "None required" ], correct: 3 }, { question: "A boiler room is located within an enclosure in a structure that does not comply with Clause 8.2.1(a) or (b). The boiler is rated at 200 MBtu/h and a hot water tank is rated at 60 MBtu/h. Both units are equipped with draft-hoods. The volume of the structure is 20 000 cu ft and Table 8.3 indicates that the air supply may be taken from the structure. Calculate the area of openings required to be cut into the enclosure.", options: [ "20in²", "260 in² upper and lower", "260 in² upper opening only", "260 in² lower opening only" ], correct: 1 }, { question: "A mechanical room is equipped with gas appliances with a total input of 1800 MBtu/h. All appliances are equipped with draft control devices. Determine the free area of air supply opening.", options: [ "18 in²", "60 in²", "201 in²", "260 in²" ], correct: 2 }, { question: "A structure is equipped with a boiler rated at 400 MBtu/h and a hot water tank rated at 80 MBtu/h. Both pieces of equipment are equipped with draft control devices and the air supply is ducted from outdoors. Determine the free area of ventilation opening", options: [ "7 in²", "10 in²", "12 in²", "68 in²" ], correct: 1 }, { question: "A structure is equipped with a boiler rated at 1000 kW and has a barometric draft control. Determine the free area of air supply opening.", options: [ "70,000 mm²", "201,500 mm²", "310,000 mm²", "None required" ], correct: 1 }, { question: "A structure is equipped with appliances rated at 2000 MBtu/h. None of the appliances are equipped with draft control devices. Determine the free area of air supply opening.", options: [ "10in²", "67 in²", "214 in²", "285 in²" ], correct: 2 }, { question: "A structure is equipped with appliances rated at 600 kW of input. The appliances do not have any draft control devices and the air is supplied from outside. Determine the free area of air supply opening", options: [ "42,000 mm²", "93,000 mm²", "139,500 mm²", "310,000 mm²" ], correct: 2 }, { question: "A structure has a mechanical room into which air must be ducted from outdoors. It contains the following appliances: One boiler rated at 1200 MBtu/h, equipped with a barometric damper. Two duct heaters without draft controls rated at 600 MBtu/h each. Two hot water tanks rated at 300 MBtu/h each. Both tanks are equipped with draft-hoods. Determine the free area of air supply opening", options: [ "80 in²", "171 in²", "220 in²", "240 in²" ], correct: 3 }, { question: "Calculate the air requirements supplied from outdoors to a mechanical room equipped with the following appliances: One boiler with a draft control at 200 kW. One boiler with no draft control rated at 100 kW. Two duct heaters with no draft control rated at 50 kW each. Two hot water tanks with draft-hoods at 100 kW each. Determine the free area of ventilation opening", options: [ "4,200 mm²", "11,250 mm²", "12,250 mm²", "13,950 mm²" ], correct: 2 } ] }, finalExam: { title: "CSA Unit 22 Final Exam - Venting Systems", questions: [ { question: "What is a forced draft?", options: [ "Draft produces by mechanical device downstream from the combustion zone.", "Draft produces by mechanical device upstream from the combustion zone.", "Draft produces by the upward movement of hot gases, creating a negative pressure.", "A condition in which a draft is forced downward and can cause flue gas spillage." ], correct: 1 }, { question: "What is an induced draft?", options: [ "Draft produces by mechanical device downstream from the combustion zone.", "Draft produces by mechanical device upstream from the combustion zone.", "Draft produces by the upward movement of hot gases, creating a negative pressure.", "A condition in which a draft is forced downward and can cause flue gas spillage." ], correct: 0 }, { question: "Which vent type is capable of withstanding the highest flue gas temperature?", options: [ "Type A vent", "Type B vent", "Type C vent", "Type L vent" ], correct: 0 }, { question: "What is the maximum input of an appliance being vented through an exhaust canopy?", options: [ "12 kW", "40 kW", "120 kW", "400 kW" ], correct: 2 }, { question: "How are the joints on a C-vent secured?", options: [ "Gear clamps", "Three screws", "Locking bands", "Solvent cement" ], correct: 1 }, { question: "Which category of appliance can be vented using the Annex C Code tables?", options: [ "Category I", "Category II", "Category III", "Category IV" ], correct: 0 }, { question: "When reducing the size of a vent connector from that of the draft-hood, what is the minimum total vent height required?", options: [ "5 ft", "10 ft", "15 ft", "20 ft" ], correct: 1 }, { question: "A single vented fan-assisted appliance requires 3 elbows for the vent connector. How will the table capacity need to be adjusted?", options: [ "Reduced by 5%", "Reduced by 10%", "Reduced by 15%", "Reduced by 25%" ], correct: 2 }, { question: "What is the most serious and hazardous venting problem?", options: [ "Corrosion", "Condensation", "Flue gas spillage", "Insufficient support" ], correct: 2 }, { question: "What is the most common cause of flue gas spillage on Category I appliances?", options: [ "Building depressurization", "Improper vent configuration", "Incorrectly sized venting system", "Blocked or restricted venting system" ], correct: 0 }, { question: "How are air supply requirements for a direct vent appliance determined?", options: [ "Table 8.1", "Table 8.2", "Code clause 8.2.6", "Manufacturer's literature" ], correct: 3 }, { question: "What is the minimum required free area of a square combustion air opening?", options: [ "3 in²", "6 in²", "9 in²", "10 in²" ], correct: 2 }, { question: "What combination will give the greatest draft?", options: [ "Lowest stack temperature, highest outdoor air temperature and shortest vent.", "Highest stack temperature, lowest outdoor air temperature and highest vent.", "Highest stack temperature, highest outdoor air temperature and highest vent.", "Lowest stack temperature, lowest outdoor air temperature and lowest vent." ], correct: 1 }, { question: "To extract heat from flue gases, what would be installed?", options: [ "A condenser", "A heat reclaimer", "A heat exchanger", "Heat recovery unit" ], correct: 1 }, { question: "What is the maximum vent gas temperature for Type L vents?", options: [ "90°C (195°F)", "110°C (230°F)", "243°C (470°F)", "288°C (550°F)" ], correct: 3 }, { question: "What type of BH vent is CPVC?", options: [ "Class I", "Class II A", "Class II B", "Class II C" ], correct: 2 }, { question: "What is the minimum height a chimney must terminate above a flat roof?", options: [ "450 mm", "600 mm", "900 mm", "1500 mm" ], correct: 2 }, { question: "A single fan-assisted furnace may be vented into a tile lined masonry chimney.", options: [ "True", "False" ], correct: 1 }, { question: "When the vent table permits more than one diameter of pipe that can be used for a connector or the vent, which is preferred: the larger or the smaller?", options: [ "Larger connector or vent", "Smaller connector or vent", "Smaller connector and larger vent", "Larger connector and smaller vent" ], correct: 1 }, { question: "What is the purpose of a spill switch?", options: [ "Sense a gas leak", "Sense a blocked vent", "Sense a water supply leak", "Signal water pressure relief valve activation" ], correct: 1 }, { question: "What is the smallest opening dimension in a fixed louvre, grille, or screen?", options: [ "1/8\"", "1/4\"", "1/2\"", "1\"" ], correct: