Podcast
Questions and Answers
What is the correct pressure and temperature setting for a temperature-pressure (T/P) relief valve on a domestic 60-gallon hot water tank?
What is the correct pressure and temperature setting for a temperature-pressure (T/P) relief valve on a domestic 60-gallon hot water tank?
- 100 psi and 210 degrees Fahrenheit
- 150 psi and 210 degrees Fahrenheit (correct)
- 125 psi and 180 degrees Fahrenheit
- 210 psi and 150 degrees Fahrenheit
Which of the following best describes the primary function of a gas meter?
Which of the following best describes the primary function of a gas meter?
- To detect and alert to gas leaks in the piping system
- To accurately measure gas consumption for billing purposes (correct)
- To provide a visual indication of gas flow rate
- To regulate the gas pressure entering a building
In a combustion limit control system, at approximately what temperature does the blower fan typically shut off?
In a combustion limit control system, at approximately what temperature does the blower fan typically shut off?
- 127 degrees Fahrenheit
- 130 degrees Fahrenheit (correct)
- 200 degrees Fahrenheit
- 100 degrees Fahrenheit
What is the approximate BTU (British Thermal Unit) gas input for a 25 horsepower (Hp) steam boiler?
What is the approximate BTU (British Thermal Unit) gas input for a 25 horsepower (Hp) steam boiler?
What is the closest approximate oil nozzle size in gallons per hour (gph)?
What is the closest approximate oil nozzle size in gallons per hour (gph)?
Which of the following is a defining characteristic of a condensing warm air furnace?
Which of the following is a defining characteristic of a condensing warm air furnace?
What is the maximum high limit setting for a gravity furnace, ensuring safe and efficient operation?
What is the maximum high limit setting for a gravity furnace, ensuring safe and efficient operation?
According to safety regulations, how far should a vent terminate from a window when the appliance-firing rate is 65 MBtu/h?
According to safety regulations, how far should a vent terminate from a window when the appliance-firing rate is 65 MBtu/h?
When evaluating the efficiency of an appliance, it is crucial to ensure the appliance does not fall below what percentage of its rated input?
When evaluating the efficiency of an appliance, it is crucial to ensure the appliance does not fall below what percentage of its rated input?
In which scenario is it mandatory to conduct a high-pressure leak test when working on a gas piping system?
In which scenario is it mandatory to conduct a high-pressure leak test when working on a gas piping system?
What mechanism provides the closing force in a 2-inch gas regulator, ensuring it can effectively control gas flow?
What mechanism provides the closing force in a 2-inch gas regulator, ensuring it can effectively control gas flow?
Which type of boiler is correctly identified as a Scotch marine boiler?
Which type of boiler is correctly identified as a Scotch marine boiler?
In the B149.1 codebook, which section provides specifications and guidelines for installing a dirt pocket in a gas piping system?
In the B149.1 codebook, which section provides specifications and guidelines for installing a dirt pocket in a gas piping system?
What is the minimum area required around an appliance to ensure adequate space for servicing and maintenance?
What is the minimum area required around an appliance to ensure adequate space for servicing and maintenance?
Is a 2-inch diameter round duct permissible for use as combustion supply air for an appliance under typical conditions?
Is a 2-inch diameter round duct permissible for use as combustion supply air for an appliance under typical conditions?
When condensation forms on the inside of a window as the outdoor temperature drops, how should the humidistat setting be adjusted to address the issue?
When condensation forms on the inside of a window as the outdoor temperature drops, how should the humidistat setting be adjusted to address the issue?
On which component is an adjustable sheave pulley most commonly used to change the speed of a blower?
On which component is an adjustable sheave pulley most commonly used to change the speed of a blower?
In a one-pipe hydronic heating system, what type of component is specifically designed to redirect water flow to different heating zones or circuits?
In a one-pipe hydronic heating system, what type of component is specifically designed to redirect water flow to different heating zones or circuits?
What is the most direct effect of increasing the size of a blower pulley in a forced-air heating system?
What is the most direct effect of increasing the size of a blower pulley in a forced-air heating system?
Flashcards
T/P relief valve setting
T/P relief valve setting
The setting is typically 150 psi and 210 degrees Fahrenheit for a domestic 60-gallon hot water tank.
Gas meter function
Gas meter function
The main function is to measure gas input for billing purposes.
Blower fan cutoff temperature
Blower fan cutoff temperature
The blower fan typically turns off at 100 degrees Fahrenheit on a combustion limit control.
BTU gas input for 25 Hp boiler
BTU gas input for 25 Hp boiler
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Condensing furnace heat exchangers
Condensing furnace heat exchangers
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Gravity furnace high limit
Gravity furnace high limit
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Vent distance from window
Vent distance from window
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Appliance rated input
Appliance rated input
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High-pressure leak test necessity
High-pressure leak test necessity
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Gas regulator closing force
Gas regulator closing force
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Scotch marine boiler type
Scotch marine boiler type
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Fire tube boiler structure
Fire tube boiler structure
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Most important valve
Most important valve
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Fuse circuit rating limit
Fuse circuit rating limit
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Vapour barrier location
Vapour barrier location
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Air for final combustion
Air for final combustion
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Generator
Generator
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Condenser function
Condenser function
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Natural gas vs propane refigerator
Natural gas vs propane refigerator
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CO level
CO level
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Study Notes
- T/P relief valve setting on a domestic 60-gallon hot water tank is 150 psi and 210 degrees Fahrenheit.
- The main function of a gas meter is consumption of gas for billing.
- On a combustion limit control, the blower fan turns off at 130 degrees Fahrenheit.
- The BTU gas input of a 25 Hp steam boiler is 850 cfh.
- The approximate oil nozzle size is 5.8 gph.
- A condensing warm air furnace has two heat exchangers.
- The maximum high limit setting for a gravity furnace is 350 degrees Fahrenheit.
- A vent should terminate 36 inches from a window if the appliance-firing rate is 65 MBtu/h.
- An appliance should not exceed the rated input less than 90%.
- A high-pressure leak test should be performed if a section of more than 20 feet is added to an existing gas piping system.
- The closing force of a 2' gas regulator is downstream pressure.
- A scotch marine boiler is a fire tube boiler.
- Specs on a dirt pocket can be found in section #6 of the B149.1 codebook.
- The minimum area needed to service an appliance is 36 in x 36 in.
- A 2 in. diameter round duct cannot be used as combustion supply air to an appliance.
- If condensation occurs on the inside of the window when the outdoor temperature drops, the humidistat should be decreased
- An adjustable sheave pulley is most commonly used on a blower shaft.
- Diverter valves are used to redirect water in a one pipe hydronic-heating system.
- Increasing the size of a blower pulley increases air flow.
- Disposable filters should never be cleaned, but replaced.
- The humidistat control setting in the summer time should be 0%.
- If the cooling coil gets too dirty, the supply airflow on the furnace will decrease.
- The device that the water tank uses to direct the incoming water to the lower part of the tank is called a "dip tube".
- Expansion tanks provide a place for water to travel and allow for pressure fluctuations in the system.
- Steel boilers are generally classified as fire tube boilers.
- A fire tube boiler has water outside and tubes and flue gases inside.
- The most important valve in a hot water system is a relief valve.
- Closing up the motor pulley is the best way to increase the furnace blower speed.
- The vent of a direct vent propane appliance shall not terminate less than 3 ft from a gas service regulator or within 3 ft of a mechanical air supply inlet to a building
- Fuse circuits rating must not exceed the current rating of the conductor that they are connected to.
- Glass plug type fuses must be replaced after blowing.
- As the length of a conductor increases, it may be necessary to increase the wire size.
- Armored cable is referred to as BX.
- If a relay coil designed "82” is energized, will cause all R2 contacts to change position.
- Clamp-on ammeters are connected in parallel with the device being checked.
- A 240-volt power supply for a residential electrical circuit is taken from the line side of one branch circuit breaker and the line side of the second breaker.
- The open circuit test reading of a thermocouple should be in the range of 25 to 30 mV.
- A temperature control with a narrow differential will cause a very close temperature control and long "on" cycles.
- Thermostat heat anticipators are normally connected in series with the valve and in series with the thermostat contacts.
- If the heat anticipator of a thermostat is set low, a probable condition would be short cycling of the main burner.
- A poorly insulated building could result in increased fuel consumption.
- Increasing the amount of attic ventilation in a building will lower the indoor dry bulb temperature.
- Vapor barriers should be installed on the warm side of the insulation.
- With respect to heat loss, the most important area to seal against air leaks is around the windows.
- If air for combustion comes from inside the house, it is replaced with outside air by infiltration.
- The best way to insulate an attic is to install expanding foam insulation and add vapour barrier.
- A correctly sized air intake ensures dilution air and combustion requirements.
- An air supply opening from the outdoors shall be located not less than 12 inches above the outside grade level.
- Negative pressure in a building is caused when the volume of the air leaving the building exceeds the volume of air entering the building
- The voltage of a glow-coil is 120VAC
- Moisture exhaust ducts should never be screwed together.
- The major disadvantage of a direct modulating over control is that the oven temperature cannot be maintained below approximately 250 degrees Fahrenheit.
- The generator used in gas fired refrigerator takes the place of a compressor in a mechanical refrigeration system.
- In a 3 way refrigerator, the sources that may be used to achieve cooling are 120VAC, 12VDC, propane.
- The condenser serves to expels heat that has been gathered from inside the refrigerator.
- The absorber removes heat from inside the refrigerator.
- The evaporator removes heat from inside the refrigerator.
- The generator provides the heat energy source that begins and maintains the operating cycle on gas fired refrigerators.
- If a gas fired refrigerator is not kept level, liquid ammonia will accumulate in sections of the evaporator
- Placing more heat on the generator causes more refrigeration affect
- The effect on the refrigeration cycle when the flame on a gas fired refrigerator is at the lowest or minimum setting is less refrigeration affect
- The only physical difference between a natural gas and propane-fired refrigerator is orifice size.
- Direct vent type gas-fired refrigerators are approved for use in a recreational vehicle.
- 120 volt AC form of power may not be used on a vehicle refrigerator when the vehicle is in motion.
- In a gas-fired refrigerator, a level should be placed on the top row of the evaporator fins.
- A gas-fired refrigerator should be defrosted when the ice buildup reaches 50% of the space between the evaporator fins
- Gas-fired refrigerators should be cleaned twice a year.
- Use caution not to enlarge the gas orifice when cleaning and maintaining the gas fired refrigerator.
- Always check the level of carbon monoxide in the flue products whenever service or repair is performed on a gas-fired refrigerator.
- A refrigerant leak on a gas-fired refrigerator is usually indicated by a yellow liquid substance.
- A category I appliance is a non-condensing appliance with a non-positive vent static with a flue loss of not less than 17%
- Air for combustion of natural gas for every 1,000 Btu produced is 10 cubic ft
- There are additional requirements of excess for dilution of none of the above
- Natural draft is defined as the draft developed by the difference in the temperature of hot gases and outside atmosphere: true draft vent relies on upward movement of gases.
- The draft will be greatest when all of the above
- average stack temperature is highest
- the outdoor air temperature is least
- the stack height is greatest
- Downdraft at the draft diverter is false on natural gas:
- The venting system will operate because there is a draft
- A fire grille is not a component of a venting system when type-B vent is used?
- Components used for a B vent system should be manufactured and not altered in any manner: this is true
- On an appliance with forced air, draft is produced upstream of combustion zone with mechanical device
- NAT+NAT — refers to the maximum combined input rating two or more draft hoods connected to a common vent: this is true.
- FAN Min - refers to the maximum appliance output rating of a category 1 appliance with a fan assisted combustion: this is false.
- The use of a smaller vent size than the appliance draft hood outlet is prohibited
- A vent connector serving a single appliance with a single flu outlet can be smaller than the vent as long as it is connected to a draft hood outlet of equivalent size? This is false
- An appliance installed in a dwelling unit shall not be connected to a flue serving both solid fuelled appliance and a solid fuelled fireplace unless the opening from the fireplace to the flue is permanently sealed
- Vent and Chimney requirements for a Type B, BH, or L vents or factory built chimneys used for venting an appliance shall be installed according to code
- When a confined space is used for return air, it shall not contain a vent or connector that does not have sealed joints: This is true
- A vent less than ten feet from any wall on a roof must locate the rain cap at least 3 feet above the wall: this is false
- A vent shall not terminate all of the above
- directly above a paved sidewalk or driveway that is located between single dwelling and serves both dwellings
- within 3 feet of any gas service regulator
- within 6 feet of a mechanical air supply
- Secondary air is for intermediate and final stages of combustion downstream of ignition
- A draft control device is a draft hood or draft regulator
- When Type B vent passes through a floor or ceiling, good venting practice dictates the use of a fire stop spacer
- A return air duct opening can be installed in the same room as the forced warm air furnace is false
- Electrically operated automatic dampers shall be interlocked, so that the main burner cannot operate unless the dampers are in the fully open position.
- When a chimney liner is installed the clean out door at the base of the chimney will be cemented shut
- Mechanical flue exhausters may be used in vents or chimneys in lieu of natural draft, except for building used as one or two family dwellings
- Single wall vent type of vent connector may be used between the draft hood inlet and the flue outlet of a converted furnace?
- The following statements is correct: you can use a power exhauster in place of natural draft venting in a residential home if you also install an air proving switch
- When using a liner inside a chimney, it must extend from inside the space where the appliance is located to the top of the chimney
- Standard rule for sizing either a vent or a chimney, which will vent more than one appliance is the area of the common vent is to equal the area of the largest draft control device outlet or the largest flue outlet plus 50% the area of the sum of the outlet areas of the additional appliances
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