g2 exam
Relative humidity is defined as? - ANS-The percentage of moisture that the quantity of
air is holding in relation to how much it can hold
A certified hose can be used to connect a construction heater to a gas piping system for
temporary use when? - ANS-When 1/4 turn level type shut off is installed upstream of
the hose
What is the minimum amount of insulation required behind the vapour barrier? -
ANS-2/3
The vent connector and common vent of a water heater and furnace are tied together
with a "Y" fitting before entering the chimney. Note the information below and answer
the question that follows.
Chimney - H= 25'
Furnace - 100,000 Btuh
Single wall vent
Mid-efficiency with induced draft blower
Water Heater - 45,000 Btuh
Single wall vent
Draft diverter
Home - 25 years old
No sealed vapour barrier
Has range hood, bathroom fan and fireplace
Volume =4,000 cubic feet
What is the maximum lateral length of the common vent lateral?
Incorrect Response
6 feet - ANS-9 feet
Fan assist burners will: - ANS-Overcome the resistance of the burner only
, When twinning two domestic water heaters: - ANS-The supply and discharge piping
must be identical in length and resistance
Which type of venting system may be used on a fireplace insert? - ANS-Certified
chimney liner
A low gas pressure switch must interrupt the flow of gas when? - ANS-When the
pressure drops more than 50% of the proper supply pressure
What is the effect on the refrigeration cycle, when the flame on a gas fired refrigerator is
at the lowest or minimum setting? - ANS-No refrigeration affect
What is the minimum distance above grade level a dryer vent can terminate? - ANS-12"
What is the preferred material for moisture exhaust duct for a gas dryer? - ANS-Rigid
metal
What is the purpose of the water reducing valve? - ANS-To reduce the incoming make
up water to the boiler to 12 PSI from city water pressure
Which type of venting system may be used on a concealed wall furnace? - ANS-Type
BW
Which of the following causes negative pressure in a building? - ANS-Insufficient supply
of makeup and combustion air
If a crack is located in a residential furnace, what steps should the technician take? -
ANS-Inform customer, notify gas utility verbally immediately, notify gas utility in writing
within 14 days, shut off gas to appliance
The maximum steam pressure allowed on a low pressure steam boiler is? - ANS-10 PSI
What is the best way to ventilate a building? - ANS-Install a Heat Recovery Ventilator
(HRV)
The "W" terminal on a furnace control board performs what purpose? - ANS-To energize
the gas valve on a call for heat
What types of gas fired refrigerators are approved for use in a recreational vehicle? -
ANS-Approved direct vent type
Relative humidity is defined as? - ANS-The percentage of moisture that the quantity of
air is holding in relation to how much it can hold
A certified hose can be used to connect a construction heater to a gas piping system for
temporary use when? - ANS-When 1/4 turn level type shut off is installed upstream of
the hose
What is the minimum amount of insulation required behind the vapour barrier? -
ANS-2/3
The vent connector and common vent of a water heater and furnace are tied together
with a "Y" fitting before entering the chimney. Note the information below and answer
the question that follows.
Chimney - H= 25'
Furnace - 100,000 Btuh
Single wall vent
Mid-efficiency with induced draft blower
Water Heater - 45,000 Btuh
Single wall vent
Draft diverter
Home - 25 years old
No sealed vapour barrier
Has range hood, bathroom fan and fireplace
Volume =4,000 cubic feet
What is the maximum lateral length of the common vent lateral?
Incorrect Response
6 feet - ANS-9 feet
Fan assist burners will: - ANS-Overcome the resistance of the burner only
, When twinning two domestic water heaters: - ANS-The supply and discharge piping
must be identical in length and resistance
Which type of venting system may be used on a fireplace insert? - ANS-Certified
chimney liner
A low gas pressure switch must interrupt the flow of gas when? - ANS-When the
pressure drops more than 50% of the proper supply pressure
What is the effect on the refrigeration cycle, when the flame on a gas fired refrigerator is
at the lowest or minimum setting? - ANS-No refrigeration affect
What is the minimum distance above grade level a dryer vent can terminate? - ANS-12"
What is the preferred material for moisture exhaust duct for a gas dryer? - ANS-Rigid
metal
What is the purpose of the water reducing valve? - ANS-To reduce the incoming make
up water to the boiler to 12 PSI from city water pressure
Which type of venting system may be used on a concealed wall furnace? - ANS-Type
BW
Which of the following causes negative pressure in a building? - ANS-Insufficient supply
of makeup and combustion air
If a crack is located in a residential furnace, what steps should the technician take? -
ANS-Inform customer, notify gas utility verbally immediately, notify gas utility in writing
within 14 days, shut off gas to appliance
The maximum steam pressure allowed on a low pressure steam boiler is? - ANS-10 PSI
What is the best way to ventilate a building? - ANS-Install a Heat Recovery Ventilator
(HRV)
The "W" terminal on a furnace control board performs what purpose? - ANS-To energize
the gas valve on a call for heat
What types of gas fired refrigerators are approved for use in a recreational vehicle? -
ANS-Approved direct vent type
