ICE EXAM QUESTIONS AND ANSWERS
When setting up the outdoor unit what could water dripping from the roof cause the unit
to do in the winter time? - Answers- Could cause the condenser fan blades to freeze up
when operating in heating mode.
Why must you allow proper draining at the base of the condenser heat pump ? -
Answers- To prevent ice build up at the base of the condenser that could cause damage
to the copper/ aluminum coils.
Why must you follow the installation manual's installation clearance when installing an
air handler? - Answers- To ensure adequate room for servicing the units and also
allows for proper airflow through the equipment when needed.
Sheet metal often uses what procedure to stiffen the duct and keep it from flexing. -
Answers- Cross Break
What is the typical airflow required for comfort cooling systems? - Answers- 400 CFM
per ton of refrigerant
As external static pressure rises, the furnace blower's ability to move air does what? -
Answers- Declines
Most residential furnaces are designed to deliver their rated airflow up to? - Answers- .5
inches wc total external static pressure.
The CFM of an air distribution system can be figured several different ways. The
velocity method uses what formula? - Answers- CFM=duct opening size (measured in
Square Feet) X Velocity( measured in FPM).
what do you use to cut round circles in sheet metal duct? - Answers- Aviation snips
how do you measure the pressure in a duct system? - Answers- Total Pressure= Static
Pressure + Velocity Pressure
How do you use a multi tap transformer ? - Answers- with black being common in most
cases you will make sure to choose either the 115 volt wire, the 208 wire or the 240
wire.
what is used to measure Velocity Pressure in a Duct System by pointing the tube into
the air - Answers- The Pitot Tube
what is used to check for a pressure drop across filters or coils. - Answers- the incline
Manometer
, A Heat Pump with too little return air will cause what to your pressures in the heating
operation? - Answers- Will cause higher than normal head pressure in the heating
mode.
What must be done when charging refrigerant into the system? - Answers- Never
guess when charging a HVAC system. always weight refrigerant into the system using
digital scales.
On a single phase compressor what will be the highest resistance (ohm) reading -
Answers- between the start and run windings
On a single phase compressor what is the middle resistance or ohm readings? -
Answers- between the start and common pins
On a single phase compressor what is the lowest resistance or ohm readings? -
Answers- between the common and run pins on a compressor
What problem restricts the proper quantity of heat to be available to boil the low
pressure/temperature liquid to a vapor and will eventually cause compressor failure due
to liquid refrigerant flood back. - Answers- Lower than normal air flow through the
evaporator of an Air Conditioning System
What is used to prevent vibration from fan onto duct work and connects ductwork to the
air handler? - Answers- Flexible canvas connectors
A restrictions in the duct system such as undersized duct, dirty filters or evaporator coil,
or closed or blocked registers will cause what? - Answers- the external static pressure
to rise
When the bearings in a compressor begin to wear out what will the RLA (running load
amps) start to do? - Answers- The RLA will increase and start running higher than
normal amps.
What is the purpose of the start capacitor on a motor? - Answers- to increase starting
torque
When doing a pressure test on the filter drier what should be the maximum pressure
(psig) drop? - Answers- 3 psig of pressure
What will a dirty return air filter cause your pressure and air flow to do? - Answers- It
will cause low air flow across the evaporator causing your superheat the lower due to
less heat being available to raise the vapor temperature above the saturation
temperature.
When setting up the outdoor unit what could water dripping from the roof cause the unit
to do in the winter time? - Answers- Could cause the condenser fan blades to freeze up
when operating in heating mode.
Why must you allow proper draining at the base of the condenser heat pump ? -
Answers- To prevent ice build up at the base of the condenser that could cause damage
to the copper/ aluminum coils.
Why must you follow the installation manual's installation clearance when installing an
air handler? - Answers- To ensure adequate room for servicing the units and also
allows for proper airflow through the equipment when needed.
Sheet metal often uses what procedure to stiffen the duct and keep it from flexing. -
Answers- Cross Break
What is the typical airflow required for comfort cooling systems? - Answers- 400 CFM
per ton of refrigerant
As external static pressure rises, the furnace blower's ability to move air does what? -
Answers- Declines
Most residential furnaces are designed to deliver their rated airflow up to? - Answers- .5
inches wc total external static pressure.
The CFM of an air distribution system can be figured several different ways. The
velocity method uses what formula? - Answers- CFM=duct opening size (measured in
Square Feet) X Velocity( measured in FPM).
what do you use to cut round circles in sheet metal duct? - Answers- Aviation snips
how do you measure the pressure in a duct system? - Answers- Total Pressure= Static
Pressure + Velocity Pressure
How do you use a multi tap transformer ? - Answers- with black being common in most
cases you will make sure to choose either the 115 volt wire, the 208 wire or the 240
wire.
what is used to measure Velocity Pressure in a Duct System by pointing the tube into
the air - Answers- The Pitot Tube
what is used to check for a pressure drop across filters or coils. - Answers- the incline
Manometer
, A Heat Pump with too little return air will cause what to your pressures in the heating
operation? - Answers- Will cause higher than normal head pressure in the heating
mode.
What must be done when charging refrigerant into the system? - Answers- Never
guess when charging a HVAC system. always weight refrigerant into the system using
digital scales.
On a single phase compressor what will be the highest resistance (ohm) reading -
Answers- between the start and run windings
On a single phase compressor what is the middle resistance or ohm readings? -
Answers- between the start and common pins
On a single phase compressor what is the lowest resistance or ohm readings? -
Answers- between the common and run pins on a compressor
What problem restricts the proper quantity of heat to be available to boil the low
pressure/temperature liquid to a vapor and will eventually cause compressor failure due
to liquid refrigerant flood back. - Answers- Lower than normal air flow through the
evaporator of an Air Conditioning System
What is used to prevent vibration from fan onto duct work and connects ductwork to the
air handler? - Answers- Flexible canvas connectors
A restrictions in the duct system such as undersized duct, dirty filters or evaporator coil,
or closed or blocked registers will cause what? - Answers- the external static pressure
to rise
When the bearings in a compressor begin to wear out what will the RLA (running load
amps) start to do? - Answers- The RLA will increase and start running higher than
normal amps.
What is the purpose of the start capacitor on a motor? - Answers- to increase starting
torque
When doing a pressure test on the filter drier what should be the maximum pressure
(psig) drop? - Answers- 3 psig of pressure
What will a dirty return air filter cause your pressure and air flow to do? - Answers- It
will cause low air flow across the evaporator causing your superheat the lower due to
less heat being available to raise the vapor temperature above the saturation
temperature.
