Study guides, Class notes & Summaries

HVAC Gas Heat certification exam Questions and Answers 100% Pass A gas furnace is to be installed in a garage. The national standards require that the burners and ignition sources must be located ______ above the floor - Correct Answer ️️ -18 inches A good description of how a bi-metal fan switch operates the blower motor on a gas furnace is - Correct Answer ️️ -Temperature on- temperature off Redundant gas valves used on gas furnaces have - Correct Answer ️️ -Dual gas shut o...

A gas furnace is to be installed in a garage. The national standards require that the burners and ignition sources must be located ______ above the floor : 18 inches A good description of how a bi-metal fan switch operates the blower motor on a gas furnace is : Temperature on- temperature off Redundant gas valves used on gas furnaces have : Dual gas shut off seats Burning one cubic foot of liquefied petroleum gas completely will produce approximately ______ BTUs : LP gas has a spe...

What is an SSU and what does it do? : It is a unit located on the side of the first which receives power (120 volts) before anything located within the furnace itself. It primarily consists of a switch and a fuse, and it is what allows for power to flow to the door switch. Opening the switch on the SSU will cut power to everything within the furnace. What is an OCPD? Describe its function in detail. : An OCPD is an Over-Current Protection Device, and it will protect conductors and equ...

An instrument that measures potential differences between 2 points in an electrical circuit is called? A. potentiometer B. thermistor C. ohmeter D. voltmeter : voltmeter This device uses a thermal sensing bulb at the outlet of the evaporator to sense temperature and control superheat A. automatic expansion valve B. thermostatic expansion valve C. low side float D. schraeder valve : thermostatic expansion valve 2 | P a g e when installing a reversing valve on a heat pump, how man...

Propane and Butane are _______ than air: : Heavier What will be the resistance in the circuit if the supply voltage is 30V and current flowing through the circuit is 5A : 6 ohms Temperature at which oil starts to produce a waxy substance that may interfere with the refrigeration system : Floc point What manifold gauge set is used to charge, evacuate, add oil and recover refrigerant from a refrigeration and air conditioning system? : Yellow hose

Current flow is : the flow of electrons in the circuit impedance is : opposition to alternating current flow like charges : repel each other Any material that will readily release electrons is called : a conductor the symbol for current is : I Which of the following materials would best be suited for use as a semi-conductor : silicone 2 | P a g e the safety ground conductor is usually color coded : black (or bare or green & yellow stripe) An electron has : a negative charge resi...

Can cause a packaged HVAC unit to run high head pressure? : The condenser coil is dirty. Condenser coil fins are often damaged by: : Hail storms. Frequent pressure washing. Salt spray. Insufficient rinsing after cleaning coils with strong acids and bases. Water cooled air conditioning systems: : Use building furnished water at a temperature of approximately 80°F to transfer heat from water

Heat which causes a change in temperature of a substance is called : Sensible Heat Heat added to a substance without a rise in temperature is called : Latent Heat Heat added to refrigerant in a vapor state after the evaporation process is called : Superheat A scroll compressor moved refrigerant by means of : Involute spirals The movement of heat by way of fluid is called : Convection The movement of heat through a solid object is called : Conduction 2 | P a g e The standard unit for...

using an ohmmeter, there is 120 VAC between high speed and ground wires, this indicates : open if temperature rise is too high... : increase fan speed how many of the 3 OSHA conditions defining confined spaces must be met : all 3 what causes the temperature limit safety switch to shut off the burner : fan motor failure flashback indicates : the gas is flowing slower than the speed at which burn is occurring what type of connector is used to control noise in ductwork 2 | P a g e : v...

The International Mechanical Code considers a "flammable Vapor" to be concentration of flammable constituents in the air which exceeds _____________ percent of its flammability limit. : 25% During installation or service of electrical controls, a digital multimeter set to voltage must be connected in what manner? : In parallell Unvented fuel-burning room heaters are NOT permitted in a Group ___________ occupancy? : A According to the Code, smoke detectors shall be installed in re...

Heat which causes a change in temperature of a substance is called; : Sensible Heat. heat added to substance without a rise in temperature; (example: liquid refrigerant to gas) this process is called? : Latent heat of vaporization. Heat added to the refrigerant in a vapor state after the evaporation process is called; : Superheat. A scroll compressor move refrigerant by means of; : Involute Spirals. The movement of heat by way of fluid (or air) is called; : Convection. The movement o...