HVAC CONTRACTOR EXAM COMPLETE SOLUTIONS

HVAC CONTRACTOR EXAM COMPLETE SOLUTIONS 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 when installing a reversing valve on a heat pump, how many brazed joints should be made? a. 3 b. 5 c. 4 d. 2 ️4 what would not be considered a misuse of a contractors license? a. advertising under mulitple names b. employing service technicians to work under their license c. loaning license to more than one company d. continue to work on an expired license ️employing service technicians to work under their license what is used to prevent microbiological growth and help "dirty socky syndrome? a. radiation b. ultraviolet light c. electrostatic filters d. heat rated static filters ️ultraviolet light a precisely sized drilled hole through which gas flows from the manifold to the burner is known as what a. spud b. drill size c. orifice d. dimple ️orifice rooftop package hvac units utilize economizers for what primary purpose? a. to exhaust extra indoor air b. to equalize indoor/outdoor pressures c. to allow outside air to be used for cooling in mild weather d. to raise indoor relative humidity ️to allow outside air to be used for cooling in mild weather what is the minimum gauge required for a 12" galvanized steel connector used to connect a lows heat appliance? a. .019 b. .029 c. .034 d. .2 ️.029 after cutting pipes they must be reamed for what purpose? a. to clean pipe threads b. to smooth the end of the pipe c. to remove burrs and chips from the inside d. to help the threading process ️to remove burrs and chips from the inside in manual d what is the suggested friction (IWC) loss for hand dampers? a. .01 b. .08 c. .1 d. .03 ️.03 a system with a 120 degree saturation temperature in the condenser with R-22 has a liquid line temperature of 105 degrees. what does the temperature difference of 15 degrees represent? a. superheat b. wet bulb c. subcooling d. air temperature difference ️subcooling when a technician uses a nitrogen cylinder to pressurize a system for leak detection what should be used for safety a. hand valve b. impervious gloves c. pressure regulator d. temperature gauge ️pressure regulator when the azeotropic blend of refrigerant condenses or evaporates at a different temperature, it is called? a. fractionation b. segregation c. purification d. latent heat of fusion ️fractionation before brazing copper tubing what should be circulated through the tubing first a. CO b. refrigerant c. oil d nitrogen ️nitrogen a service technician should adjust the superheat setting on a TXV how often a. never b. when absolutely necessary c. once a month d. routinely ️when absolutely necessary refer to house 1drawing. calculate the net summer heat gain through the east exterior wall of bedroom 1. select the closest answer a. 115 btuh b. 338 btuh c. 326 btuh d. 1234 btuh ️115 btuh gas fitting installed in concealed locations shall be limited to which of the following a. threaded elbows b. tees c. couplings d. all of the above ️all of the above recovered refrigerant may only be reused under what condition a. when it has been purified to meet ARI 700 standards b. when it is used in the equipment is was removed from c. when it is recycled d. never ️when is it used in the equipment is was removed from any person who performs maintenance, service or repair that could reasonably be expected to release class 1 or class 11 refrigerants to the atmosphere would be considered what a. maintenance personnel b. technician c. business owner d. contractor ️technician the unthreaded portion of piping outlets shall extend not less than ___ above floors? a. 1" b. 6" c. 12" d. none of the above ️none of the above ducts must not be installed less than how far above the earth a. 6" b. 12" c. 4" d. 2" ️4" any appliance with an ignition source and located in a hazardous location such as garages, the ignition source must be how far above the floor? a. 24" b. 12" c. 18" d. 8" ️18" the static pressure exerted in a drum of R-410A at 75 degrees F is most nearly a. 217 psig b. 125 psig c. 132 psig d. 312 psig ️217 psig on a R-22 cooling unit, the suction pressure is 32.8 psig and the leaving evaporator temperature is 30 degrees. what is the system superheat? a. 3 degrees b. 12 degrees c. 40 degrees d. 20 degrees ️20 degrees when performing a nitrogen pressure test on a refrigerant piping system in a unit over 20 tons, how long should the test remain on? a. 6 hours b. 12 hours c. 1 hour d. 24 hours ️24 hours in general soldering alloys melt under what temperature a. 1250 degrees f b. 112 degrees f c. 800 degrees f d. 500 degrees f ️800 degrees f in section 440-x-3-09 in the statute the certified contractor holding a certification with the board of heating, air conditioning and refrigeration contractors is deemed "responsible in charge" would hold what position in the company? a. corporate officer or partner b. regularly employed person c. member of the llc d. any of the above ️any of the above according to the environmental protection agency releasing refrigerants int the atmosphere can cause damage to the earth's what a. stratosphere b. foundation c. ozone d. sky ️ozone appliances in compartments shall be accessed by an opening or door and unobstructed passageway not less than ___ wide a. 24" b. 36" c. 12" d. 48" ️24" the boiling temperature of refrigerants rise as: a. the latent heat drops b. the pressure is decreased c. the pressure is increased d. the wet bulb is reduced ️the pressure is increased refer to house 1 drawing and calculate the net heat gain on the north wall. the net heat gain is most