HVAC S.T.A.R QUESTIONS AND ANSWERS ALREADY PASSED

HVAC S.T.A.R QUESTIONS AND ANSWERS ALREADY PASSED The evaporator in a refrigeration system: Is the component where refrigerant boils and absorbs heat. The purpose of the compressor is to change ___________. Low-pressure, low-temperature vapor to a high-pressure, high temperature vapor A common refrigerant leak detection device is the: Halide torch. Copper-plating of compressor parts is: Caused by contaminants in the system. If not properly installed, a hot-gas muffler might trap: Oil. Unit ventilators are usually equipped with outside air dampers to: A. Partial Correct: Provide ventilation air during building occupancy B. Partial Correct: Comply with most local or state codes Face and bypass dampers should be adjusted to provide: Tight shut off to reduce the possibility of overcooling or overheating With belt driven equipment, alignment of the motor and driven equipment pulleys Is accomplished using a string or straight edge. To assist consumers in making an informed choice when purchasing unitary air conditioning equipment, the efficiency of such units is expressed as Energy Efficiency Ratio (EER or SEER) the units of which are: Btuh/watt Firestats located in the air stream of air handling units: A. Partially Correct: Are required in both the supply and return air streams B. Partially Correct: Should be the manual reset type C. Partially Correct: Should be nonadjustable A sleeve bearing would typically be used in a motor that: Operates with a light load and where noise is a factor. A bearing used on the bottom of a motor where the shaft is positioned vertically is called a ____________ bearing. Thrust To produce electromagnetism, relative motion is required between a magnetic field and a/an: Conductor Materials which do not allow their electrons to spin out of orbit easily are called: Insulators A battery is an example of a/an ____________ source. Direct current "Current flowing through a conductor in one direction for a split second, then in the opposite direction for a split second" would be a good definition of: Alternating current If a pressure gauge reads five psig at sea level elevation, the corresponding absolute pressure is ___________ psia. Fractional The portion of the electromagnetic spectrum to which solar collectors respond is _____ and near- infrared radiation. Visible light During winter, ________. Daylight is shorter and the Northern Hemisphere is angled away from the sun Unless equipped with OSHA or Canadian Standards Association (CSA) approved ground-fault circuit interrupters, portable electric lighting used in wet and-or other conductive locations as, for example, drums, tanks and vessels, shall be operated at ______ volts or less. 12 Receivers are usually required in systems having: