Intro to hvac questions and answers already passed

Intro to hvac questions and answers already passed Which of these heating methods is most commonly used as a heat source in cold climates? Natural gas furnaces Which of the following is a device used to maintain indoor air quality? Ultraviolet light The purpose of an evaporator in a refrigeration cycle is to transfer heat from the air to the refrigerant Heat can be transferred from a refrigerant to the outdoors on a hot day because the refrigerant is warmer than the out door air The expansion valve in the mechanical refrigeration system provides pressure drop Oxygen is never used to purge an Hvac system because an explosion could occur under a certain conditions Which of these devices is used for energy conservation? Heat recovery ventilator In order to reduce duct leakage, ducts should be sealed with mastic If a refrigerant is removed from a system and held in a storage tank for return to the same system, it is said to have been recovered Local building codes are based on the International Building Code Refusing to cut corners on a job is a example of honesty Speaking well of your employer to others is an example of loyalty How many hours each year does a typical apprenticeship trainee spend in the OJL? 2,000 A company that would respond to a service request for a chiller would most likely be a mechanical contractor An employee who works as a test technician