A water-source heat pump does not require a defrost cycle because:
A) There are no check valves or extra metering devices within a water-source heat pump.
B) It uses buried loops in which water is circulated, and the heat is then extracted from the water.
C) The fluid circulating through the water-source unit cannot be allowed to freeze.
D) Most water-source units use a single bi-flow thermostatic expansion valve.
[Ques. 2] When checking combustion efficiency, which measurement should be taken first?
A) Draft B) Smoke C) Stack temperature D) Oxygen
[Ques. 3] Which of the following overcurrent protection devices would be appropriate for an air-conditioning condensing unit whose rating plate says MAX FUSE or HACR CIRCUIT BREAKER 35 AMPS?
A) A 35 A HCAR circuit breaker
B) A 35 A circuit breaker
C) A 30 A time delay fuse
D) No fuse or circuit breaker is necessary; but if one is used, it cannot exceed 35 A.
[Ques. 4] Why is the cooling temperature difference often different from the difference between the indoor and outdoor temperatures?
A) The cooling temperature difference takes heat storage and daily temperature range into account.
B) ACCA weather data is more accurate than the National Weather Bureau.
C) The cooling temperature difference takes latent heat gain into account.
D) Air-conditioning equipment manufacturers use their own temperature scale established by AHRI, which is different from either Fahrenheit or Celsius.
[Ques. 5] The most important elements to check for in gas furnaces are adequate combustion air and:
A) Electrical connections. B) Refrigerant levels.
C) Proper venting. D) Airflow components.