829 Copyright Goodheart-Willcox Co., Inc. 10 7. The purpose of blank-off plates is to _____. A. block the evaporator so air does not pass through when the furnace is operating B. block off areas of the plenum so all the air passes through the evaporator C. prevent airflow-related noises in the ductwork D. provide access to the evaporator for service 8. Which of the following statements regarding refrigerant lines is not true? A. A liquid line should be insulated to prevent condensation. B. Refrigerant lines may be connected with flare connections. C. Refrigerant lines should be kept as short as possible. D. All of the above. 9. The electrical connections to a central air- conditioning condensing unit typically include a 240 V connection for powering the compressor and a _____ connection for control. A. 24 V B. 36 V C. 100 V D. 480 V 10. Scheduled periodic maintenance does not involve inspecting _____. A. the thermostat B. duct registers C. the air handler D. All of the above should be inspected during scheduled periodic maintenance. 11. When installing a ductless split system indoor unit, a _____ is typically necessary. A. 3″ (8 cm) hole wall opening B. 42″ × 16″ wall opening C. gas supply drip leg D. typical window opening 12. Which of the following statements is true of ductless split systems? A. The system can have multiple indoor units attached to a single outdoor unit. B. The system can have multiple outdoor units. C. They are a popular choice for adding air conditioning to buildings that are not equipped with ducts. D. All of the above. 13. Which of the following statements regarding ductless split systems is not true? A. A single, central thermostat controls the temperature in all conditioned spaces. B. A line set connects an indoor unit and outdoor unit. C. A variety of different indoor unit styles is available. D. All of the above. 14. What should be added to a ductless split system’s indoor unit to prevent the growth of microorganisms? A. Biocide tablets. B. A condensate pump. C. High-temperature cutoff switch. D. An overflow switch. 15. Which device is used to prevent spilling of condensate from a ductless split system’s indoor unit? A. Air filter. B. Biocide tablets. C. Mounting bracket. D. Overflow switch. Critical Thinking 1. List everything that a well-equipped central air- conditioning system is capable of doing to air. 2. List the four major steps for installing split central air-conditioning systems. 3. What may happen if excessive pressure is applied to a wrench when tightening a quick-connect fitting? 4. List some building and local area changes that might require using a replacement air-conditioning system with a different capacity from the original. 5. Explain some of the things that may happen if a suction line is not insulated. 6. Describe the different ways and locations an outdoor unit for a ductless split system may be installed.