Author Question: PTAC and window-unit air conditioners often use rotary compressors, which are effective but ... (Read 111 times)

genevieve1028 · **on:** Jul 24, 2018

PTAC and window-unit air conditioners often use rotary compressors, which are effective but susceptible to failure due to high head pressure. What is the most common cause of high head pressure in these units?

A) Dirty condenser B) Metering device failure
C) Incorrect charge D) Dirty evaporator

Question 2

The space above the drop-in ceiling in a commercial building is often used:

A) As a return air plenum.
B) To help clean the air by allowing airborne particles to settle in the ceiling.
C) As an open wire trough for the building's wiring.
D) As a supply air distribution system.