Installation Flashcards
Identify the air distribution system used in modern residential buildings in which the air pressure remains steady from one end of the system to the other
Reducing plenum system
When installing galvanized rectangle duct 8” x 20” the metal should be at least
28 gage
When the proper size duct materials are used the occupants of the home should
Not feel air movement
Should not hear air noise
Should not feel temperature swing
When conditioned air travels through an unconditioned space such as an attic or crawl space the duct must be insulated if the air temperature difference is
15 degrees f
Air Conditioning/Refrigeration (ACR) tubing is measured by its
Outside dimension
On air conditioning systems the __________ tubing is often insulated to reduce heat transfer to the refrigerant.
Low pressure line
Most air conditioning tubing is brazed using _________ as a filler material
15% silver
__________ draws the filler alloy into space between the base metals when brazing
Capillary action
A vacuum pump is used to reduce a systems pressure to
500 microns
On larger systems it is more practical to add refrigerant in the liquid phase, however the technician must make certain no _________ enters the compressor
Liquid
What is the superheat of an R-22 air conditioning system if the evaporator boiling point temperature is 40 degrees f and the suction line temperature is 52 degrees f?
12 degrees
When installing a central air conditioning system the entire refrigerant charge is typically
Shipped and held in the condensing unit
Vacuum pump oil must be changed on a regular basis because it can become very contaminated with
Moisture
To calibrate a gauge manifold a technician should
Open the gauge to the atmosphere, it should
