110104f - Residential HVAC components Flashcards
What is a short way elbow?
When the cheek is short. ;)
What is a PTO?
Plenum take off
What is a log way elbow?
Where the cheek is long. :P
What’s the maximum ratio for duct?
4:1 so, If one side was 6 the other side could be no more than four times bigger.
Where should the volume damper be located?
Nearest the trunk line, OR close to the diffuser.
What about pipe supports?
These should be places near every joint and elbow. Must be metal either steel or angles with flattened ends.
How much airflow pressure is lost with one elbow?
Ten feet worth.
What does a centerline change symbol look like?
A c with a diagonal line through it.
How many kinds of boots are there?
End boot
universal boot
right angle boot
Kickboot
What is stacked duct and what is it used for?
To get through a point where all round duct won’t do: such as a wall. The assembly would be: round, boot, stack duct, boot, round again
What does the basement termination boot look like?
An ordinary right angle boot with wings to attach to joists.
What are two ways to terminate a branch run in a basement?
Under slab piping using stacked duct or a basement termination boot.
What’s a frost wall?
And insulated wall built on the inside of the concrete basement wall which allows termination closer to the floor. :-)
How many types of takeoffs are there and what are they?
There aTop takeoff side take off Universal take Off saddle takeoff two-way top take off
What is joist liner?
Joist liner is what is used to seal any holes in a joist. For example the bottom of the joist assuming a drop
ceiling was used.
Materials can include:
Light gauge metal
Thermopan,
Plastic or drywall.
What’s a return air shoe?
It’s an Elbow that changes size from the drop talked to the filter rack. There should be turning veins in this elbow. Also, there should be a filter rack closest to the furnace.
Which does under slab heating use? Round or square duct?
It is intended to use round duct.
What is a slab stake and how was is it used?
A slab steak is a piece of heavy gauge galvanized angle which is wired to the under slab pipe. It keeps the pipe where it needs to be.