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.
What is a counterflow style furnace?
A counterflow furnace is the one which simply has the plenum on the bottoml allowing for proper under slab heating.
His do we connect piiping?
With spiral connectors.
In what direction should piping in underslab Heating slope?
Always towards the furnace.
What is one unique feature of a slab endcap?
It has wings which just down inside the pipe the which prevent it from collapsing.
What kind of piping must be used with high efficiency appliances?
ULC S636 PVC must be used for BH Type venting.
What do all non electric furnaces and hot water Tanks need?
Combustion air. Brought in through an intake hood installed on the outside of the house.
How did we dispose if fumes from furnaces etc. ?
Through a common vent on the outside of the house. It goes: flu collar connection (on appliance)–>vent connector( really just more or less pipe) —> hood of vent.
What is a vent connector?
It’s a portion of the combustion venting system that conveys the flue gases from the appliance to Common vent or chimney. Often made of single wall pipe; heavy gauge depending on heat pipe is exposed to.
What is a B vent connector?
Double walled vent connector used on gas appliances. Keeps gases warm to make them exit the building. Also used in close proximity to combustibles. Withstands up to 243°C
What’s a ventilated thimble?
An accordion-like arrangement which goes over pipe and allows it to escape harmlessly midst a combustible wall. If wall is combustible this MUST be used.
If you see an empty masonry chimney, you…?
Line it! With an aluminum chimney liner.
What is a draft hood connector?
Also called a double to single wall connector. Kind of self explanatory.
What is L-Vent?
Similar to be efficient but withstands higher temperatures. Often used with oil fired appliances.
How should intake could be connected?
With foil backed flex.
What is Exfiltration?
The uncontrolled leakage of air from a building.
What is combustion air?
Combustion air is Air taken into the house. Specifically to the furnace room to allow all the appliances to function properly.
What is a air combustion terminal, and what is it also called?
Also called Eskimo trap. This device regulates the air which spills into the furnace room from the combustion air intake. It prevents excessive amounts of air spilling into the room when the machines are not running.
What is in HRV? Can it be used solely as a residence’s ventilation fan?
Heat recovery ventilator!
Yes!
What is a Backdraft damper?
A little flap inside a ventilation hood which prevents the Backdraft or cold air from getting into the house.
Which is more efficient? Foilback solid pipe or insulated flexible duct
Foil back solid
Where on the furnace is fresh air normally brought to?
The return side of the furnace. Duh!
What is the maximum slope amount when venting a furnace?
1/4” per foot
Is it possible and permissible to vent a furnace vertically through the roof?
Yes to both.
What’s the difference between full and half throat.
Half throat is uh… Half the size of the opening. Full throat is just as much of more.
The air is ________ from the heating or cooling unit by the supply air system.
Distributed
What is the heart of the heating ventilation and air conditioning system?
The air recirculation fan.
Dynamic losses on flexible duct are approximately _____ times as great per foot On smooth duct.
.
