Residential HVAC components Flashcards
Special fresh air ventilation fittings must be used to connect the fresh air duct to the return trunk duct
False
The combustion air termination is used to ?
Keep cold air from dropping into the furnace room.
Both factory built chimneys and vents have a system of parts that are _____________ by a recognized testing agency.
Certified.
Installations requiring you to run forced air heating under the concrete slab are known as:
Underslab heating.
Roofjacks used on dryer vents are available without which of the following?
Birdscreen
What is used to connect the return air branch runs to the main duct called?
Joist Liner, joist ends, and sometimes can be hard piped (snap lock).
The material used for venting of the fan to the outside must be metal duct with insulation and vapour barrier, such as foilback insulation.
False
Furnaces require air to fuel the fire inside of them. This is called _____________ air.
Combustion.
The entire underslab ducting system must slope _________ the furnace.
Back to.
When a return air branch run is finished on the bottom with a drywall ceiling, the bottom of the branch run is finished with:
Thermopan
______________ is the uncontrolled leakage of air from the building.
Exfiltration.
What does a type L-vent construction consist of?
An outer casting of Galvalume/ airspace / inner liner of stainless steel.
The ductwork coming off the plenum for underground heating installations will be ____________ for strength and to make it easier to seal against moisture in the ground.
Round.
A 14”x8” return air grille:
Covers a 14”x8” hole
What is the heart of the heating, ventilation and air-conditioning (HVAC) system?
The air recirculation fan
The air is _____________ from the central heating or cooling unit by the supply air system.
Distributed
The return air part of an HVAC system consists of the parts to bring air back from the ______________ to the furnace
occupied space
Rectangular duct takeoffs include:
Top take-offs, Side take-offs, saddle take-offs
The ration between the width and depth of the duct should never exceed:
4:1
Name 4 things that can cause dynamic loss in an air stream
Material duct is constructed, changes in direction, shape of the duct, changes in cross sectional area.
Dynamic losses on flexible duct are approximately ____ times as great per foot as in smooth duct
10 times
Dynamic losses occur in both rectangular and round duct
true
You should always install two elbows together (back to back)
False
