Quiz
Unit 37 - Quiz
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Perguntas do quiz (20)
1The pressure in a duct system is measured in:
- Apsig
- Bpsia
- C" Hg
- D" WC
2The __________ or fan provides the pressure difference to force the air into the duct system, through the heat transfer surfaces in the conditioning equipment, through the grilles and registers, and into the room.
- Ablower
- Bforcer
- Ccompressor
- Dcondenser
3The atmosphere exerts a pressure of __________ at standard atmospheric conditions.
- A12.696 psi
- B14.696 psi
- C16.696 psi
- D18.696 psi
4Measuring velocity pressure in a duct indicates the __________.
- Avolume of air through a duct
- Bspeed at which the air is moving
- Cpressure against the sides of the duct
- Dweight of the air moving through the duct
5An air pressure measuring instrument __________
- Awater velometer
- Bwater manometer
- Cair manometer
- Dair velometer
6Why we use a reducing plenum system is to __________.
- Asave materials
- Bkeep the noise level low
- Ckeep the duct pressures constant
- Dboth a and c
7A(n) _________ degree F temperature difference from inside the duct to outside the duct is considered the maximum difference allowed before insulation is necessary.
- A15
- B18
- C20
- D22
8If the equivalent length of a transition piece of ductwork is 10 feet and the main duct in series with it is 20 feet, what is the length used to estimate the total frictional loss?
- A10 feet
- B30 feet
- C60 feet
- D20 feet
9What is an air conditioning systems capacity in tons if the supply air is moving through a 12" x 24" main duct at a velocity of 400 feet per minute.
- A1 ton
- B3 tons
- C2 tons
- D2.5 tons
10If you were to use a vane anemometer to check air flow what velocity pressure would you use if your traverse readings were: 475, 500, 500, 450, 500, 525, 550, 500, 450, 500, 525, 475
- A500 ft./min.
- B513 ft./min.
- C500" w.c.
- D487 ft./min.
11One psi is equivalent to:
- AAtmospheric pressure
- B34 ft. w.c.
- C27.7" w.c.
- D14.7" w.c.
12The main reason for using a reducing extended plenum system is to __________.
- Asave metal by using a smaller duct
- Breduce the operating cost of the system
- Cprovide easier means of fastening the take off fittings
- Dmaintain a more even pressure throughout the entire length of the trunk duct
13The forced-air system is different from a natural-draft system.
- AVerdadeiro
- BFalso
14The duct pressure equals the velocity pressure plus static pressure.
- AVerdadeiro
- BFalso
15Adjusting the tension on the belt will alter the rate at which air is moving through the system, but does not affect the amperage draw of the motor.
- AVerdadeiro
- BFalso
16Canvas collars are generally made of canvas rather than other materials such as rubber.
- AVerdadeiro
- BFalso
17Oversized duct systems cost more to fabricate and install and will also result in the slowing of the air as it flows through the duct.
- AVerdadeiro
- BFalso
18The device used to put trunk duct or extended plenum sections together is called a drive clip.
- AVerdadeiro
- BFalso
19Friction due to air rubbing the walls of the ductwork can be eliminated.
- AVerdadeiro
- BFalso
20The main drawback of the extended plenum system is that the velocity of the air is lower as the air reaches the last takeoffs on the extended plenum.
- AVerdadeiro
- BFalso
Informações
- Descrição
- Unit 37 Air Distribution and Balance
- Autor
- Neil Revollo
- Idioma
- English
- Visualizações
- 3.080
- Avaliação
- 5,0 de 5 · 1 avaliação Avalie este quiz