Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
10 Cards in this Set
- Front
- Back
|
When the outdoor air damper increases the flow of fresh air, which of the following is true?
a) The return air damper throttles up to reduce the volume of recirculated air. b) The return air damper throttles up to increase the volume of returned air. c) The return air damper is not affected. d) The return air damper throttles down to reduce the volume of returned air. e) The return air damper throttles up to increase the volume of returned air. |
D
|
|
|
To provide a two position damper, equipped with a fan that provides 100% outdoor air, with a ratio of damper opening what is required? a) A gradual switch b) Offset returned air duct c) An air mixer d) A three phase damper interchange e) A variable volume tank |
A
|
|
|
In severely cold weather what adjustment must be made to properly preheat the outside air? a) The temperature controller's throttling range must be increased b) The outdoor damper should be closed c) Two separate preheater coils should be installed d) Damper must be heated e) Preheat coil temperature should be increased |
C
|
|
|
Which of the following is not a correct method of heat regulation? a) Direct modulation of the control valve on the steam or hot water to the heating coil b) Modulating the position of a 3-way mixing valve on the hot/cold water line into the coil c) Modulating the relative positions of face and bypass dampers controlling air flow across the coils d) Modulating the actuators or the steam or water supply in conjunction with the coil bypass damper e) Modulating the valve and the face and the bypass damper 30 degrees out of phase. |
E
|
|
|
Air conditioning with respect to heating coils is achieved in which of the following ways? a) A combination of tempering control functions b) The selected mixing of warm return air and cooler outside air c) Selective heating by passing air through the heating coils d) Proportioning the amount of air flow through the face damper for heat addition, or through the bypass dampers for no heat addition. e) All of the above |
E
|
|
|
A main advantage of steam type humidifiers over pan type humidifiers is that a) steam type humidifiers are inexpensive b) there is minimal time lag with steam type humidifiers c) steam types can achieve higher relative humidity d) steam types do not require a humidistat e) steam type humidifiers require less space |
B
|
|
|
Dehumidification is achieved by a) absorbing the moisture with a sponge filter b) absorbing moisture with a chemical drying agent c) cooling the air to a corresponding dew point temperature d) heating air to a corresponding wet bulb temperature e) saturating the air until the precipitation point at room temperature is reached |
C
|
|
|
To prevent too frequent starting and stopping of the compressor in a cooling system what should be done? a) Regulate the operation of the compressor with a set point thermostat b) Turn off the compressor when temperatures required for conditioning are reached c) Run the compressor continuously and vent any excess cold air d) Run the main fan only e) Run the compressor continuously and modulate refrigerant flow |
E
|
|
|
To control static pressure in the air ducts a differential pressure controller is installed. How does the controller control static pressure? a) By increasing air temperature b) By decreasing air temperature c) By modulating the damper on the suction side of the fan d) By modulating the damper on the discharge side of the fan e) By grounding the ductwork and carrying the charge to a battery |
C
|
|
|
When complete control systems become very complex, which control signal medium is preferred? a) Pneumatic b) Electric c) Electronic d) Digital e) Fibre optic |
A
|
