Question 216General Subjects - 1st Asst/Chief70% to pass
Referring to the illustrated dual duct multiple zone HVAC system, how is the space temperature directly controlled? Illustration GS-RA-43
AI Explanation
A) The space air temperature is controlled by automatically proportioning the cold and hot air streams at the mixing unit.
This is the correct answer. In a dual duct multiple zone HVAC system, the space air temperature is controlled by automatically mixing the cold and hot air streams at the mixing unit. The system senses the space temperature and adjusts the proportions of cold and hot air to maintain the desired temperature in the conditioned space.
The other options are incorrect because they do not accurately describe how the space temperature is directly controlled in this type of HVAC system. Options B, C, and D involve controlling the temperature through the preheat, cooling, or reheat coils, respectively, rather than the direct mixing of the air streams.
Related Questions
#214 With regard to the cooling and heating coils and humidification and regeneration chambers of a liquid cargo-hold dehumidification system, what statement is true? #215 In the illustrated terminal reheat multiple zone system, what statement represents the functioning of the summer outside air duct thermostat? Illustration GS-RA-42 #217 Referring to the illustrated single zone HVAC system diagram, what statement is true concerning the damper controls? Illustration GS-RA-09#219 In the illustrated single zone HVAC system, what prevents the simultaneous flow of steam through the preheat coil and flow of chilled water through the cooling coil? Illustration GS-RA-09 #220 Referring to the illustrated psychrometric chart, under what conditions are the dry bulb, wet bulb, and dew point temperatures for air all equal in value? Illustration GS-RA-22