A factory has two zones. Zone 1 and 2 are both maintained at 75FDB. The design supply air flow rates to Zone 1 and 2 are 320 and 200 CFM, respectively. At a certain hour in summer, the cooling loads for Zone 1 and 2 are 6,000 Btu/hr and 3,000 Btu/hr, respectively.
Assume dry air conditions and air density of 0.075 lbm/ft3 .
(a) If a dual-duct constant-volume system is used with discriminator control for both cold and hot air, what would the required amount of reheat (Btu/hr) be provided by the hot air in each zone at the hour? The design cold and hot air supply temperatures are 55FDB and 100FDB, respectively.
(b) If a VAV system with 20% minimum position is used with discriminator control, what would the required amount of reheat (Btu/hr) be provided by a reheater in each zone at the hour? The design supply air temperature is 55FDB
The Attempt at a Solution
I just want to know what discriminator control is in the context of this problem. I cant find any example problems like these on Google.