Question

this heat and air conditiong question, PLEASE i need solution and reasons. due date is 6 june.

4. Specify if the following statements are true (1) or false (x)? a) Dual duct systems are constant air volume systems b) Dual duct systems can provide simultaneous cooling and heating c) Dual duct systems are energy efficient d) Dual duct systems occupy more space compared to single duct systems

Answer 1

Ans. a) True

Dual duct systems are constant air volume system which uses cooling and heating coils that are placed separate in ducts. There is a single fan to supply constant Volume air to ducts which is then distributed throughout the system to meet the conditioning requirements.

b) True

In this two supply ducts run to each space for conditioning , one for cold air and another for warm air each individually controls the space . Air from these two ducts is mixed in a mixing box and then supplied to space . So cooling and heating can be achieved simultaneously.

c) False

Dual ducts has high energy consumption due to mixing of streams and it has two fan duct each fan size to handle almost half of total system air flow i.e 50%

d) True

Dual ducts occupy more space for running of two ducts these have to be sized to handle entire air flow rate.it also require a lagla number of mixing boxes to maintain conditioning so these setup increases space requirement through the area to be conditioned.