Dear All,

I am comparing the energy performance of a constant volume and variable volume
system for a composite climate of India (New Delhi) in EnergyPlus. The building
area is 7500 sq m. The chiller capacity is same for both the cases. The chilled
water to the cooling coils is supplied by a constant speed pump.

The savings in the fan energy is evident due to variable speed of the supply fan
in case of VAV. However i am getting energy saving in cooling energy (chiller
energy) also, in VAV compared to CAV, which i feel is due to higher delta T
(chilled water) across cooling coil for CAV compared to VAV, this in turns
increases the chiller electricity consumption. However while discussions with
some consultant, it is their feeling that the cooling energy would remain same
for both type of systems.

I want to ask has someone else tried this simulation and would there be any
difference in cooling energy or not?

Thanks in advance.
Deepak