In constant-primary chilled water distribution, for the same load (Btu/h or kW) if the design ΔT across the cooling coil is increased, the required flow (gpm) must:
Choices
- (A) Increase linearly with ΔT
- (B) Decrease (Q = ṁ c_p ΔT, so ṁ ∝ 1/ΔT for same Q and cp)
- (C) Stay the same (always 2.4 gpm/ton by law)
- (D) Depend only on chiller LWT
Correct answer: (B)
Decrease (Q = ṁ c_p ΔT, so ṁ ∝ 1/ΔT for same Q and cp)
Explanation
Coil/loop flow ∝ 1/ΔT at same load — energy efficiency and pump trade-offs.