In a variable-primary-flow chilled water plant (no decoupler bypassing full flow in idea), a VFD on the chiller pump is primarily modulated to maintain what, subject to chiller mfr limits?

Choices

• (A) Refrigerant GWP 0 by law
• (B) Duct FPM at grille only
• (C) Domestic 60 psi at faucet
• (D) Required ΔT and/or minimum/bounded flow and acceptable lift through chiller, per mfr+controls