How To Calculate Chilled Water Flow Rate

Chilled Water Flow Rate Equation:

\[ Flow = \frac{Q}{\rho \cdot c_p \cdot \Delta T} \]

Heat Transfer Rate (Q):

Density (ρ):

kg/m³

Specific Heat Capacity (cₚ):

J/kg·K

Temperature Difference (ΔT):

Chilled Water Flow Rate:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Chilled Water Flow Rate?

The chilled water flow rate represents the mass flow rate of chilled water required to achieve a specific heat transfer in HVAC systems. It is a critical parameter in designing and operating chilled water systems for air conditioning and industrial cooling applications.

2. How Does the Calculator Work?

The calculator uses the fundamental heat transfer equation:

\[ Flow = \frac{Q}{\rho \cdot c_p \cdot \Delta T} \]

Where:

\( Flow \) — Chilled water mass flow rate (kg/s)
\( Q \) — Heat transfer rate (W)
\( \rho \) — Density of water (kg/m³)
\( c_p \) — Specific heat capacity of water (J/kg·K)
\( \Delta T \) — Temperature difference across the system (K)

Explanation: This equation calculates the mass flow rate required to remove a specific amount of heat given the water's thermal properties and the desired temperature change.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is essential for proper system sizing, pump selection, energy efficiency optimization, and ensuring adequate cooling capacity in HVAC systems.

4. Using the Calculator

Tips: Enter heat transfer rate in watts, water density in kg/m³ (typically 1000 for water), specific heat capacity in J/kg·K (typically 4186 for water), and temperature difference in Kelvin. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for water density and specific heat?
A: For water at standard conditions: density ≈ 1000 kg/m³, specific heat capacity ≈ 4186 J/kg·K.

Q2: How does temperature affect the calculation?
A: Higher temperature differences require lower flow rates for the same heat transfer, making the system more efficient.

Q3: What is a typical ΔT for chilled water systems?
A: Typical ΔT values range from 5-12°C (5-12K) depending on system design and application requirements.

Q4: Can this formula be used for other fluids?
A: Yes, but you must use the correct density and specific heat capacity values for the specific fluid being used.

Q5: How do I convert mass flow rate to volumetric flow rate?
A: Volumetric flow rate = Mass flow rate / Density (m³/s = kg/s ÷ kg/m³).