1. What is a Cooling Tower Sizing Calculator?

Definition: This calculator determines the total heat rejection required for proper cooling tower sizing based on water flow rate, temperature difference, and latent heat.

Purpose: It helps HVAC engineers and facility managers properly size cooling towers for industrial and commercial applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total heat rejection (BTU)
• \( m \) — Water flow rate (lb)
• \( c \) — Specific heat of water (BTU/lb·°F)
• \( \Delta T \) — Temperature difference (°F)
• \( Q_{latent} \) — Latent heat from evaporation (BTU)

Explanation: The calculator sums the sensible heat (from temperature change) and latent heat (from evaporation) to determine total cooling requirements.

3. Importance of Proper Cooling Tower Sizing

Details: Correct sizing ensures efficient heat rejection, prevents equipment overload, and maintains optimal system performance while minimizing energy costs.

4. Using the Calculator

Tips: Enter water flow rate in pounds, specific heat (1.0 BTU/lb·°F for water), temperature difference, and any latent heat from evaporation. All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical specific heat value for water?
A: Pure water has a specific heat of 1.0 BTU/lb·°F, but this may vary slightly with impurities or additives.

Q2: How do I determine the latent heat value?
A: Latent heat depends on evaporation rate. For precise calculations, measure evaporated water and multiply by 970 BTU/lb (heat of vaporization).

Q3: What temperature difference should I use?
A: Use the difference between entering and leaving water temperatures (typically 10-30°F for cooling towers).

Q4: How do I convert GPM to lb for water flow rate?
A: Multiply GPM by 500 (1 GPM ≈ 500 lb/hr at standard conditions).

Q5: Should I add a safety factor to the results?
A: Yes, most applications add 10-20% to the calculated heat rejection for design safety margins.