Indoor Pool Heater Sizing Calculator

Indoor Pool Heater Sizing Formula:

\[ BTU/h = \frac{Pool\ Volume\ (gal) \times Temp\ Rise\ (°F) \times 8.33}{Time\ (h) \times \eta} \]

Pool Volume:

gal

Temperature Rise:

°F

Heating Time:

Heater Efficiency (η):

decimal

Required Heater Capacity:

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1. What is Indoor Pool Heater Sizing?

Indoor pool heater sizing calculates the required BTU capacity to heat a swimming pool to the desired temperature within a specified time frame, accounting for heater efficiency and pool volume.

2. How Does the Calculator Work?

The calculator uses the pool heater sizing formula:

\[ BTU/h = \frac{Pool\ Volume\ (gal) \times Temp\ Rise\ (°F) \times 8.33}{Time\ (h) \times \eta} \]

Where:

\( Pool\ Volume \) — Total water volume in gallons
\( Temp\ Rise \) — Desired temperature increase in °F
\( 8.33 \) — Weight of one gallon of water in pounds
\( Time \) — Desired heating time in hours
\( \eta \) — Heater efficiency (typically 0.80-0.95)

Explanation: The formula calculates the energy required to heat the pool water and divides by time and efficiency to determine the required heater output.

3. Importance of Proper Heater Sizing

Details: Correct heater sizing ensures efficient operation, prevents energy waste, maintains comfortable water temperature, and extends equipment lifespan. Undersized heaters struggle to maintain temperature, while oversized units cycle frequently and waste energy.

4. Using the Calculator

Tips: Enter pool volume in gallons, desired temperature rise in °F, available heating time in hours, and heater efficiency as a decimal (e.g., 0.85 for 85% efficiency). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical heater efficiency for indoor pools?
A: Most modern pool heaters have efficiencies between 80-95%. High-efficiency models can reach 95%, while standard models are typically 80-85%.

Q2: How do I calculate my pool volume?
A: For rectangular pools: Length × Width × Average Depth × 7.48. For circular pools: π × Radius² × Average Depth × 7.48.

Q3: What temperature rise is typical for indoor pools?
A: Most indoor pools are maintained at 78-82°F. Temperature rise depends on initial water temperature and desired swimming temperature.

Q4: How long should it take to heat a pool?
A: Typically 24-48 hours for initial heating, but this depends on pool size, heater capacity, and temperature difference.

Q5: Does this account for heat loss?
A: This calculation provides the BTU requirement for heating the water only. Additional capacity may be needed to compensate for heat loss through evaporation and conduction.