Swimming Pool Evaporation Rate Calculator
.calculator-container {
font-family: Arial, sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 600px;
margin: 20px auto;
background-color: #f9f9f9;
}
.calculator-title {
text-align: center;
color: #333;
margin-bottom: 20px;
}
.calculator-inputs {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
gap: 15px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.input-group input {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1em;
}
.calculator-button {
grid-column: 1 / -1;
padding: 12px 20px;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 1.1em;
margin-top: 10px;
transition: background-color 0.3s ease;
}
.calculator-button:hover {
background-color: #45a049;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
background-color: #e7f3fe;
border: 1px solid #b3d7fc;
border-radius: 4px;
font-size: 1.1em;
color: #333;
text-align: center;
}
.calculator-result strong {
color: #007bff;
}
function calculateEvaporation() {
var poolSurfaceArea = parseFloat(document.getElementById("poolSurfaceArea").value);
var averageWindSpeed = parseFloat(document.getElementById("averageWindSpeed").value);
var averageAirTemperature = parseFloat(document.getElementById("averageAirTemperature").value);
var averageWaterTemperature = parseFloat(document.getElementById("averageWaterTemperature").value);
var averageRelativeHumidity = parseFloat(document.getElementById("averageRelativeHumidity").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (isNaN(poolSurfaceArea) || isNaN(averageWindSpeed) || isNaN(averageAirTemperature) || isNaN(averageWaterTemperature) || isNaN(averageRelativeHumidity)) {
resultDiv.innerHTML = "
Error: Please enter valid numbers for all fields.";
return;
}
if (poolSurfaceArea <= 0 || averageWindSpeed < 0 || averageAirTemperature 120 || averageWaterTemperature 100 || averageRelativeHumidity 100) {
resultDiv.innerHTML = "
Error: Please enter realistic values for all fields.";
return;
}
// Simplified evaporation calculation based on common factors.
// This is an approximation. More complex models exist.
// Factors considered: surface area, wind speed, temperature difference, humidity.
// Base evaporation rate (gallons per day per square foot) – this is a typical reference value
var baseEvaporationRate = 0.25; // Example base rate, can vary
// Wind speed factor: Higher wind increases evaporation.
var windFactor = 1 + (averageWindSpeed * 0.02); // Adjust multiplier as needed
// Temperature difference factor: Higher water temp vs air temp increases evaporation.
// Using a simplified approach; a more accurate method would involve vapor pressure.
var tempDifference = averageWaterTemperature – averageAirTemperature;
var tempFactor = 1 + (tempDifference * 0.01); // Adjust multiplier as needed
// Humidity factor: Lower humidity increases evaporation.
var humidityFactor = 1 + ((100 – averageRelativeHumidity) * 0.01); // Adjust multiplier as needed
// Combine factors
var calculatedEvaporationRateSqFt = baseEvaporationRate * windFactor * tempFactor * humidityFactor;
// Total daily evaporation in gallons
var totalDailyEvaporation = calculatedEvaporationRateSqFt * poolSurfaceArea;
// Convert to inches per day for a more common metric
// 1 cubic foot = 7.48 gallons
// 1 foot = 12 inches
// Gallons per sq ft per day * (1 cu ft / 7.48 gal) * (12 in / 1 ft) = Inches per sq ft per day
var evaporationInchesPerDay = (calculatedEvaporationRateSqFt / 7.48) * 12;
var totalDailyEvaporationInInches = evaporationInchesPerDay * poolSurfaceArea;
resultDiv.innerHTML = "Estimated daily pool evaporation:
" + totalDailyEvaporation.toFixed(2) + " gallonsor approximately
" + totalDailyEvaporationInInches.toFixed(3) + " inches from the pool surface.";
}
Understanding Swimming Pool Evaporation
Swimming pools are a wonderful way to relax and cool off, but they come with a certain level of maintenance. One of the most common and unavoidable maintenance concerns is water loss due to evaporation. Evaporation is the process by which water changes from a liquid to a gas or vapor. In a swimming pool, this happens when water molecules on the surface gain enough energy to escape into the air.
Factors Influencing Evaporation
Several environmental and pool-specific factors contribute to how quickly your pool loses water:
- Surface Area: The larger the exposed water surface, the more water is available to evaporate.
- Wind Speed: Wind blowing across the pool surface carries away humid air, replacing it with drier air. This increases the rate of evaporation. Think of how quickly clothes dry on a windy day.
- Temperature:
- Air Temperature: Warmer air can hold more moisture, and a significant difference between air and water temperature can drive evaporation.
- Water Temperature: Warmer water has more energetic molecules, making it easier for them to escape into the air as vapor.
- Relative Humidity: This is the amount of water vapor in the air compared to the maximum it can hold at a given temperature. When humidity is low, the air is dry and can readily accept more moisture from the pool surface, increasing evaporation. High humidity slows down evaporation.
- Sunlight/Solar Radiation: While not directly in this simplified calculator, direct sunlight provides energy that heats the water, thus increasing evaporation.
- Pool Cover: Using a pool cover, especially overnight, is the most effective way to reduce evaporation by creating a barrier between the water and the air.
Why Track Evaporation?
Monitoring your pool's evaporation rate helps you:
- Manage Water Costs: Regularly topping up your pool can be costly. Understanding how much you're losing helps you budget and potentially implement water-saving measures.
- Maintain Water Chemistry: As water evaporates, the concentration of dissolved chemicals (like chlorine, salt, and minerals) increases. Significant evaporation can lead to imbalanced chemistry, requiring more frequent adjustments.
- Optimize Pool Usage: Knowing your typical evaporation rate can help you plan when to refill or take measures to reduce loss, especially during hot, dry, or windy seasons.
Using the Calculator
Our calculator provides an estimated daily evaporation rate based on the key environmental factors you input:
- Pool Surface Area: The dimensions of your pool's water surface in square feet.
- Average Wind Speed: The typical wind speed over your pool area in miles per hour.
- Average Air Temperature: The average outdoor temperature in Fahrenheit.
- Average Water Temperature: The average temperature of your pool water in Fahrenheit.
- Average Relative Humidity: The typical humidity level in your area as a percentage.
The results will show you the estimated water loss in both gallons and inches per day. Remember, this is a simplified model. Actual evaporation can be influenced by other factors, and it's always a good idea to check your pool's water level regularly.
Reducing Evaporation
The most effective way to combat evaporation is by using a pool cover. Solar covers, safety covers, or even simple tarps can significantly reduce water loss by up to 95%. Other methods include:
- Reducing water temperature where possible.
- Minimizing water features like fountains or waterfalls when not in use, as they increase surface agitation and exposure.
- Planting hedges or installing windbreaks around the pool area to reduce wind exposure.
By understanding and managing your pool's evaporation, you can save water, maintain better water quality, and enjoy your pool more efficiently.