Rate of Heat Loss Calculator
This calculator helps you estimate the rate of heat loss from a building. Understanding heat loss is crucial for optimizing insulation, HVAC system sizing, and energy efficiency. The calculation is based on the U-value (thermal transmittance) of building elements, their surface area, and the temperature difference between the inside and outside environments.
Estimated Rate of Heat Loss:
Understanding Heat Loss
The rate of heat loss (Q) through a building element is determined by the following formula:
Q = U × A × ΔT
- Q is the rate of heat loss, measured in Watts (W). This represents the amount of energy that escapes the building per second.
- U is the U-value (thermal transmittance) of the building element. It measures how effectively a material conducts heat. A lower U-value indicates better insulation and less heat transfer. It is measured in Watts per square meter per Kelvin (W/m²K).
- A is the surface area of the building element (e.g., wall, window, roof) through which heat is being lost. It is measured in square meters (m²).
- ΔT is the temperature difference between the inside and outside of the building. It is calculated as: Indoor Temperature – Outdoor Temperature (°C or K). A larger temperature difference results in a higher rate of heat loss.
By calculating the heat loss through different parts of your building and summing them up, you can get a total estimate of your building's thermal performance. This information is vital for selecting appropriate heating systems and improving energy efficiency.
function calculateHeatLoss() {
var uValue = parseFloat(document.getElementById("uValue").value);
var area = parseFloat(document.getElementById("area").value);
var indoorTemp = parseFloat(document.getElementById("indoorTemp").value);
var outdoorTemp = parseFloat(document.getElementById("outdoorTemp").value);
var resultDiv = document.getElementById("heatLossOutput");
if (isNaN(uValue) || isNaN(area) || isNaN(indoorTemp) || isNaN(outdoorTemp)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
var deltaT = indoorTemp – outdoorTemp;
var heatLoss = uValue * area * deltaT;
if (heatLoss < 0) {
// This could happen if outdoor temp is higher than indoor, which means heat is gained, not lost.
// For this calculator, we focus on heat loss, so we'll indicate no net loss or handle as appropriate.
resultDiv.innerHTML = "Indoor temperature is not higher than outdoor temperature; no net heat loss calculated.";
} else {
resultDiv.innerHTML = heatLoss.toFixed(2) + " W";
}
}
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font-family: sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
background-color: #f9f9f9;
}
.heat-loss-calculator h2, .heat-loss-calculator h3 {
text-align: center;
color: #333;
margin-bottom: 20px;
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transition: background-color 0.3s ease;
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.heat-loss-calculator button:hover {
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#result {
text-align: center;
}
#heatLossOutput {
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.calculator-explanation li {
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}
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}