.hr-calc-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 12px;
background-color: #ffffff;
box-shadow: 0 4px 15px rgba(0,0,0,0.05);
color: #333;
}
.hr-calc-container h2 {
color: #d32f2f;
text-align: center;
margin-bottom: 25px;
font-size: 28px;
}
.hr-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 25px;
}
.hr-field {
display: flex;
flex-direction: column;
}
.hr-field label {
font-weight: 600;
margin-bottom: 8px;
font-size: 14px;
color: #555;
}
.hr-field input, .hr-field select {
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 16px;
transition: border-color 0.3s;
}
.hr-field input:focus {
border-color: #d32f2f;
outline: none;
}
.hr-btn {
grid-column: span 2;
background-color: #d32f2f;
color: white;
padding: 15px;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s;
}
.hr-btn:hover {
background-color: #b71c1c;
}
.hr-result-box {
margin-top: 25px;
padding: 20px;
background-color: #fbe9e7;
border-radius: 8px;
border-left: 5px solid #d32f2f;
display: none;
}
.hr-result-item {
margin-bottom: 10px;
font-size: 18px;
}
.hr-result-value {
font-weight: bold;
color: #d32f2f;
}
.hr-article {
margin-top: 40px;
line-height: 1.6;
color: #444;
border-top: 1px solid #eee;
padding-top: 30px;
}
.hr-article h3 {
color: #333;
font-size: 22px;
margin-top: 25px;
}
.hr-article table {
width: 100%;
border-collapse: collapse;
margin: 15px 0;
}
.hr-article th, .hr-article td {
border: 1px solid #ddd;
padding: 12px;
text-align: left;
}
.hr-article th {
background-color: #f9f9f9;
}
@media (max-width: 600px) {
.hr-grid {
grid-template-columns: 1fr;
}
.hr-btn {
grid-column: span 1;
}
}
Heating Rate & Power Calculator
Mass of Substance (kg)
Specific Heat Capacity (J/kg·°C)
Initial Temperature (°C)
Final Temperature (°C)
Time Elapsed (Minutes)
System Efficiency (%)
Calculate Heating Requirements
Heating Rate:
Total Heat Energy:
Required Power:
Power in Kilowatts:
Understanding Heating Rate and Thermal Energy
The heating rate is a measure of how quickly the temperature of a specific substance increases over a period of time. This metric is crucial in fields such as chemical engineering, food processing, HVAC design, and materials science. Understanding the heating rate allows engineers to size heaters correctly and ensure safety protocols are met.
The Math Behind the Calculation
To calculate the thermal energy and the power required, we use the primary thermodynamic formula for sensible heat:
Q = m × c × ΔT
Q : Total heat energy (Joules)m : Mass of the substance (kg)c : Specific heat capacity (J/kg·°C)ΔT : Change in temperature (Final Temp – Initial Temp)
The Heating Rate is simply the change in temperature divided by time (ΔT / t). The Power (P) is the energy divided by time in seconds, further adjusted for system efficiency.
Common Specific Heat Capacities
Substance
Specific Heat (J/kg·°C)
Water
4,184
Air (Room Temp)
1,006
Aluminum
897
Copper
385
Iron
450
Example Calculation
Suppose you want to heat 50 kg of water from 20°C to 80°C in 15 minutes with a system that is 90% efficient.
ΔT: 80 – 20 = 60°CEnergy (Q): 50 kg × 4184 J/kg·°C × 60°C = 12,552,000 JoulesTime in Seconds: 15 × 60 = 900 secondsTheoretical Power: 12,552,000 / 900 = 13,946.67 WattsActual Power (90% Efficiency): 13,946.67 / 0.9 = 15,496.3 Watts or 15.5 kWHeating Rate: 60°C / 15 min = 4°C/min
function calculateHeating() {
var mass = parseFloat(document.getElementById('mass').value);
var specHeat = parseFloat(document.getElementById('specHeat').value);
var tStart = parseFloat(document.getElementById('tempStart').value);
var tEnd = parseFloat(document.getElementById('tempEnd').value);
var timeMin = parseFloat(document.getElementById('timeElapsed').value);
var eff = parseFloat(document.getElementById('efficiency').value);
if (isNaN(mass) || isNaN(specHeat) || isNaN(tStart) || isNaN(tEnd) || isNaN(timeMin) || isNaN(eff) || timeMin <= 0 || eff <= 0) {
alert("Please enter valid positive numerical values for all fields.");
return;
}
var deltaT = tEnd – tStart;
var heatingRate = deltaT / timeMin;
// Total Joules needed
var energy = mass * specHeat * deltaT;
// Power (Watts = Joules / Seconds)
var timeSec = timeMin * 60;
var powerWatts = energy / timeSec;
// Adjust for efficiency
var realPowerWatts = powerWatts / (eff / 100);
var realPowerKw = realPowerWatts / 1000;
// Display Results
document.getElementById('hrResult').style.display = 'block';
document.getElementById('resRate').innerText = heatingRate.toFixed(2);
document.getElementById('resEnergy').innerText = energy.toLocaleString(undefined, {maximumFractionDigits: 0});
document.getElementById('resPower').innerText = realPowerWatts.toLocaleString(undefined, {maximumFractionDigits: 2});
document.getElementById('resKw').innerText = realPowerKw.toFixed(3);
}