Air Change Rate (ACH) Calculator
The Air Change Rate (ACH) is a measure of how many times the air in a room or building is replaced with fresh outdoor air in one hour. It's a crucial metric for assessing indoor air quality, ventilation effectiveness, and energy efficiency.
Calculate ACH
.air-change-rate-calculator {
font-family: sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 500px;
margin: 20px auto;
background-color: #f9f9f9;
}
.air-change-rate-calculator h2 {
text-align: center;
color: #333;
margin-bottom: 15px;
}
.air-change-rate-calculator p {
color: #555;
line-height: 1.6;
margin-bottom: 20px;
}
.calculator-inputs {
margin-bottom: 20px;
display: grid;
grid-template-columns: 1fr;
gap: 15px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #444;
}
.input-group input[type="number"] {
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 1rem;
}
.input-group input[type="number"]:focus {
outline: none;
border-color: #007bff;
box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}
.air-change-rate-calculator button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #007bff;
color: white;
border: none;
border-radius: 5px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
}
.air-change-rate-calculator button:hover {
background-color: #0056b3;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
background-color: #e9ecef;
border: 1px solid #ced4da;
border-radius: 5px;
font-size: 1.1rem;
text-align: center;
color: #333;
min-height: 50px;
display: flex;
align-items: center;
justify-content: center;
}
function calculateACH() {
var roomVolumeInput = document.getElementById("roomVolume");
var airflowRateInput = document.getElementById("airflowRate");
var resultDiv = document.getElementById("result");
var roomVolume = parseFloat(roomVolumeInput.value);
var airflowRate = parseFloat(airflowRateInput.value);
if (isNaN(roomVolume) || isNaN(airflowRate) || roomVolume <= 0 || airflowRate <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for both fields.";
return;
}
// Formula: ACH = (Airflow Rate (CFM) * 60 minutes/hour) / Room Volume (cubic feet)
var ach = (airflowRate * 60) / roomVolume;
resultDiv.innerHTML = "Air Changes per Hour (ACH):
" + ach.toFixed(2) + " ";
}