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Air Changes Per Hour Solver

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Input Parameters

Unit System

Room Dimensions

Volume: 3,000 cu ft

ACH Requirements by Room Type

Office Space4-6 ACH
Residential Living4-8 ACH
Commercial Kitchen10-15 ACH
Bathroom/Restroom8-12 ACH
Classroom4-6 ACH
Laboratory6-12 ACH
Hospital Room6-15 ACH
Warehouse/Storage2-4 ACH

ACH Analysis

Air Changes Per Hour

40
ACH ACH

Compliance Status

Above typical range - may be over-ventilated
Airflow is higher than typical for this space type

Flow Analysis

Room Volume3,000 cu ft
Airflow2,000 CFM
Airflow (CMH)3,398 CMH
Average Velocity6.67 FPM

Required Airflow Range

Minimum Required200 CFM
Maximum Typical300 CFM
Current Airflow2,000 CFM

Air Distribution Notes

• Ensure adequate mixing for uniform air distribution
• Consider supply and return air placement
• Account for room pressurization requirements
• Low velocity - ensure adequate mixing

ACH Requirements Analysis

Detailed Air Change Analysis

Ventilation Analysis

Room Type:Office Space
Floor Area:300 ft²
Ceiling Height:10 ft
Air Turnover Time:1.5 min

Performance Metrics

CFM per ft²:6.67
Air Velocity:6.7 FPM
Mixing Factor:Poor
Draft Risk:Low

System Recommendations

• Consider reducing airflow for energy savings
• Improve air distribution design
• Consider demand-controlled ventilation

Room Type ACH Requirements

Room TypeMin ACHMax ACHYour ACHStatus
Office Space4640.0Over-ventilated
Residential Living48-
Commercial Kitchen1015-
Bathroom/Restroom812-
Classroom46-
Laboratory612-
Hospital Room615-
Warehouse/Storage24-

Air Changes per Hour Calculation Steps

1

Calculate Room Volume

Formula:
V=L×W×HV = L \times W \times H
Calculation:
V=20×15×10V = 20 \times 15 \times 10
Result:
3000 cu ft3000 \text{ cu ft}
2

Calculate Air Changes per Hour

Formula:
ACH=QCFM×60VACH = \frac{Q_{CFM} \times 60}{V}
Calculation:
ACH=2000×603000ACH = \frac{2000 \times 60}{3000}
Result:
40.0 ACH40.0 \text{ ACH}
3

Convert Airflow to Cubic Meters per Hour

Formula:
QCMH=QCFM×1.699Q_{CMH} = Q_{CFM} \times 1.699
Calculation:
QCMH=2000×1.699Q_{CMH} = 2000 \times 1.699
Result:
3398 m³/hr3398 \text{ m³/hr}
4

Calculate Average Air Velocity

Formula:
v=QCFMAfloorv = \frac{Q_{CFM}}{A_{floor}}
Calculation:
v=2000300v = \frac{2000}{300}
Result:
6.7 FPM6.7 \text{ FPM}
5

Check Compliance with Standards

Formula:
Required: 4 to 6 ACH\text{Required: } 4 \text{ to } 6 \text{ ACH}
Calculation:
Actual: 40.0 ACH\text{Actual: } 40.0 \text{ ACH}
Result:
Abovetypicalrange−maybeover−ventilated Above typical range - may be over-ventilated \text{ }