Air Mover Placement
How many air movers a water loss needs, low and high, from the IICRC worksheet.
Example
You enter
- Wet floor area (ft²) 600
- Water class 2
- Affected rooms 1
- Wet wall and ceiling above 2 ft (ft²) 0
- Wall insets and offsets over 18 in 0
You get
- Air mover count 10
- Air mover count high 13
- Total CFM 25000
- CFM per ft² 41.667
- Placement pattern continuous perimeter
Checked against published worked examples from: IICRC Airmover and Gallons Calculation Worksheet (US imperial, rev. 7.1.22).
Details, formula, and sources
ScopeOne per room, per 50-70 ft² of wet floor, per 100-150 ft² of wet wall and ceiling, and per inset.
Formula or tablelow = rooms + ceil(wet_floor_ft2 / 70) + ceil(wet_wall_ceiling_ft2 / 150) + insets; high = rooms + ceil(wet_floor_ft2 / 50) + ceil(wet_wall_ceiling_ft2 / 100) + insets. The wet-floor figure includes the lower walls to 2 ft. total_cfm = low count x 2,500 cfm nominal.
Source and editionIICRC Airmover and Gallons Calculation Worksheet, US imperial (rev. 7.1.22), which accompanies IICRC S500; S500 itself by name.
Free accessThe worksheet is free at iicrc.org; the S500 standard is licensed.
What governsEstimate. AHJ and licensed professional govern.
API field namesaffected_area_ft2, water_class, rooms, wall_ceiling_ft2, insets, air_mover_count, air_mover_count_high, total_cfm, cfm_per_ft2, placement_pattern
- Coverage 1 per room + 1 per 50-70 ft² wet floor + 1 per 100-150 ft² wet wall/ceiling above 2 ft + 1 per inset/offset over 18 inIICRC Airmover Worksheet rev. 7.1.22
- Unit airflow 2,500 cfm nominal per air mover (for the CFM total only)typical axial unit; the rating plate governs