How many negative-air machines do I need for a containment?

Compute containment volume (length x width x height), multiply by your target air changes per hour, and divide by 60 for the required CFM. This tool does that, then divides by a stocked HEPA negative-air machine’s rated airflow to give a machine count. Four ACH is the common containment minimum; higher hazard or faster clearance uses 6 to 8.

What negative pressure should the containment hold?

The standard target is -0.02 inches water column across the critical barrier, maintained by continuous HEPA-filtered negative air with adequate make-up air, per OSHA 29 CFR 1926.1101 for asbestos. Lead and mold containments follow the same negative-pressure practice.

Two abatement workers in white Tyvek coveralls, hard hats, and respirators inside a derelict industrial hall, one bagging asbestos into a hazardous-material disposal bag while the other sprays down a wall, beside a DANGER: ABATEMENT WORK sign

EPA / OSHA CONTAINMENT METHOD

Size the containment before you build it.

Enter the containment. Get a negative-air, HEPA filtration, and critical-barrier poly plan matched to in-stock Stampede units, ready to quote.

How this estimate works

This tool is a planning estimate built on published EPA/OSHA containment methodology: required airflow by the volume x air-changes method (4 ACH minimum, per AIHA and OSHA 29 CFR 1926.1101 negative-pressure enclosures at -0.02" WC), and critical-barrier poly by the 6-mil floor-double-layer practice. Actual counts depend on containment integrity, make-up air, and the certified technician’s monitoring. Stampede is a distributor, not an abatement contractor. The abatement contractor makes the final determination.

Abatement

Negative-air & containment calculator

Every recommendation is an in-stock Stampede unit. No prices shown, request a quote and a rep confirms availability and pricing.

Area 1Length (ft)Width (ft)Ceiling (ft)

Hazard typeTarget air changes/hrCrew size (optional)

Enter the containment dimensions, hazard type, and target air changes to size the negative-air plan.

The Method

From air sampling to clearance

The calculator sizes the plan. Here is the full containment workflow it feeds, from air sampling and containment build to negative pressure, removal, and clearance.

EPA and OSHA containment methodology diagram for negative air and abatement science: a sealed abatement work zone with 6-mil poly barrier walls, HEPA negative-air machines exhausting to outside for a minimum of 4 air changes per hour, differential pressure monitoring at -0.02 inches water column via manometer, a multi-stage decontamination airlock, and a respirator-clad technician taking readings, labeled to OSHA 29 CFR 1926.1101 compliance.

Planning by trade

Building your stack for another vertical?

Abatement is the live calculator here. Water-damage drying has its own tool; every other vertical links to its equipment guide, more calculators are on the way.

Restoration

Live tool