Stairwell Pressurization Testing
When It's Required, How It's Tested, and the Tools You Need
In a tall building the stair is the way out, and it only works if smoke stays out of it. A pressurization system pushes outdoor air into the stair so that air leaks out through the doors instead of smoke leaking in. This guide covers which codes require it, the pressure and door-force limits (and why the two fight each other), how often it has to be tested, what a complete test looks like, and the instruments a testing team brings.
Why this exists at all
In a high-rise fire the stair is the way out for everyone above the fire floor, and it is also the way in for firefighters. Elevators are recalled, so people walk down past the fire floor. Each floor has a door into the stair. Every time one of those doors opens, and every gap around every door, is a path for smoke.
Stair pressurization answers that with air. A dedicated fan blows outdoor air into the stair and holds it at a slightly higher pressure than the floors. Air then leaks out of the stair through the door gaps and through any door that opens, and smoke has to push against that flow to get in.
Two limits fight each other. Too little pressure and smoke gets in. Too much and a person on the floor side cannot pull the door open against it. The whole design, and most test failures, come down to keeping the stair inside that window on every floor, in summer and winter, with doors opening and closing.
When it is required
No code says “pressurize this stair.” The codes require a smokeproof enclosure, and pressurization is one of the allowed ways to build one.
High-rise buildings
Every required interior exit stairway serving floors more than 75 ft above the lowest level of fire-department vehicle access must be a smokeproof enclosure. IBC §403.5.4 Note the wording: it is the stair that serves those upper floors, so a high-rise can have a short stair that only serves the lower floors and needs no pressurization.
Underground buildings and control towers
Every required stairway serving floors more than 30 ft below the level of exit discharge must be a smokeproof enclosure, IBC §405.7.2 and the IBC applies the same rule to airport traffic control towers. The chapter 10 section that collects these triggers is §1023.11 in the 2018 IBC and §1023.12 in the 2024 IBC.
NFPA 101
In the Life Safety Code, §7.2.3 applies where another section of the Code requires a smokeproof enclosure, and it says how to build one. Its pressurization rule (§7.2.3.9) is different from the IBC’s: at least 0.05 in. of water in a sprinklered building, 0.10 in. in a nonsprinklered one, held under likely stack and wind conditions, and never so high that a door needs more than 30 lb to start opening. NFPA 101 §7.2.3.9.1 The 2024 edition adds that a pressurized enclosure must follow NFPA 92.
Other smoke control systems
Atria (IBC §404.5), some underground buildings and some healthcare designs have smoke control systems of their own. Those are designed and tested under IBC §909 and NFPA 92 too, often together with the stair fans and controlled from the same firefighter’s panel.
The ways to build a smokeproof enclosure
IBC §909.20 lists the options. Every one starts the same way: a stair enclosed in 2-hour construction, doors that are self-closing or close automatically when a smoke detector at the floor entrance trips (and when one closes, they all close), ventilation or pressurization equipment that is separate from the building HVAC and protected by 2-hour construction, and standby power for the fans and the detection. The edition changes the numbering:
| Option | 2018 IBC | 2024 IBC | What it needs |
|---|---|---|---|
| Natural ventilation | §909.20.3 | §909.20.3 | Open exterior balcony, or a vestibule with at least 16 sq ft of opening to an outside court or yard at least 20 ft wide. |
| Mechanically ventilated vestibule | §909.20.4 | Not in the list | Vestibule with 1 air change per minute supply and 150 percent exhaust, a 20 in. smoke trap, and the stair at 0.10 in. above the vestibule. |
| Stair pressurization | §909.20.5 | §909.20.4 | Building sprinklered throughout (NFPA 13). No vestibule. Stair held at 0.10 to 0.35 in. of water above the building, measured with all stair doors closed under the worst expected stack and wind. |
| Pressurized stair and vestibule | Not in the 2018 edition | §909.20.5 | Stair and vestibule both pressurized: 0.05 in. of water across the stair-to-vestibule door and 0.05 in. across the vestibule-to-floor door, doors closed. |
Sources: 2018 IBC text and ICC’s 2024 viewer. The quoted pressures are the code minimums and maximums; the approved design states the actual target range for your building.
How the system works — a real one, top to bottom
The photos below are one hospital tower stair. The fan sits at the top of the stair, takes outdoor air, and blows it into a plenum. Two round ducts drop from the plenum down through the stair and let air out through grilles at the landings. Supplying air at several levels instead of one point is called multiple injection.
The fan, plenum and the two supply risers leaving it. The red pipe on the left is the standpipe, which shares the stair. Note the sprinkler piping and the fire alarm wiring in conduit.
The two risers each carry a motorized damper (the orange actuators). Dampers are part of the system: they are exercised in the test and their position is confirmed on the panel. A stuck damper starves every floor below it.
Supply grilles at a landing. Each grille’s airflow is measured during acceptance and compared with the design. Anything hung on or stored against a grille changes the balance.
The stencil is a reminder of the other half of the system: the stair is a 2-hour enclosure. Every unsealed penetration in that wall is a leak that the fan has to make up for.
Single injection or multiple injection
A single-injection system blows all the air in at one point, usually the top or the bottom. It is simple, but in a tall stair the floors near the fan get too much pressure and the far floors too little, and one open door near the injection point can dump most of the air. Multiple injection (the system in the photos) feeds air at many levels so the pressure is more even. The engineering literature gives height rules of thumb for when single injection stops working; the real answer is in the design calculation for the building, which accounts for stack effect.
Keeping the pressure in the window
With every door closed the air has nowhere to go and the pressure climbs; with several doors open it falls. Systems handle this in one of three ways: a barometric relief damper that opens to let excess air out, a variable-speed fan controlled by a pressure sensor in the stair, or a bypass damper around the fan. Whichever is used, it is the part most likely to drift. A relief damper that sticks closed gives you doors that fail the force test; one that sticks open gives you a stair that never reaches minimum pressure.
What starts it, and what stops it
The fan starts on a smoke detector at the floor entrance to the stair (NFPA 101 §7.2.3.10 puts it within 10 ft of each entrance), on sprinkler waterflow or general alarm where those are provided, and by manual control for the fire department. It runs on standby power.
The fan must not blow smoke into the stair. Georgia’s fire code amendments require a smoke detector at each pressurization intake that shuts that fan down when it sees smoke. Building HVAC also matters: a return-air system pulling from the floors next to the stair can draw stair air out, so the fire alarm sequence puts the HVAC in its fire mode. Fan shutdown relays and smoke dampers are part of the same test.
A firefighter’s smoke control panel. Each fan has a Run / Auto / Stop switch with status lights, and there is a relief fan, an elevator hoistway pressurization fan and a master switch. In the test, every switch position is tried and the status light must show what the equipment actually did, not just what was commanded. Hospital name removed.
Door force: the limit that decides the design
IBC §1010.1.3 and NFPA 101 §7.2.1.4.5 set three limits for an egress door, all measured at the latch side:
- 15 lb to release the latch (the 2024 IBC adds 28 inch-pounds for hardware you turn).
- 30 lb to set the door in motion. This is the one the pressure affects most.
- 15 lb to swing it fully open (NFPA 101: to the minimum required width).
NFPA 101 allows 50 lb for existing doors in existing buildings, which is the limit CMS applies to an existing hospital stair under the 2012 edition. New construction and the IBC use 30 lb.
The pressure pushes on the whole face of the door, but you pull at the latch edge, so only part of it reaches your hand. The standard door equation (2024 IBC §909.6.2, also in NFPA 92’s annex) gives the force at the knob: the closer force, plus 5.2 × width × area × pressure ÷ (2 × (width − distance from the edge to the knob)), with feet and inches of water. The table shows only the pressure part, for a 7 ft door with the knob 3 in. from the edge:
| Pressure (in. of water) | 36 in. door | 44 in. door | |
|---|---|---|---|
| 0.05 | 3.0 lb | 3.6 lb | NFPA 101 / NFPA 92 minimum for a sprinklered building |
| 0.10 | 6.0 lb | 7.2 lb | IBC stair-pressurization minimum |
| 0.25 | 14.9 lb | 17.9 lb | |
| 0.35 | 20.8 lb | 25.1 lb | IBC stair-pressurization maximum |
Pressure part of the opening force only. Add the door closer, typically 6 to 10 lb at the latch side depending on its size and adjustment.
That explains the IBC’s 0.35 in. ceiling: about 21 lb from pressure on a standard door, plus a typical closer, lands right at 30 lb. A wide door or a heavy closer fails first. It also explains why stack effect matters. In winter the stair is warmer than outside, so pressure inside the stair is highest at the top; doors near the top can fail the force test while doors near the bottom barely make the minimum pressure.
How often, and by whom
Acceptance (before occupancy)
Smoke control systems are a special inspection. IBC §909.18.8, §1705.18 (2018) / §1705.19 (2024) The approved agency must have expertise in fire protection engineering and mechanical engineering and be certified as air balancers. Testing happens twice: during duct installation (leakage, device locations) and at completion (pressure differences, flows, detection and controls). The agency writes a report listing every device with its design and measured values; the responsible registered design professional reviews it and signs, seals and dates it when satisfied; a copy goes to the fire code official and an identical copy stays at the building. Both editions also have the smokeproof enclosure equipment tested in the presence of the building official (§909.20.6.3). No certificate of occupancy until the fire code official accepts it and the fire department has been trained on the system (§909.19).
Ongoing (the part most buildings get wrong)
The International Fire Code governs maintenance, in §909.22 of the 2024 edition (§909.20 in 2018; the 2024 IFC uses §909.20 for smokeproof enclosures). NFPA 92 §8.6 sets the same intervals. A written schedule starts right after acceptance, and records show the date, who did the work, any problems and what was done about them. Then:
- Dedicated systems (equipment used only for smoke control, which describes almost every stair pressurization fan): every control sequence operated every six months, on standby power.
- Nondedicated systems (sharing building HVAC): every control sequence once a year, on standby power.
- A dedicated system runs an automatic weekly self-test that reports problems (IBC §909.12.1). Any component that weekly test does not exercise is tested every six months.
“On standby power” means the generator actually carries the fans during the test. A test run only on utility power does not meet the section.
Who does the periodic tests
The IFC requires records but does not name a qualification for the periodic tests; NFPA 92 asks for people thoroughly knowledgeable in the system. In practice the owner hires a TAB firm certified by AABC, NEBB or TABB to take the pressure and door-force readings, working with the fire alarm contractor (to start the sequences) and the controls contractor (fans, dampers, VFDs). A good TAB report states plainly that the firm is not the AHJ; someone responsible for the building still has to compare the readings with the approved design and fix what failed. Some AHJs require a licensed engineer’s statement; ask.
Healthcare
CMS surveys engineered smoke control systems under K-0771: in new healthcare occupancies they are tested per NFPA 92, in existing ones per established engineering principles, and the test records are kept on site (NFPA 101-2012 §18.7.7 / §19.7.7). Stairs and smokeproof enclosures themselves fall under K-0225. The Joint Commission reviews the same records under its Physical Environment chapter, which replaced the Environment of Care and Life Safety chapters on January 1, 2026.
Tools for stair pressurization testing
This is what a testing team brings. Each instrument should carry a current calibration certificate, and the certificates go in the report: a reading from an instrument nobody can show was calibrated is easy to challenge.
Reads the pressure difference across each stair door. One port open to the stair, the other connected by tubing to the floor side (run under or beside the closed door, or through a test port).
Needs to read to 0.001 in. of water and average over time; readings in a stair bounce with every door and gust. A dial gauge cannot resolve the difference between 0.08 and 0.10.
A push-pull gauge with peak hold, applied at the latch side, square to the door. Record three numbers per door: latch release, set in motion, and fully open.
Pull slowly and steadily. A jerk adds force that is not really there; a hand on the lever helping the latch hides a sticky latch.
Pitot tube and duct traverse for total fan airflow; a flow hood or rotating-vane anemometer for each supply grille; a hot-wire anemometer for air speed through an open door when the design calls for it.
Compare with the design values in the acceptance report. A fan running at 70 percent of design airflow can still make pressure on a calm day and fail on a cold, windy one.
Fan speed (optical or contact tachometer), motor amps and volts, and VFD speed. Confirms the fan is doing work, not just turning, and that it runs on generator power.
Check rotation direction too. A fan that was rewired backwards still moves some air and still shows “Run” on the panel.
Inside-stair and outdoor temperature plus wind speed and direction at the time of the test. Stack effect depends on the temperature difference, so readings mean little without them.
The code criterion is “under maximum anticipated stack and wind.” A mild-day test is not that; the design calculation fills the gap, so record the conditions.
The person at the smoke control panel or fire alarm panel, the person in the stair and the person at the fan all need to talk. Doors are opened and closed on command during door-open scenarios.
Check coverage in the stair first. Concrete stair shafts kill weak radios.
Door bottom clearance (¾ in. maximum under NFPA 80, 2013 ed. §4.8.4.1), gaps at the frame and meeting edges, and a look at closers, latches and seals on every door.
Worn gaskets and big undercuts are the quiet reason a stair needs more fan than it used to.
A smoke pencil or puffer to show which way air moves at a door gap, a penetration or a damper. Good for finding leaks and for showing the owner what “positive pressure” looks like.
Coordinate first: visible smoke near a detector will start an alarm. Never fill a stair with test smoke without the AHJ and the fire alarm contractor in on it.
Approved sequence of operations, the rational analysis or design values, mechanical and fire alarm drawings, the last acceptance report, and a floor-by-floor test form.
Our interactive test checklist has a per-floor table that flags readings outside the design range.
The test, step by step
Run what the approved design and test procedure say. The outline below is the common shape of a periodic test of a dedicated stair system:
- Prepare. Notify the monitoring company and the occupants, put the fire alarm system in test with the alarm contractor, and have the sequence of operations, the design values and the last report in hand. Confirm the generator transfer is part of the plan.
- Start it the real way. Trip the smoke detector at a stair entrance (or the input the design names) rather than just switching the fan on. Confirm every door in the enclosure closes, the fan starts, dampers move, and building HVAC goes to its fire mode. Time how long the fan takes to reach speed.
- Check the firefighter’s panel. Each switch position (Auto, Run, Stop) must control the equipment and the status lights must match what the equipment did.
- All doors closed, every floor. Once the stair settles, read the pressure difference across the door on every floor and record the stair, floor, time and reading. Compare each with the design range.
- Door forces, every floor. With the fan running, measure latch release, set in motion and full open at each door. Then release the door from full open and confirm it closes and latches on its own.
- Door-open scenarios, if the design has them. Many designs and acceptance procedures require the system to hold pressure with one or more doors open, for example the exit discharge door and the fire floor door. Open the doors the procedure names, read the remaining floors, and write down which doors were open and which document required it.
- Relief and controls. Watch the relief damper, bypass or VFD respond as doors open and close. Confirm the pressure sensor reading at the controller agrees with your manometer.
- Airflow and fan data. Fan airflow, speed, amps and volts against the design and the last report.
- On standby power. Repeat the sequence with the generator carrying the load (2024 IFC §909.22.4 for dedicated systems; §909.20.4 in 2018). Check the intake smoke detector shuts the fan down.
- System off. With the fans stopped, every stair door must still close and latch by its closer alone. Pressurization is not allowed to be the thing that shuts the door.
- Restore and report. Reset the systems, return HVAC to normal, take the alarm system out of test, and write the report: every reading next to its design value, every deficiency, the corrective action and the retest.
Doors open or closed?
This is the question we hear most. The IBC criterion for stair pressurization is measured with all stair doors closed; the 0.10 to 0.35 in. range is a closed-door number. That is the minimum the code itself sets.
Door-open conditions come from somewhere else: the project’s rational analysis, the acceptance test procedure, or the AHJ. NFPA 92 used to require designs and tests to account for a “design number” of open doors. Its 2021 edition narrowed that, for stair pressurization and smoke containment, to doors that open automatically as part of the smoke control strategy (from the publisher’s summary of the 2021 changes). Older designs built to earlier editions still carry their door-open scenarios. They are common. Many designs require the stair to keep a minimum pressure, or a minimum airflow through an open door, with the exit discharge door and one or more floor doors open, because that is what happens in a real evacuation. If your design has those scenarios, they are part of every test. If it does not, do not invent pass/fail criteria for them, but you can still run one as information.
Either way, the report should say which doors were open, on which floors, and which document required it.
Georgia: what applies
Georgia enforces the 2024 IBC and IFC with state amendments from January 1, 2026, and the 2018 editions before that. In the 2024 IBC the stair pressurization alternative is §909.20.4 (it was §909.20.5 in 2018). The requirement did not change: a sprinklered building, no vestibule, the stair held at 0.10 to 0.35 in. of water above the building with all interior exit stair doors closed, under the worst expected stack and wind conditions.
Georgia’s Rule 120-3-3 amends IFC §909. In the 2020 edition of the rule the amendments: apply the smoke control section to systems required by the Life Safety Code as well as the building and fire codes; name NFPA 92, NFPA’s Smoke Control in Fire Safety Design, the ASHRAE/SFPE Design of Smoke Management Systems and ASHRAE Guideline 5 (commissioning) as the accepted engineering references; and require a smoke detector at each pressurization intake that shuts the fan down when it detects smoke. Confirm the wording in the rule now in force.
Healthcare facilities that take Medicare or Medicaid add the CMS layer on top: NFPA 101 and NFPA 99, 2012 editions, with K-0771 for smoke control testing records.
What a complete record contains
A TAB report alone is not a complete smoke control record. Use this list as a “do we have it?” check.
A. Design basis
- Building, stairs, floors served, code of record
- Which design alternative was used (stair pressurization, stair and vestibule, ventilated vestibule, balcony)
- The approved rational analysis: stack and wind assumptions, required pressure range, door-force criteria, door-open scenarios
- Fan, relief and damper design values
- Fire alarm and smoke control sequence of operations; firefighter’s panel description
B. Acceptance
- Special inspection report by the approved agency (IBC §909.18.8.3): every device with manufacturer, nameplate data, design value and measured value
- Review, signature, seal and date by the responsible registered design professional
- Proof the report was filed with the fire code official (§909.18.8.3.1), and the identical copy kept at the building
- Drawings and documents locating every component and describing its function and maintenance (§909.18.9); devices tagged with the date of their last successful test
- The written maintenance program the fire code official approved (§909.19)
C. Every periodic test
- Date, the people who did the work, and what was tested (2024 IFC §909.22.2; §909.20.2 in 2018)
- Test conditions: doors open or closed and why, HVAC state, fan and VFD status, standby power, temperatures and wind
- Floor-by-floor pressure readings and three door-force readings per door; self-close and latch result
- Fan airflow, speed, amps, volts; damper operation; relief operation; intake detector shutdown
- Deficiencies, corrective action, parts replaced, retest results
- Instrument calibration certificates
Request to send your contractor or engineer
If all you have is a TAB report, this is the request to send. Change the building references to suit.
“Please provide the complete smoke control / stair pressurization record for [building / stair], including the approved rational analysis and design pressure range, the sequence of operations, the acceptance test procedure and special inspection report, the registered design professional’s signed and sealed review, and evidence the report was filed with the fire code official.
For the periodic tests, please confirm the system is tested at the IFC maintenance frequency for its type (2024 IFC §909.22) (semiannually for a dedicated system) and on standby power, and provide the floor-by-floor pressure and door-force readings compared with the design values, the intake smoke detector shutdown check, and the corrective actions for any failures.
Please also confirm whether readings were taken with all stair doors closed. If any door-open scenario was tested, identify the doors and the document that requires that scenario.”
Common failures
- Tested once a year on utility power. A dedicated system is due every six months, on the generator.
- Relief damper stuck. Closed: door forces too high on the upper floors. Open: the stair never reaches minimum pressure.
- Fan delivering less air. Slipping belts, dirty intake screens, worn bearings, wrong rotation. The panel says “Run” and the stair is under pressure on a calm day only.
- Motorized dampers not moving. Actuators fail quietly because they move only during tests and fires.
- Door closers and latches. A door that only latches because the fan pushes it shut has a hardware problem the pressurization was hiding. Test the doors with the system off.
- Doors propped open. A propped stair door defeats the enclosure. Hold-opens are allowed only where they release on the smoke detector.
- Leaks. Bottom clearance beyond ¾ in. (NFPA 80), worn gaskets, unsealed pipe and conduit penetrations in the 2-hour enclosure. See firestopping.
- HVAC still running. A return fan on the floor next to the stair pulls stair air out and drops the pressure; check the fire-mode interlocks during the same test.
- Panel shows the command, not the result. Status lights must come from proof devices (airflow switches, damper end switches), not from the command output.
- Records that cannot answer the questions. No design values to compare with, no list of which doors were open, no calibration certificates, no record of the generator part.
Healthcare notes
- Defend in place. Hospitals move patients horizontally through smoke compartments first; the stairs are the second stage. The smoke control sequence has to fit that plan, and staff should know what the stair fans do.
- Pressure-sensitive rooms. Operating rooms, isolation rooms and pharmacies have their own pressure requirements. Check that stair pressurization and the fire-mode HVAC changes do not upset them.
- Moving patients in stairs. Evacuation chairs and sleds need doors that staff can open while handling a patient. Door force is a staff-safety issue as well as a code one.
- Survey records. Keep the last acceptance report, the periodic test records and the corrective actions together; K-0771 asks for documentation on the premises.
Watch: AABC TAB Talk — Mastering Stairwell Pressurization
A detailed seminar from the Associated Air Balance Council, told from the point of view of the air-balancing engineer who walks the stair with the manometer and the door gauge. AABC is one of the three U.S. bodies, with NEBB and TABB, that certify the firms who do this testing. It pairs well with the tools and step-by-step sections above.
Courtesy of AABC. Starts at the test-procedure part of the talk.
Owner and facility-manager checklist
- Know whether your system is dedicated or nondedicated, and test at the IFC frequency: semiannually for dedicated, annually for nondedicated.
- Every test includes a run on standby power.
- The weekly automatic self-test is running and its trouble reports are being read.
- Every floor of every stair is read, not a sample.
- Pressure on every floor is inside the design range (for an IBC stair-pressurization design, 0.10 to 0.35 in. of water with doors closed).
- Door forces at every door: 15 lb latch, 30 lb to start, 15 lb to full open.
- Every door closes and latches with the system off.
- Relief damper, VFD and motorized dampers verified moving.
- Intake smoke detectors shut the fans down.
- Firefighter’s panel switches and status lights verified.
- No propped stair doors; bottom clearances and gaskets in good order.
- The acceptance report, design values and every periodic test record kept at the building.
Frequently Asked Questions
When is stairwell pressurization required?
What pressure difference is required?
How often must a stair pressurization system be tested?
What is the 30-pound rule?
How much force does the pressure put on the door?
Who is allowed to run the test?
What tools are used to test stair pressurization?
What is the difference between a smokeproof enclosure, a pressurized stair and a pressurized vestibule?
References
1. International Building Code, 2018 and 2024 editions: §403.5.4, §405.7.2, §909.6.2 (door-force equation, 2024), §909.12.1, §909.18.8, §909.19, §909.20, §1010.1.3, §1023 (smokeproof enclosures), §1705.18 (2018) / §1705.19 (2024). Section numbers checked against the 2018 text and ICC’s 2024 viewer. Georgia enforces the 2024 edition with state amendments from January 1, 2026; buildings permitted earlier were designed to the 2018 edition.
2. International Fire Code: Maintenance, §909.20 in the 2018 edition and §909.22 in the 2024 edition (schedule, records, dedicated systems semiannually, nondedicated annually, components bypassed by the weekly test semiannually, all on standby power).
3. NFPA 92, Standard for Smoke Control Systems, 2021 and 2024 editions: Table 4.4.2.1.1 minimum design pressure differences (0.05 in. w.g. sprinklered); §8.4 acceptance testing (A.8.4.3 points to AABC, NEBB, TABB, ASHRAE and SMACNA procedures); §8.6 periodic testing (dedicated systems semiannually, nondedicated annually, on standby power where applicable). The 2021 change to door-open conditions is taken from the publisher’s change summary; we did not have the standard’s text.
4. NFPA 101, Life Safety Code, 2012 and 2024 editions: §7.2.1.4.5 door operating forces, §7.2.3.9 enclosure pressurization (0.05 in. w.g. sprinklered / 0.10 in. nonsprinklered, 30 lbf limit), §7.2.3.10 activation, §7.2.3.12 emergency power. The 2024 edition adds that pressurized enclosures follow NFPA 92 (§7.2.3.9.1.1).
5. NFPA 80, Standard for Fire Doors and Other Opening Protectives, 2013 edition, §4.8.4.1: ¾ in. maximum clearance under the bottom of a fire door.
6. Georgia Rule 120-3-3, State Minimum Fire Safety Standards (2020 edition of the rule): amendments to IFC §909 naming NFPA 92, ASHRAE/SFPE Design of Smoke Management Systems and ASHRAE Guideline 5 as accepted engineering references, and requiring smoke detectors at pressurization fan intakes. Confirm the wording in the rule currently in force.
7. CMS Life Safety Code survey, K-0771 Engineered Smoke Control Systems (NFPA 101-2012 §18.7.7 / §19.7.7) and K-0225 Stairways and Smokeproof Enclosures.
8. UL 864, Control Units and Accessories for Fire Alarm Systems; UUKL is UL’s product category for smoke-control system equipment.
9. J. H. Klote, J. A. Milke et al., Handbook of Smoke Control Engineering (ASHRAE/SFPE/ICC/NFPA), and the ASHRAE Handbook, HVAC Applications, smoke control chapter: door-opening-force equation, single versus multiple injection, stack effect.
10. AABC, NEBB and TABB: certification programs for air-balancing firms and technicians that perform smoke control testing.
11. AABC TAB Talk, “Mastering Stairwell Pressurization — A TAB-Centered Approach” (YouTube).
Open the discussion panel to comment, flag an inaccuracy, add field experience, or ask a question. Approved contributions earn SRP and may be incorporated into the article.