A BIBO housing arrives at the factory inspection stage already built to a configuration that was negotiated and approved earlier. The question for the buyer is not whether it looks correct, but whether the acceptance process actually proves what each stage is capable of proving — and whether anyone confirmed that before signing off. Confusing what a factory can demonstrate with what only the installed site can demonstrate is where acceptance records lose their value as qualification evidence.
Divide factory and site acceptance by what each location can prove
| Acceptance stage | What to verify at this stage | Limite delle prove |
|---|---|---|
| Factory acceptance test (FAT) | Approved design, fabrication details, component identification, access, controls, ports, and agreed functional checks that can be completed at the supplier | Does not establish installed duct orientation, utilities, dampers, monitoring points, service clearance, or site control integration |
| Site acceptance test (SAT) | Installed duct orientation, utilities, dampers, monitoring points, service clearance, and site control integration | Does not replace separate factory filter evidence or the protocol-defined installed leak test record |
A alloggiamento "bag-in bag-out" is tested in two physically distinct environments, and each one has a hard limit on what it can show. At the factory, the supplier can confirm that the unit was built to the approved design: the shell construction, the filter housing arrangement, the bag-change mechanism, the identification of installed components, and the functional behavior of items that do not depend on how the unit will eventually be ducted or powered on site. This is meaningful evidence, but it is evidence about the equipment as a standalone object.
What the factory cannot confirm is anything that only exists once the housing is installed into its final position. Duct orientation relative to the room layout, the utility connections that will actually supply the unit, the way dampers behave once tied into the site’s control logic, and the clearance available for service access are all conditions created by the installation, not by the manufacturing process. A factory test can simulate some of these conditions, but simulation is not installation. Where a buyer treats a clean factory acceptance record as proof that the unit will interface correctly on site, that assumption carries risk the record was never designed to cover.
This separation matters most when scheduling pressure pushes a project toward collapsing the two stages into one combined “final” sign-off. If the site conditions were not final at the time of the factory test, or if the factory test stood in for checks that depend on installed configuration, the resulting paperwork can look complete while leaving real interface risk unexamined. The buyer’s task at this stage is not just to collect two sets of signatures but to ask, for each item on the acceptance list, which location was actually capable of verifying it. If a check depends on the installed duct run, the installed utility supply, or the installed control integration, a factory record cannot answer it regardless of how the test was described.
Trace housing features and documents back to the approved URS
Every item checked during acceptance should map back to a specific requirement in the approved user requirement specification. This traceability is what turns an acceptance test from a general inspection into a targeted verification exercise. If the URS specified a particular access configuration, bag-change method, damper arrangement, or control interface, the acceptance protocol should reference that requirement directly rather than relying on a generic checklist that happens to resemble it.
The practical reason this matters is that BIBO housings are project-configured equipment. The same product family can be built with different port locations, different damper counts, different control philosophies, and different service-access arrangements depending on what the project required. An acceptance checklist written for a different configuration, or for a generic version of the equipment, will not catch a mismatch between what was approved and what was actually built or installed. The housing can pass every item on such a checklist and still fail to match the URS in a way that only becomes visible later.
Where the URS changed during the project — through a design review, a change request, or a site condition discovered after the original specification was written — the acceptance protocol needs to reflect the current, approved version of the requirement rather than the original one. A buyer reviewing acceptance documentation should confirm which version of the URS the protocol was written against and whether any intervening change requests were incorporated before the test was run. An acceptance record that traces cleanly to an outdated requirement does not establish that the installed housing meets the current one.
This tracing exercise also clarifies what the supplier and the installer are each responsible for proving. Design and fabrication details trace back to the design-stage requirements the supplier approved. Installed interface requirements trace back to whatever the site engineering package specified. Keeping that distinction visible prevents a single signature from being read as covering both halves of the requirement set.
Witness access, controls, dampers, ports, and agreed factory checks
The physical items a buyer or their representative witnesses at the factory share a common feature: they can be checked without needing the final installation context. Access panels, control enclosures, damper assemblies, and the ports used for later filter testing can all be opened, operated, and inspected on the shop floor because their function at this stage does not depend on duct orientation or site utilities.
Witnessing access means confirming that doors, panels, or bag-change ports open and seal as designed, and that the mechanism used to isolate the filter during a change behaves as specified without depending on anything installed later. Witnessing controls at this stage means confirming that the control elements present on the unit — indicators, interlocks, or local operating controls — respond correctly when exercised under factory power, understanding that their behavior once integrated into a site control system is a separate question addressed later. Witnessing dampers at the factory confirms that the damper opens, closes, and indicates position correctly as a standalone component; it does not confirm how that damper will behave once tied into the site’s pressure control strategy, because that behavior depends on the installed ductwork and control loop.
Ports deserve particular attention because they serve a specific downstream purpose: they are where aerosol challenge testing and scan access will occur once the housing is in service. Confirming port location, accessibility, and condition at the factory stage is useful precisely because any defect found there is far easier to correct before shipment than after installation. A port that is difficult to access once the unit is placed in its final position was difficult to access the day it left the factory; the factory stage is the opportunity to catch that condition while it can still be changed.
The agreed functional checks completed at this stage are whatever the approved protocol specifies as achievable without installation. A buyer should confirm, before witnessing, exactly which checks fall into this category and which have been deliberately deferred to site — so that what gets witnessed matches what the protocol intended, rather than drifting toward whatever is easiest to demonstrate that day.
Confirm installed interfaces, monitoring points, clearance, and integration
Once the housing is installed, a different set of conditions becomes checkable for the first time, and these are the items that site acceptance exists to confirm. Duct orientation is one: a housing built to a correct internal configuration can still be installed with ductwork oriented in a way that affects airflow distribution or access, and this is only visible once the connection is physically made. Utility connections are another — power, and any other service the unit depends on, must be confirmed as connected correctly and supplying the conditions the unit was designed around, which a factory test using temporary or simulated supply cannot fully replicate.
Dampers, checked as standalone components at the factory, now need to be confirmed as part of the site’s control integration. This means verifying that the damper responds correctly to the actual control signals it will receive in operation, not a simulated signal used for a factory functional check. Monitoring points — wherever the project specifies continuous or periodic monitoring of the housing’s performance — need to be confirmed as correctly located, correctly connected to whatever monitoring or building management system the project uses, and giving readings consistent with the conditions actually present at that installed location.
Service clearance is a site-specific condition that cannot be fully verified until the unit sits in its final position relative to walls, structural elements, and other equipment. A clearance dimension that was acceptable in a layout drawing can be compromised by as-built conditions that differ from the drawing, and the only way to confirm adequate clearance for future filter changes or maintenance access is to check it after installation, in the actual space.
Where any of these installed conditions differ from what the design assumed, the buyer needs a mechanism for raising and resolving that difference before treating site acceptance as complete — because an unresolved mismatch between the as-built condition and the design intent is exactly the kind of gap that later qualification testing may not catch if it is not looking for it specifically.
Close deviations and integrity-test records before acceptance
| Categoria di prova | What must be clear before acceptance | Confine decisionale |
|---|---|---|
| FAT or SAT deviation | Closure against the approved URS and approved protocol | Do not treat FAT or SAT completion as qualification evidence while deviations remain open |
| Factory filter evidence | A separate record from installed leak testing | Factory evidence does not replace the installed leak test |
| Installed leak test | Method, instruments, conditions, acceptance criteria, and records identified by the protocol | The cited filter-testing scope does not supply equipment-specific limits; the approved protocol must define them |
| Documentazione comprovante i requisiti | Installation, challenge testing, and intended operating conditions addressed through the applicable IQ, OQ, and PQ evidence | FAT and SAT records form part of the evidence package but do not alone establish qualification |
A BIBO housing acceptance package is not complete because every scheduled test ran; it is complete because every deviation raised during those tests has been closed against the approved URS and the approved protocol, and because the records that remain open after closure clearly show what was verified, by what method, and against what criteria. Treating a finished test schedule as equivalent to a resolved acceptance record skips the step where open deviations get assessed, dispositioned, and either corrected or formally accepted with justification.
Filter-related evidence generated at the factory needs to be kept as a distinct record from the leak testing performed after installation. These are not interchangeable: factory filter evidence confirms something about the filter and its seating under factory conditions, while an installed leak test — referenced in standards such as IEST-RP-CC034 for HEPA and ULPA filter leak testing — confirms performance once the filter is in its final installed position, under the airflow and environmental conditions that position creates. The protocol governing the installed test needs to specify the method, the instruments used, the conditions under which the test was run, the acceptance criteria applied, and the records generated, because the cited standard provides scope for how such testing is structured rather than equipment-specific limits — those limits come from the approved project protocol, not from the standard itself.
Qualification evidence sits above both acceptance stages. Guidance such as EudraLex, volume 4, allegato 15 describes vendor and site acceptance activities as inputs that, together with installation, challenge testing, and evidence collected under intended operating conditions, build toward installation, operational, and performance qualification. FAT and SAT records contribute to that evidence package; they do not substitute for it. A buyer preparing for a project conversation should know which qualification stage each piece of acceptance documentation is meant to feed, so that a request for configuration details or a quotation review correctly identifies what evidence already exists and what the project still needs to generate.
Domande frequenti
Q: How should a buyer decide whether a BIBO housing check belongs in FAT or SAT?
A: Assign the check to FAT when it can be proven on the approved housing at the supplier, and to SAT when it depends on the installed system or site conditions. Record that boundary in the approved protocol so each check has a clear location, witness point, and expected record.
Q: What should be ready before the BIBO housing FAT begins?
A: Have the approved URS and FAT protocol available, with the housing design, fabrication details, component identification, access, controls, dampers, ports, and agreed functional checks mapped to specific verification steps. The protocol should also define how observations and deviations will be recorded and closed.
Q: Does factory filter evidence eliminate the need for an installed leak test?
A: No. Keep factory filter evidence as a separate record and perform the installed leak test under its approved protocol. That protocol should identify the method, instruments, test conditions, acceptance criteria, and required records rather than relying on a general testing reference for equipment-specific limits.
Q: Can FAT or SAT be used as qualification evidence while deviations remain open?
A: Do not treat the completed test as qualification evidence until its deviations are closed against the approved URS and protocol. Each closure should show what was corrected or accepted and which requirement and test record support that decision.
Q: Are completed FAT and SAT records enough to qualify the installed BIBO housing?
A: FAT and SAT records contribute to the evidence package but do not establish qualification by themselves. Confirm that the applicable IQ, OQ, and PQ evidence also addresses installation, challenge testing, and intended operating conditions before closing the qualification package.
