BBQ exhaust purifier maintenance SOP - cell washing, the pressure-differential log, and inspection response for the one machine that can shut the shop down

You are the equipment maintenance consultant for a BBQ restaurant. I am the technician. Write "exhaust purifier maintenance and inspection response" as an archivable SOP. Intervals set by local requirements and this shop's grease load stay at [ ] - not yours to fill, and no statute language or numbers may be quoted.

Open the SOP with the machine's standing: a dead grill is a revenue problem; a dead purifier is an existence problem - smoke complaints are the shortest path from BBQ shop to closure. Design the whole document at that severity.

The SOP covers:

1. One file per unit: model, airflow, install date, wash cycle [days], wash method (in-house / contracted) - each unit gets its own file
2. Daily (at close, within five minutes): wipe the hood surface, empty the grease cup, clear carbon buildup around the burners
3. Periodic cell wash:
   - Power off, wait [minutes] for discharge before removing the collection cells - the cells hold residual charge; this is a safety red line with no "we're slammed tonight" exemption
   - Removal and reinstallation order; detergent concentration and soak time per [ ]; rinse, dry fully, reinstall
   - After reinstallation, power up and read the pressure differential; log it beside the pre-wash reading
4. The pressure-differential log (the core deliverable):
   - One reading before and one after every wash, sequenced by date into a trend
   - Double duty: internally - once the differential climbs back to [trigger], pull the next wash forward; the reading beats the calendar (winter and summer grease loads differ). Externally - the log is the proof of washing on cycle
5. Fan and ductwork: schedule quarterly clearing [ ] driven by the differential trend and the log's grease record, not by the calendar
6. Inspection and complaint response (its own section):
   - When an inspector comes, produce: the wash log, the differential records, (if contracted) the contract and invoices
   - Neighbor smoke complaints follow this order: purifier differential reading -> duct leaks -> hood capture efficiency -> exhaust outlet direction and wind - ascending by investigation cost, no skipping steps
   - On the spot: measure the differential and preserve the reading first, talk second
7. Escalate to outside repair: differential abnormal but not falling back after a wash, fan noise with falling throughput - stop here and call the contractor; no self-service teardown of the main unit

Three red lines:
- Removing cells without power-off and discharge - personal safety, zero exception clauses
- Backfilling the log - an entry missed that day is missed; writing "missed same-day, this note added on [date]" is fine, fabricating the same-day number is not. A backfilled log reads worse than none at inspection (a batch of same-ink entries with sequential timestamps cannot hide)
- A crash wash right before an inspection - the log's timestamps will expose it, and the crash itself confesses that the cycle was never kept

Constraints:
- No statute text or numbers - the cycle [days] comes from local requirements and this shop's grease load; where the two disagree, take the stricter
- No "keep the equipment clean" uncheckables - every action lands on a time, a reading, or a document
- Two pages maximum; the "inspection and complaint response" section must survive being torn out and taped up in the office

Why it is written this way

Opening with the machine's standing sets the document's entire temperament. "The purifier is an existence problem" is not rhetoric - a dead grill costs a night's revenue; a failed purifier that meets one complaint or one inspection wagers the shop's license to be open. Writing that severity into the opening is what holds up the safety red lines, the logging discipline, and the inspection-response section after it; without it, the document gets filed as generic equipment maintenance and is the first thing sacrificed on a busy night.

The pressure-differential log is the SOP's real deliverable - the binding of "we washed it" to "we can prove we washed it." Plenty of shops genuinely wash the purifier and keep no record, which at inspection counts as never having washed it; the log turns each wash into a presentable event (date, before-and-after readings). The internal half is just as practical: grease accumulation moves with season and volume, and a calendar cycle fixed in stone either washes early (money wasted) or late (efficiency gone) - the differential trend is more honest than the calendar. One indicator serving both the shop's own decisions and outside proof is why it is named the core deliverable.

The smoke-complaint ladder ascending by cost exists because that is where shops wander longest. A complaint lands and most shops first blame the exhaust direction or a sensitive neighbor - a week of engineering at minimum - while the most common causes (loaded cells, a leaking duct seam) are confirmed or eliminated by one differential reading and one visual. The order is fixed and no-skipping because a jumping investigation burns a week on wind direction and ends with the discovery that the cells went three months unwashed.

The second red line punishes backfilling rather than missing, and the calibration matters: a missed entry is a mistake, and an honestly annotated gap is a credibility plus (a record with a confessed hole beats a flawless one); a backfill is fabrication - dozens of same-ink pages written in one sitting cannot hide their timestamps, and when they are caught, what's forfeited is not those pages but the entire record's standing. An inspector's logic is short: one fabrication, everything suspect.

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