DIY Proposal 05 — Missing From Vendor (CO₂ + Carbon + Security + Backup + Mech)

Source: vendor_teardown/09_pricing_and_gaps.md §"What's missing" and RED FLAGS 6, 7, 8, 9.

These line items are not in the vendor's €82 584 but the customer will need them within weeks of install. Including them here makes the DIY counter-proposal a fair apples-to-apples comparison, not a hidden-scope shell game.

Any fair cost comparison has to add these to both sides — the vendor build needs them just as much as the DIY build, but the vendor didn't quote them so the customer doesn't see the line items until the first neighbour complaint / first grid outage / first licensing inspection.

1. CO₂ enrichment hardware (~€1 610)

Why: Lighting intensity at 593 W/m² top-only is only productive above 1 000 ppm CO₂. At ambient ~420 ppm the extra photons above ~800 W/m² PPFD become heat. This is the basic math of commercial LED cultivation.

Vendor billed Growlink Climalink with CO₂ controllers (€499 × 5 rooms) but no CO₂ hardware.

Safety critical: every CO₂-dosed room must have a hardwired CO₂ alarm → contactor cutoff independent of HA. If HA hangs with the solenoid open, PPM climbs to 4 000+ ppm in 30 min, and a worker entering the room without checking the alarm panel loses consciousness. The €160 for standalone alarms is not optional.

2. Carbon filtration / odour control (~€2 640)

Why: Cannabis at late flower is extremely pungent. Malta's cannabis production licensing requires scrubbed exhaust, and neighbours will complain within days of the first flower cycle regardless of licensing.

Vendor has no exhaust fans, no inline fans, no carbon filters anywhere in the €82 584. This is hidden scope the customer will buy on day 1.

AC Infinity + Phresh is the grow-room standard. Cheaper Chinese carbon filters work but saturate after 3–4 months in continuous 60 % RH. Phresh filters are the known-good choice — saturate after ~12 months in flower rooms.

The customer can reduce this line by using Chinese filter equivalents from AliExpress for about 50 % less, but the replacement frequency doubles → total 3-year cost is identical. Go Phresh.

3. Backup power (~€3 200 minimum, €7 500 for a proper solution)

Why: Malta grid has routine ~30–60 minute summer outages. A 4-hour outage in week 5 of flowering = irreversible crop damage (temperature rise + CO₂ disappearing + irrigation stopped). At the facility's ~50 kW peak load, a true full-backup genset is expensive; the realistic compromise is targeted backup for the critical loads.

Tier 1 — minimum viable (€3 200)

Covers HA host, Zigbee hub, climate controls, irrigation dosing, a few key sensors. Does NOT keep the lights or HVAC running — but keeps the brain alive so it can gracefully shut down lights/dehu and monitor temp rise.

Tier 2 — proper gen-set (€7 500)

Covers lighting + HVAC + everything for 4–8 hours depending on tank. Diesel, automatic transfer, weather enclosure.

Recommendation: Tier 1 for DIY counter-proposal. The Ecoflow + graceful-shutdown gives you 30–60 min of alert-and-react time which handles 95 % of real-world Malta outages. Tier 2 is over-engineered for a small facility unless the crop value per cycle exceeds €50 k.

4. Security + access control (~€2 400)

Why: Malta cannabis production licensing explicitly requires physical security, tamper-evident packaging, and visitor logs. Non-compliance = licence at risk.

Integrates with HA via the onvif and Reolink integrations — cameras trigger automations (alert on motion during off-hours, lock-down room if door opened during CO₂ dosing).

Visitor log is a separate thing — HA can trigger logging on door events, but for licensing compliance the customer probably wants a dedicated visitor management tool (QR code sign-in, paper log is also acceptable).

5. Mechanical room / condenser location (~€1 000 for rework, or €0 if feasible)

Vendor floor plan has no mechanical room drawn. The 18 condensers from the DIY split AC approach (12 for flowering + 6 for other rooms) need outdoor placement. Options:

1. Rooftop (most likely) — ~€500 for brackets, penetrations, cable runs, and weatherproofing. Requires roof access and builder's consent.
2. Yard / external wall — ~€300 for brackets and cable runs. Requires yard space, no neighbours on the condenser wall.
3. Dedicated mech room inside building footprint — biggest cost change, requires re-architecture of the floor plan, ~€2 000–4 000 for builder works.

Assumption: rooftop placement is available. Budget €1 000 all-in for brackets, penetrations, and cable runs.

Summary — "missing from vendor" additions

These €10 840 must be added to BOTH the vendor build and the DIY build for a fair comparison. The vendor just didn't quote them; the DIY proposal is explicit about them.

See ../comparison/cost_comparison.md for how this folds into the headline number.