Vendor Teardown 04 — Air Circulation

Source: 05_air_circulation.jpeg + 07_pricing_offer.pdf

Read (equipment spec)

RoomEquipmentQty
FloweringWall fans4 / room
FloweringUnder-table fans3 / room
VegetativeFans2 + 2
MothersFans3 + 2

Pricing offer breakdown

RoomTypeQtyUnit €Line €
Flowering 1Wall fan479316
Flowering 1Multi fan (under table)379237
Flowering 2Wall fan479316
Flowering 2Multi fan (under table)379237
VegetativeWall fan279158
VegetativeMulti fan (under table)279158
MothersWall fan379237
MothersMulti fan279158
Total€ 1 501

Pricing resolves the cryptic "2 + 2" / "3 + 2" notation — it's wall fans + under-table "Multi fans", confirming my inference.

Findings

Finding 1 — 7 fans per flowering room is appropriate density

4 wall + 3 under-table = 7 fans over 24 m² ≈ 3.4 m² per fan. Commercial rule of thumb is 3–5 m² per oscillating canopy fan. Density is correct. The wall/under-table split is the modern double-stack pattern that breaks up the stagnant cool/humid microclimate at floor level where botrytis and powdery mildew start.

Finding 2 — €79 per fan is generic

€79 for a "wall fan" or "multi fan" suggests a basic oscillating or clip-on model (Secret Jardin Monkey Fan tier, or any generic Chinese brushless 8" model). Nothing commercial-grade like the €150+ Cloudline / AC Infinity products that run continuously for 5+ years without bearing wear.

At 7 fans × 2 flowering rooms × 24/7 operation, bearing life is the limiting factor. Budget €50–100 per fan replacement per year as opex on top of the capex. Over 3 years that's ~€450 maintenance on €553 of initial hardware.

Finding 3 — No exhaust / extraction fans anywhere

The air circulation spec is all recirculating, no exhaust. This implies:

Gap: no inline duct fans + carbon filters anywhere in the €82 584 offer. For a commercial facility this is a €2 000–4 000 hole (6 × 315 mm carbon filters + 6 × AC Infinity / Dayton inline fans, one scrubber per flowering + veg + mothers + dry).

Finding 4 — No airflow CFM target specified

The vendor specs count of fans, not their CFM rating. For a sealed 24 m² × ~3 m high flowering room (~72 m³ volume), best practice is 10–20 air changes per hour for internal circulation, i.e., 720–1 440 m³/h of mixed airflow. 7 fans at ~200 m³/h each ≈ 1 400 m³/h — at the top end. Adequate if the fans are actually 200 m³/h each, which at €79 they probably are.

Confirmations still needed from vendor

  1. Fan brand / model / CFM / noise rating / expected life.
  2. Is there any exhaust / carbon filtration in the €82 584 total, or is it assumed separate?
  3. If sealed, how is positive / negative room pressure managed (for airlock compliance)?
  4. Where is replacement stock sourced once fans fail?