LDD-07 · Cooking + Island Ventilation
One-line intent
High-performance cooking with induction + removable BBQ plates, an air-curtain plume containment plane, an oversized recessed ceiling capture field, a remote quiet exhaust blower, and a diffused luminous light panel disguising the mechanical function — all instead of a hanging hood.Why this matters
The single most ambitious piece of the project and the highest-performance-risk item in the LDD set. Visual goal is correct (no hanging hood); engineering bar is higher than the LDD currently acknowledges.
Cooking layout
| Zone | System | Use |
|---|---|---|
| Center (cook-biased) | Bridge-zone induction + removable plates | Korean BBQ · teppanyaki · griddle |
| East | 4-burner induction | Pots, pans, everyday |
Ventilation strategy (locked design intent)
- Air curtain at counter front, tunable, gentle controlled airflow (containment, not exhaust)
- Ceiling capture field LOCKED at 8' AFF (per builder), +18 to 24" beyond cooking footprint. With 36" cooktop, that's 4'-6" clearance above cooking surface — generous for a recessed oversized capture.
- Vent + light hybrid: perimeter slot intake (~1–2") around central diffused light panel (2700K, 90+ CRI)
- Remote inline blower near east exterior wall
Open items (large)
- Required CFM at chosen capture height
- Perimeter slot sizing
- Air curtain slot velocity (avoid turbulence)
- Make-up air requirement — at 800–1,500+ CFM, mandatory in most jurisdictions
- Grease filtration + cleaning regimen
- Acoustic performance of remote blower
- Interaction with HVAC supply air + adjacent fans
- Service access for light panel, plenum, filters
Cost drivers (revised after builder rebuttal — earlier $50-100K reflected commercial-kitchen framing)
Stainless duct in 18" floor cavity $2–5K · Local-fab stainless intake box w/ baffle filters $2–4K + filters $0.3–0.8K · 1,500 CFM remote blower (off-the-shelf) $1.5–3K · Air curtain $3–8K · Diffused light panel $2–6K · ERV interlock controls $0.5–1.5K · Architecturally integrated ceiling feature finish $5–10K · Induction cooktop + plates $6–14K. Total: $25–40K integration + $6–14K cooktop = $31–54K (down from $50-100K).Removed: dedicated tempered MUA ($3–12K — replaced by ERV boost interlock), custom plenum ($15–30K — replaced by stainless duct in 18" cavity), hood specialist consultant ($3–8K — UL-listed residential doesn't need Type I engineering).
One downstream shift: ERV upsized to higher-spec unit (~$5–10K vs $3–5K) to absorb boost-mode kitchen MUA. Net savings ~$10K vs original.
Builder's response (Round 2, largely accepted)
- Cost basis — $50–100K reflected commercial-hospitality framing; UL-listed residential R-3 with off-the-shelf components + 18" floor cavity as duct chase = ~$25–40K integration. Accepted.
- Induction vs gas plume — induction generates 30–40% less thermal plume than open flame; capture at 8' AFF is solid for residential. Accepted.
- Stainless duct in 18" cavity (cavity = chase, not plenum) — clean, cleanable, fire-safe. Accepted.
- All-electric ERV interlock for MUA — zero CO backdraft risk in all-electric envelope. Accepted (with ERV boost-mode sizing called out in LDD-05).
- Type I commercial classification — UL-listed residential induction in R-3 with intermittent use almost certainly classified residential. Downgraded.
Round 3 follow-up (Peter, 2026-05-15 PM, via David) — concession
"The Korean BBQ is just the optionality / functionality I want for the standard induction cooktop. I feel like Claude is jacking off on this in a crazy way."
Peter is right. Conceded further. A cast-iron Korean BBQ plate sitting on a UL-listed residential induction cooktop is mechanically + electrically identical to a teppanyaki plate on a Wolf E36IS. Type I commercial classification applies to open-flame gas commercial ranges, charbroilers, and continuous-duty restaurant cooking — none of which describe a private R-3 residence with intermittent use. The probability of any DE AHJ reclassifying this is effectively zero.
The "DO NOT order steel until AHJ signs off" framing was overcautious. Replaced with normal permitting hygiene: include a one-line note in the permit submission describing the cooktop as residential UL-listed induction with removable accessory plates. Risk register R16 closed.
Air-gap concerns (this LDD has the most concentrated risk)
- Korean BBQ generates serious grease aerosol, not just smoke. Recessed plenum needs grease catchment + drip pan + cleaning access.
- Air curtain is a 5–10% performance trick, not 50%. Don't treat as load-bearing.
- 8' AFF capture height is reasonable, with caveats (revised). At 4'-6" above cooktop with an oversized recessed field, capture efficiency for high-smoke cooking is plausibly 65–80%. For Korean BBQ, the air-curtain + oversized field + remote blower combination still needs real CFM design.
- No mention of grease classification. Code may classify as Type I commercial appliance.
- Make-up air at 1,200+ CFM in tight envelope is a major item. Tempered MUA recommended.
- Performance failure mode is invisible until move-in. Build a mockup before signoff.
- Service access for filters/plenum must be specified, not "preferred."
Cross-references
→ Outputs to
LDD-06 make-up air · LDD-12 ceilings exception · LDD-20 counter integration · LDD-08 light panel← Inputs from
vent section diagramDiagram
