OVS-H1 : 2026 LIVING STANDARD EDITION 1.2
Outdoor cooking ventilation, held to a standard.
Indoor hood rules do not survive contact with wind. We study how smoke, heat, and grease actually behave above an open-air grill — then write it down as plain-language guidance a homeowner can act on, with the physics one click beneath every claim.
Ask about hood performance
Start with your question
Plain-language answers first. Each one traces to the research brief and instrument that back it.
What CFM does my outdoor kitchen hood need?
A 60,000 BTU gas grill at a 30-inch wall mount needs a minimum of 892 CFM under moderate wind exposure, served by a 1,200 CFM blower — 727 CFM sheltered, 1,004 CFM exposed with side panels, 1,394 CFM exposed without. An island mount multiplies the minimum by 1.20, to 1,070 CFM, because it loses the back wall's free confinement. The figure comes from the plume's mass flow at the hood — source strength and mounting height — not from hood width.
2.2Does wind really affect an outdoor range hood?
Yes — at a 48-inch island hood in a side wind, modeled capture drops from about 87% in still air to 51% at 5 mph and to roughly 8% at 10 mph. Wind is the single largest variable in outdoor hood performance, larger than CFM or hood size, because it moves the plume out from under the hood before the exhaust can act on it.
2.3Island or wall-mounted outdoor range hood — which works better?
It depends on where the wind comes from. With the wind blowing from behind the grill, a 48-inch wall hood holds about 88% modeled capture at 8 mph while an island hood over the same grill drops to about 12% — the wall shelters the plume and reflects it back into the capture zone. With the wind blowing across the hood face, the wall is parallel to the flow and the two mounts read the same.
2.4How far should an outdoor hood extend past the grill?
The plume's capture diameter over a medium gas grill is already about 27 inches at the cooking surface — wider than the 24-inch grate — and grows to about 41 inches by a 30-inch mounting height and 50 inches by 48 inches (RB-002). The hood has to overhang the grill on every side to stay ahead of that growth, and then by more on the side the wind pushes toward: the papers call for 11 to 26 inches per side depending on height.
2.5Do side panels actually help an outdoor hood?
Yes, substantially. On a 48-inch island hood in an 8 mph side wind, modeled capture rises from about 20% with no panels to about 70% with panels on both sides, because two panels reaching two-thirds of the way to the cooking surface cut the wind the plume feels to 40% of ambient (RB-009 Table 3.1a) — the single largest performance gain available from any post-installation change.
2.6How high should an outdoor range hood be above the grill?
Centerline plume velocity over a medium gas grill drops from about 412 fpm at 24 inches to 393 fpm at 30 and 377 fpm at 36 — the plume never runs out of velocity at any standard height. What height changes is how much plume the hood must swallow (550, 747 and 972 CFM at those three heights under moderate exposure), how wide the plume has grown, and how far wind can push it before capture.
2.7Can I use an indoor range hood outside?
Physically, yes — but its ratings won't come with it. Indoors a hood gets six free capture assists: walls, a ceiling, room negative pressure, controlled makeup air, still air, and a finite room volume that recirculates escaped smoke back to the hood. Outdoors all six are gone, first-pass capture is the only capture, and the indoor rules a spec sheet is built on run 1.7-2.5x too low for open-air conditions.
2.8What size outdoor range hood do I need for my grill?
The plume sets the width, not the grill. Over a medium gas grill the capture diameter is about 27 inches at the cooking surface and 41 inches by a 30-inch mounting height, before any wind; the papers apply a 1.38 margin for turbulence and puffing and recommend a 57-inch hood (RB-002). A hood sized by the familiar '+6 inches per side' retail rule only just covers the still-air plume; the papers' outdoor tables run wider — on the order of twice the cooking surface width for reliable open-air capture.
2.9Does an outdoor range hood need a duct?
It depends on what stands between the hood outlet and open sky. Outdoors the atmosphere is the destination — open-air dilution disperses exhaust within a few meters — so a fully open installation can discharge directly at the hood, and a recirculating ('ductless') hood has no enclosed room to clean and no way to hold back combustion gases. Under a roof, the exhaust needs a duct out of the covered volume, or the hood collects smoke at grill level only to release it at ceiling level.
Instruments
Live, explorable models. Every assumption is a control you can move; every output cites its parent brief.
Capture Demonstrator
Interactive plume-capture model for an outdoor range hood: mounting height, … I-02Outdoor Range Hood CFM Calculator
Physics-based calculator for the exhaust airflow (CFM) an outdoor range hood … I-03Plume Width by Height
How the plume capture diameter grows from cooking surface to hood height for … I-04Wind Deflection Trajectories
Side-view diagram of how crosswind bends the buoyant cooking plume at each … I-05Hood Geometry Comparison
Side-by-side capture comparison of hood widths and mount types over the same … I-06Velocity Decay Curves
Centerline velocity decay of the cooking plume from the cooking surface to … I-07Side Panel Effectiveness
Capture with and without side panels across the wind range: on a 48-inch … I-08Indoor vs. Outdoor Ventilation Comparison
Why indoor ventilation assumptions fail outdoors: wall confinement, … I-09Heat Release Rate Comparison
Total and convective heat release for the eight RB-001 reference cooking … I-10Grease Aerosol Deposition Pattern
How droplet size sets where escaped grease aerosol lands: Stokes settling … I-11Failure Mode Taxonomy
Reference card classifying the six failure modes of outdoor BBQ hood …Every instrument is being rebuilt as a live visualization on the model of Figure 1. Each embeds the equations of its parent brief and exposes every assumption as a control — nothing is hard-coded that you cannot see and move.
Research library
Twelve briefs in four tiers. Foundation establishes the physics; Frontier marks where the evidence runs out.
| Designation | Title | Tier | Updated |
|---|---|---|---|
| RB-001 | Buoyant Plume Behavior from Barbecue and High-Heat Cooking Sources | FOUNDATION | 2026-09-29 |
| RB-002 | Entrainment and Lateral Plume Spread in Open-Air Environments | FOUNDATION | 2026-09-29 |
| RB-003 | Velocity Decay and Near-Field vs. Far-Field Capture | FOUNDATION | 2026-09-29 |
| RB-004 | Why Indoor Ventilation Assumptions Fail Outdoors | CORE | 2026-09-29 |
| RB-005 | Impact of Hood Geometry on Capture Performance | CORE | 2026-07-11 |
| RB-006 | Wind Interaction and Cross-Flow Effects | CORE | 2026-09-29 |
| RB-007 | Failure Modes of Outdoor BBQ Hoods | APPLIED | 2026-09-26 |
| RB-008 | CFM Requirements for Outdoor Cooking Ventilation | APPLIED | 2026-09-29 |
| RB-009 | Side Panel and Wind Baffle Effectiveness | APPLIED | 2026-09-26 |
| RB-010 | Gaps in Existing Standards, Codes, and Consumer Guidance | FRONTIER | 2026-07-11 |
| RB-011 | Grease Aerosol Transport and Deposition in Open Environments | FRONTIER | 2026-09-29 |
| RB-012 | Thermal Radiation and Plume Interaction at Hood Surfaces | FRONTIER | 2026-09-29 |
FOUNDATION — first principles, read these first CORE — the capture problem in full APPLIED — decisions and mitigations FRONTIER — active work, open for comment
Basis for trust
A standard is only as good as its process. Ours is written down, versioned, and open to challenge.
Methodology
Every quantitative claim traces to a derivation from published fluid dynamics or a cited measurement. Simplifications are declared where they are made.
Read the methodology →Governance
Versioned like a standard: numbered clauses, a published change log, an errata process, and open comment periods on every Frontier-tier brief before it advances.
Governance & change log →References
No manufacturer funding. No affiliate links. No sponsored placement. Every source cited is traceable to a published reference.
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