Side Panel Effectiveness

This diagram shows the improvement in capture performance when side panels are added to an outdoor hood installation. Panels are the single most effective post-installation intervention for wind-exposed sites.

Reference readings

Representative values below are computed directly from the same capture-fraction and panel-sheltering modules (physics/capture.mjs, physics/sidepanels.mjs) driving the instrument above — a 48-inch island hood over a medium gas grill at a 30-inch rise, wind across the hood face, two side panels of fractional enclosure f = 0.67 (panel depth two-thirds of the mounting height); live values update as you move the wind and panel controls. The table is regenerated by scripts/generate-reference-tables.mjs, never typed by hand.

On a 48-inch island hood in an 8 mph side wind, this model’s capture rises from about 20% with no side panels to about 70% with panels on both sides — a configuration you can toggle to in the instrument above, which starts with no panels. Two side panels at f = 0.67 carry a lateral wind-reduction coefficient R_panel = 0.60 in RB-009 Table 3.1a, so the plume feels 40% of the ambient speed — 3.2 mph instead of 8 [RB-009 §3.1]. Less effective wind means less deflection at every height the plume rises through, which is why the gap between the two columns widens as wind speed increases (from 0 points in still air to 50 points at 8 mph) rather than narrowing. Even at 16 mph — well above the “Exposed” class — the panel-equipped hood in this model still holds about 35% capture while the unshielded hood has collapsed to about 0%; RB-006 counts any open-air capture at that speed as impractical [RB-006 §3.8, §3.10].

Key Findings

Side panels reduce effective wind speed by 45–85% against a lateral wind, depending on depth. RB-009 Table 3.1a gives R_panel = 0.45 at half the mounting height, 0.60 at two-thirds, and 0.85 for full-depth panels; against a front or rear wind two side panels do far less (R_panel = 0.12–0.22) [RB-009 §3.1]. Panels move many Exposed installations back into the Moderate wind class [RB-009 §3.6].

Required CFM drops 28%. The K_CFM multiplier decreases from 5.75 (exposed, no panels) to 4.14 (exposed, with panels) — a 28% reduction in required exhaust for the same hood [RB-008 §2.2]. The CFM tables in RB-008 §3.2 carry the per-source figures.

Capture recovers 15–20 points at 5 mph and more in stronger wind. RB-006 Table 3.10 puts a 57-inch hood over this grill at 70–75% capture in a 5 mph wind and 88–92% with full side panels [RB-006 §3.10]; the model reads 72% and 93% for that hood, and 51% versus 80% for the 48-inch preset.

Minimum panel depth: 50% of mounting height. Panels extending at least half the distance from hood to cooking surface provide meaningful wind reduction; at 75% depth, diminishing returns begin [RB-009 §3.4].

A single panel is not modeled. RB-009 warns that a lone windward panel creates a recirculation zone that can carry plume gas out the open side [RB-009 §3.5]; no paper tabulates its effect, so the instrument offers none or both.

Panel Configurations

• Two side panels (island): Effective against lateral crosswind; minimal protection from front/rear wind [RB-009 Table 3.1a]
• Three panels (sides + rear): Most complete protection; blocks 3 of 4 directions [RB-009 Table 3.1b]
• Three panels with wall (sides + wall-mount): Most effective; the wall provides the rear barrier plus its recirculation-zone shelter [RB-006 §3.9.2]

Source Papers

• RB-009: Side Panel and Wind Baffle Effectiveness — Wind reduction coefficients (§3.1), panel depth (§3.4), single-panel caution (§3.5)
• RB-006: Wind Interaction and Crossflow — Wind classification (§3.8), combined mitigation (§3.10)