How do I measure an enclosure to choose the correct rectangular pan dimensions?

Measure the interior opening along both length and width rather than the exterior footprint of the enclosure. Subtract three to four inches of clearance on every side so the burner has combustion air room and the flame stays clear of the interior walls. Gas fittings and ignition hardware occupy additional space inside the cavity, so confirm those clearances before ordering.

What is the difference between center fed and end fed rectangular manifolds?

A center fed manifold introduces gas at the midpoint and splits flow in both directions, halving the distance fuel travels to the furthest port. An end fed design sends gas the full length of the manifold, which works acceptably on shorter runs. On longer manifolds, end feeding commonly produces strong flame near the inlet and noticeably weaker flame at the opposite end.

How do I prevent water accumulation inside longitudinal burner ports?

Specify a manifold with a raised internal feed hub, which keeps the gas path above the level where water settles. Pair it with a pan carrying drilled weep holes to drain water away from the assembly rather than letting it pool. Long manifolds rarely sit perfectly level once an enclosure settles, so drainage matters more here than on a compact burner.

How much media should cover a rectangular burner?

Roughly one to two inches above the ports, applied evenly across the full length. Uneven depth along a long tray produces visibly different flame heights from one end to the other, which is often mistaken for a gas supply problem. Checking depth at several points along the manifold rather than at one spot prevents that.

Can a rectangular burner run on liquid propane?

Yes, with an inline brass air mixer valve installed at the burner inlet. Propane carries higher energy density than natural gas and needs additional ambient oxygen introduced before the fuel reaches the ports. Without that mixer, an elongated propane manifold produces soot across the media and a dark yellow flame along its full length.

Rectangle Burners

A rectangle fire pit burner runs the full length of a dining table or a masonry trench. Nobody at the far end sits beside a dark stretch of glass. Browse our catalog to compare manifold widths and feed configurations.

Center Feed Balancing and Elongated Layout Guide

Length is what makes the shape of the rectangle fire pit burner useful and what makes it difficult. Gas entering at one point has to arrive at both ends with enough pressure to light the same way. Delivering an even, full-length flame across a wide rectangular vessel requires careful planning around fuel feed entry points, port patterns, and supply line pressure.

Center Feed or End Feed: Which Should You Specify?

Feed position determines how evenly a long manifold lights. Gas naturally follows the path of least resistance, so fuel pressure drops as it travels further down the manifold.

A center feed design splits the run in two, halving the distance gas travels to reach the furthest ports on either side. An end feed configuration sends fuel down the entire length of the burner. End feeds work fine on shorter manifolds under three or four feet, but they struggle on longer runs. The classic symptom of specifying the wrong feed position is a strong, tall flame near the gas inlet and a weak, flickering flame at the far end. Once a rectangular manifold exceeds roughly four feet in length, choosing a center feed entry stops being optional on standard residential gas supply lines.

Why Are the Ports Staggered Rather Than Aligned?

Port drilling geometry dictates how the fire fills the pan. Staggered port drilling spreads flame across the full width of the manifold instead of producing a single narrow ribbon of fire. That single thin line is what linear burners track produces on purpose for sleek, narrow troughs.

On a wide rectangular tray, that port arrangement decides whether the fire reads as a lush, continuous body of flame or an awkward row of individual jets. Precision machine drilling also burrs and deburrs every port cleanly. This eliminates the high-pitched whistling noise that rough or punched holes create when turbulent gas flows through them under load.

How Do You Calculate Load From Length by Width?

Total heat output scales with total linear port inches across both axes, and elongated rectangular manifolds accumulate that port area quickly. To size a burner correctly, measure the interior opening of your enclosure on both axes and subtract three to four inches of perimeter clearance per side.

Work directly from that interior footprint rather than the exterior masonry dimensions, exactly as you would when sizing round burners to a circular pan. That perimeter gap provides crucial combustion air to keep the flame burning clean without starving or scorching the sidewalls. Finally, verify that your fuel supply maintains a steady working pressure of 7 inches of water column for natural gas or 11 inches of water column for liquid propane under full load.

What Happens to Water in a Long Manifold?

Water always collects at the lowest point inside the manifold, wherever that turns out to be. A steel burner manifold spanning several feet is rarely perfectly level once a hardscape enclosure settles over time.

Rainwater filtering through the fire glass or lava rock pools at the lower end of the manifold, corroding the interior gas path from the inside out. Trapped water also causes sharp popping sounds and uneven ignition when the gas turns on. Combining pre-drilled pan weep holes with a raised internal feed hub creates a gravity drainage system that keeps standing water completely out of your gas supply lines.

How Does Ventilation Work in an Elongated Enclosure?

An elongated enclosure cavity requires cross ventilation distributed along its full length, not just clustered at the extreme ends. Standard safety codes generally require 18 to 24 square inches of open vent area split across two opposing side walls.

For long trench or rectangular builds, spread those vent openings along the length of the structure rather than bunching them together at one end to ensure complete cross-draft airflow. Vent placement height depends on your fuel type. Liquid propane is heavier than air and collects at the bottom of the cavity, requiring low vents. Natural gas is lighter than air and rises to the top, requiring vents placed near the upper rim.

Which Geometry Suits Your Enclosure Better?

Burner shape should always follow the physical geometry of the opening you actually have:

Circular Openings: Round openings call for a ring burner, where guests sit equidistant from the central flame.
Square Enclosures: Square Burners fill four-sided enclosures cleanly from corner to corner.
Commercial Applications: HPC Fire Burners supply certified, pre-assembled commercial components built for heavy public use.
High-Efficiency Jet Burners: Precision brass venturi jet designs produce taller, fuller flames on measurably less gas consumption than standard drilled manifolds.

What Ignition Pairs Well With a Long Manifold?

Manual reach becomes the primary deciding factor when choosing an ignition system for a rectangular fire feature. Lighting a five or six-foot manifold by hand requires leaning over and reaching across the full width of a hot burner tray with a lighter. That physical safety hazard pushes most buyers toward push-button spark or automated electronic ignition on any burner beyond a modest length.

Whichever ignition architecture you choose, our custom build kits range covers everything from individual components to non-standard enclosure sizing, and high-output crossfire burners pair exceptionally well with automated electronic controls.

What Keeps a Long Manifold From Warping?

Preventing metal warpage requires reinforced internal framing along the entire span of the manifold. Intense heat cycling works on an unsupported length of steel much harder than on a compact circular ring. A thin-walled rectangular manifold will expand, bow downward at its midpoint, and warp out of shape within just a few seasons.

Heavy-duty 304 stainless steel construction with internal cross-bracing holds its structural geometry through years of extreme heat. Maintaining a flat manifold is essential because a warped burner changes port heights relative to the media bed, causing uneven gas flow and erratic flame height across the tray.

Upgrade Your Patio with a Precision-Engineered Burner

A long fire feature usually anchors an outdoor dining table or a patio wall run where people sit along the flame rather than gathered around a central point. That linear seating layout makes proper gas pressure, feed entry position, and port distribution essential to getting equal flame height from end to end. Send our technical specialists your interior opening dimensions, fuel type, and gas line size. We will confirm your feed position, port layout, and total BTU demand before anything ships to your job site.

Frequently Asked Questions

How do I measure an enclosure to choose the correct rectangular pan dimensions?
Measure the interior opening along both length and width rather than the exterior footprint of the enclosure. Subtract three to four inches of clearance on every side so the burner has combustion air room and the flame stays clear of the interior walls. Gas fittings and ignition hardware occupy additional space inside the cavity, so confirm those clearances before ordering.
What is the difference between center fed and end fed rectangular manifolds?
A center fed manifold introduces gas at the midpoint and splits flow in both directions, halving the distance fuel travels to the furthest port. An end fed design sends gas the full length of the manifold, which works acceptably on shorter runs. On longer manifolds, end feeding commonly produces strong flame near the inlet and noticeably weaker flame at the opposite end.
How do I prevent water accumulation inside longitudinal burner ports?
Specify a manifold with a raised internal feed hub, which keeps the gas path above the level where water settles. Pair it with a pan carrying drilled weep holes to drain water away from the assembly rather than letting it pool. Long manifolds rarely sit perfectly level once an enclosure settles, so drainage matters more here than on a compact burner.
How much media should cover a rectangular burner?
Roughly one to two inches above the ports, applied evenly across the full length. Uneven depth along a long tray produces visibly different flame heights from one end to the other, which is often mistaken for a gas supply problem. Checking depth at several points along the manifold rather than at one spot prevents that.
Can a rectangular burner run on liquid propane?
Yes, with an inline brass air mixer valve installed at the burner inlet. Propane carries higher energy density than natural gas and needs additional ambient oxygen introduced before the fuel reaches the ports. Without that mixer, an elongated propane manifold produces soot across the media and a dark yellow flame along its full length.