Transition Request Form

What is Connection 1?

Connection 1 is the bottom opening — typically the furnace collar or the existing duct opening you are connecting from. Stand in front of the unit facing it straight on.

Width (left to right)

Measure the opening from the left edge to the right edge as you face it. This is always your horizontal measurement.

Depth (front to back)

Measure from the front edge to the back edge going away from you. This is always your front-to-back measurement.

What is Connection 2?

Connection 2 is the top opening — typically the existing duct you are connecting into. Measure it the same way as Connection 1: width left-to-right, depth front-to-back.

Connection Types

• Plenum Bend — a folded flange bent outward, sits over the furnace collar. Most common on the bottom connection.
• 1" Outside Flange — flange folds outward 1". Used when the transition needs to sit outside the existing duct opening.
• 1" Inside Flange — flange folds inward 1". Slides inside the existing duct opening.
• S-Lock — a formed channel that accepts a drive cleat. Standard duct-to-duct connection. Most common on the top connection.
• Capped — solid top, no opening. Used when the transition is a dead-end plenum or you are capping off a run.

Edge Gaps — The Short Version

Edge gaps describe how the top duct is offset from the bottom opening. If both openings are the same size and perfectly centered, all gaps are 0. If the duct is bigger, smaller, or shifted, you need to tell us by how much and in which direction.

How to Measure

Stand facing the unit. Look at the left edge of the bottom opening and the left edge of the top duct directly above it.

• Positive number (+) — the top duct extends beyond the bottom opening on that side. Example: top duct hangs 2" to the left of the furnace → Left gap = +2
• Negative number (−) — the bottom opening extends beyond the top duct on that side. Example: furnace sticks out 2" past the duct on the right → Right gap = −2
• Zero (0) — edges are flush on that side.

The Auto-Calculate

Once you enter one side, the opposite side calculates automatically based on the size difference between the two openings. You can override it if your field measurement doesn't match.