In most homes, old and new, the wall behind the washer, dryer and laundry tub is referred to as the “Mechanical Wall” as it generally contains the primary waste stack, the initial plumbing manifold and the 4” dryer duct. Because of all these “mechanicals”, this wall is typically thicker and achieved by being framed with 2x6 studs or furring strips added to a 2x4 wall.
A nominal 2x4 measures 3.5 inches: a dryer duct measures 4.08 inches and if it has any fittings, measures 4.25” and has no ability to deform. A 4 inch plumbing stack with the required cleanout requires 5.25 inches of stud depth.
If you add one furring strip (a 1x2) to the front or rear face of the respective wall, you will be able to use our deeper and generally preferred models 425 or 480 Dryerbox. These boxes exhibit an almost round port for the duct to penetrate into the receptacle. The 350 Dryerbox model exhibits a more restrictive oval hole as the 4” round pipe is deformed to fit into a 3.25 inch deep hole.
When possible, we recommend the 425 or 480 models due to their inherent energy saving aspects. The Model 480 is becoming popular as it offers the builder the freedom to use a dryer that is or is not on a pedestal and the unit can also be mounted in an up or downward direction.