Jan 30, 2026

DIY Guide: How to Vent the ZERO BREEZE Mark 3 Through an RV Roof Fan

A cozy van conversion interior features a full-size bed with white bedding, warm wood-paneled walls and ceiling, built-in cabinets, soft lighting, and a roof vent fan, creating a comfortable sleeping space for van life travel.

One of the most common questions we hear, especially from van lifers and RV owners, is:

"Can I vent the heat from my Mark 3 through my roof fan without cutting a new hole in my van?"

The answer is YES. By utilizing your standard RV roof fan, you can create a seamless, removable exhaust setup. This allows you to vent hot air out directly while keeping your vehicle secure.

Here's how to create a simple DIY board to vent your Mark 3, taking the popular MaxxFan Deluxe as an example.

What You'll Need

Before you get started, prepare the following items.

Materials

PVC foam board (thickness should match the original screen frame)
ZERO BREEZE exhaust duct adapter with clips and screws (coming soon to our official website)
Mark 3 rear exhaust duct (with rear outlet adapter connected)

Tools

Pen or marker
Utility knife
Screwdriver

Step-by-Step Installation

Step 1: Remove the screen

Twist the four locking knobs on the MaxxFan Deluxe frame and remove the screen.

The MaxxFan Deluxe RV roof fan is displayed as the example model for this DIY guide, showing the standard screen and locking knobs where the custom board will be installed.

Step 2: Trace the screen outline

Place the screen on your PVC foam board and trace the outer edge with your pen.

Two-step roof fan vent preparation is shown side by side: on the left, a circular screen mounted on a foam board; on the right, the board with a traced circular cutout and a utility knife and pen placed beside it, illustrating how to mark and cut a vent opening for a portable ac.

Step 3: Cut the screen shape

Carefully cut out the outer shape you just traced.

The circular cutout board is placed beside a utility knife and pen.

Step 4: Mark the exhaust opening

Use the inner ring of the exhaust duct adapter as a template to mark the hole (⌀150mm). Position it off-center (to one side) of the board, not in the middle, to ensure smooth exhaust airflow through the roof fan.

Marking the exhaust opening is shown side by side: on the left, the inner ring of the duct adapter is used to trace a 150mm circle; on the right, the traced outline is shown positioned off-center on the board to ensure smooth airflow through the roof fan.

Step 5: Cut the foam board

Carefully cut out the inner ⌀150mm circle.

The PVC board is shown with the 150mm exhaust hole fully cut out and positioned off-center, placed next to a pen and utility knife, ready for assembly.

Step 6: Attach the duct adapter

Place the duct adapter flat on the surface of the board, covering the opening. Secure it with screws.

Important Installation Tips:

The adapter must sit entirely on one side of the board. Do not push or insert it into the hole, as it may hit the fan blades, causing malfunction.

The duct adapter installation is shown from both sides: on the left, the adapter sits flat on the top surface; on the right, the bottom side of the board is displayed, confirming the adapter covers the opening without protruding through to the other side.

Insert the screws into the four flat holes on the outer ring to ensure a tight, flush fit. Do not use the four raised holes.

Side-by-side views illustrate inserting screws into the adapter's flat outer holes to secure it to the board, ensuring a flush fit and avoiding the raised holes.

Step 7: Connect the exhaust duct

Stretch the free end of the exhaust duct slightly and insert it into the adapter. This ensures the clips can lock the duct securely in place.

The exhaust duct is inserted into the adapter on the white PVC board, with two locking clips placed beside it, ready to secure the connection.

Step 8: Lock the duct in place

Line up the raised tab on each locking clip with the matching notch on the adapter, then press it in until you hear a clear "click".

Side-by-side views demonstrate securing the exhaust duct: on the left, a finger presses the locking clip into the adapter's notch; on the right, the clip is fully installed, locking the duct in place.

Step 9: Install the board

Place your new board into the fan opening (replacing the screen) and twist the four knobs to lock it in place.

Side-by-side views demonstrate the final installation: on the left, the prepared board is ready; on the right, the board is inserted into the roof fan opening, secured by twisting the four locking knobs.

Note: Once the adapter is installed, we recommend leaving it screwed into the board. Removing the screws repeatedly may loosen the holes in the foam. If you need to remove the setup, simply take out the entire board.

You're All Set

Connect the exhaust duct to the Mark 3, then open your roof fan lid. Your Mark 3 is now ready to vent hot air directly outside.

This setup creates a sealed, vertical exhaust path that efficiently vents heat out of the vehicle without compromising your privacy or safety. It's easy to install, easy to remove, and requires no permanent modifications.

Have More Questions?

If you have additional questions about using the ZERO BREEZE Mark 3 portable AC in your RV, van, or other setup, feel free to reach out to us at support@zerobreeze.com.

We're here to help, and we'll take it from there.