Air Box to Use with Dometic Penguin II Unit for Ducted Application

Updated 11/09/2025 | Published 10/30/2025

Question:

Good afternoon, Will this AC unit fit my vehicle. The electrical interface and the unit look and feel seem very close. I am adding pics. This is for just the front bedroom unit A ducted unit.. Thx. Tim

asked by: Tim D

AC Unit and Feet
(click to enlarge)

Expert Reply:

Hey Tim, the Dometic RV AC Unit part # DMC53ZR that you referenced can be used in your ducted application but you will need a new air box too with the part # DMC43ZR since this will not work with the air box you have now.

Thankfully your RV roof is white and not black otherwise that might be hot on your feet!

expert reply by: Jameson C

Tim D.

11/6/2025

I am confused. What is an air box. The unit just sits on the 14.5 x 14.5 hole once I remove the damaged one.

Jameson C.

11/6/2025

@TimD Was there a low portion of the assembly that was on the inside of the RV that had a vent system and controls you'd normally access from inside the RV?

Tim D.

11/7/2025

@JamesonC I installed the AC exactly as the other. However, compressor works but no air. I am wondering if there’s a switch I need to do to tell it, theirs no air box and that it’s ducted. I would expect at very least fan would work

Tim D.

11/7/2025

@JamesonC Unfortunately a manual was not enclosed in the box with the Dometic AC so I don’t know what the dip switches are for a ducted AC running on 20 amp. But I can tell you the wiring is correct. The control board on the old unit is nothing like the control board on new unit.