We’ve been full time RV’ers now for about 2 years!

The Air Conditioners have been an issue in EVERY RV we have owned.

Mostly the complaints have been surrounding poor cooling and poor efficiency but in our new 5th wheel we have also struggled with the overwhelming loudness of the roof air conditioners!

I searched the internet extensively and found only one product that made promises to quiet the air conditioner but it was $250.00 and when I studied it, I came to the conclusion that I could do similar modifications in more of a DIY fashion to reach an acceptable result.

The results were incredible!

I found a simple way to modify the Dometic RV air conditioner which will make it more quiet, more efficient and circulate more air!

The problem is not the equipment! It’s the RV factory install!

If you haven’t already, I suggest you watch the video on YouTube. This video shows step by step how to modify your air conditioner unit with cheap parts.

The items you will need to buy are Double Reflective Insulation and Foil tape. These are links to my Amazon Store and using them will earn me a very small referral commission at NO EXTRA COST to you!

This job is very easy, but may look intimidating to some. Let’s go through the steps to improve your RV A/C!

**Turn the power off to the AC unit.

1: Remove the filter and decorative vent cover. There are usually between 4-6 Philips screws holding this.

2: Remove the metal mounting bracket. Generally this is held on with 4 long screws. The screws in my unit were 3/8”.

3: When you remove the metal bracket, be mindful of the baffle that separates the warm air return and the cold air intake. This baffle consists of two separate pieces of overlapping sheet metal and they are only joined by foam tape. Try to keep these together in their original position.

4: There is no need to disconnect any wires. Let the metal mounting plate dangle while you work through the next steps.

5: Remove all the loose foil tape from the factory install.

6: Apply new foil tape in long horizontal strips. Don’t apply foil tape to the rubber roof flaps (if you have them). Meticulously, apply the foil tape to the ducts, corners and all surfaces to prevent ALL unwanted air leaks.

7: Start preparing the double reflective insulation. Ours was 5.5 inches tall so we cut long strips to wrap around the inside of the box. Carefully tape the reflective insulation in place and around the ducts. At this point, you should tape down the rubber roof flaps (again, if you have them)

8: Now turn your attention to the baffle on the mounting plate. Cover BOTH sides of the baffle with the double reflective insulation taping it securely.

9: Cut a piece of the double reflective insulation to cover the louvered air dump port. We are blocking this feature! Tape it on the inside of the mounting plate. Once the mounting plate is reinstalled we will tape it on the underside as well.

10: Reinstall the metal mounting plate with the 4 long screws. 2 of the screws are easily visible and 2 are now obscured (on the cold air side) but with a little patience you should be able to reinstall them. You need to install the 4 long mounting plate screws loosely at first and make sure the plate is seated correctly in the box before fully tightening.

11. Apply a little more tape to each side of the baffle to ensure there is no cold air making its way into the warm air return.

12: The last step is to trim off the tabs on the trim cover. The tabs are located in the area of the louvered dump port. I found the easiest way was to score them with a knife and snap them off.

At this point you are ready to reinstall the trim and you’re done!

We were shocked at the improvements this has made.

We realize now that we had a huge amount of cold air loss and now that the system is operating they way it was intended. The performance increase has been huge! We struggled to keep our 5th wheel cool in the 95 degree days of Myrtle Beach and now we often feel too cold and raise the temperature. The air flow has increased significantly as well.

Also, the units seem much quieter. I did try to analyze the decibels before and after and I only found about a 2-3 decibel reduction. However, it does seem much quieter and I think that is because the annoying high pitch of the AC is lower and the hissing sound is gone!

This was a significant improvement to our 5th wheel!

Feel free to reach out to me with any questions. I will try my best to help. Please know that I am not an HVAC technician.

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Cheers!

Corey