Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 10, 2025 ...

Dometic A/C Mod

June 08, 2021, 08:24:52 pm

After watching a couple of vids concerning improvements to a/c's, I came up with this mod to my Dometic Brisk Air 2.  Im pretty sure it would work with any Dometic application, as the air chamber and ducting would be the same.  I will say that this has really increased the airflow through the ducts, and I think the overall noise level has decreased noticeably.  I essentially built a plenum chamber to better direct the airflow into the ducts using 1/2" foam board with HVAC adhesive metallic tape.  I also replaced any foam insulation with double bubble reflective foil (I used a large size auto windshield sunshade for that material).  I will doing the rear unit tomorrow.
Mike

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Re: Dometic A/C Mod

Reply #1 – June 09, 2021, 09:23:21 pm

Mike, looks good.  I haven't looked at my AC inside for a while and can't quite remember the air flow.  It looks like the gable piece you added has no air flow through it ?  Is that there for strength to hold up the vertical piece ?
I have always wanted to do something like this, very interested.

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Re: Dometic A/C Mod

Reply #2 – June 10, 2021, 07:14:18 am

The openings for the ductwork is on either side of the open chamber; there are two.  The cold air is blown into that chamber from above directly down onto the adjustable vent.  If that vent is closed, the air would go into the ducts, but not very efficiently.  The idea behind the 'gable-like' structure is to smoothly divert the airflow to the ducts without the turbulence of the air be circulated  around inside the chamber before it would enter the ducts.  The adjustable vent is now closed off and not usable.
Mike

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Re: Dometic A/C Mod

Reply #3 – June 10, 2021, 01:02:39 pm

Update on quieting the a/c:
I still had a 'rumbling' sound coming from #2 a/c.  These are relatively new units replaced last year.  I found the noise/vibration was coming from the fan motor for the radiator.  The motor has a mount with four nuts with a rubber grommet mount for each.  I found the nuts were tightened  such that there was too much compression on the rubber grommet mounts causing a vibration that was being translated into the interior of the coach. After loosening the nuts in order to allow the rubber mounts to cushion the vibes of the motor and fan properly, the vibration has gone away.  Much quieter now.
 Bear in mind, these had not been messed with since leaving the factory, so the unit was delivered that way.
Mike

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Re: Dometic A/C Mod

Reply #4 – June 10, 2021, 03:14:22 pm

Mike,

How is the cooling aspect now overall?  Better/ worse since its not coming out of the vent on the unit.  Worth doing?

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Re: Dometic A/C Mod

Reply #5 – June 10, 2021, 03:55:48 pm

Purely anecdotal...

This morning, I opened the plenums, used the silver bubble insulation and tape to line the boxes, and blocked off the "down" vent by covering the opening on the metal plate.

It is about 100 here.  We have a friend who has been staying in our RV for a couple of months. She commented this afternoon that the interior is more comfortable, and that sealing off the bottoms are a great idea.  $16 for the bubble insulation, tape on hand, about two hours of work including scrubbing the plastic covers.

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Re: Dometic A/C Mod

Reply #6 – June 10, 2021, 04:09:56 pm

For my coach, I can really tell the difference.  The airflow has increased noticeably, and the cooling is also really improved. Once you have the metal cover reinstalled turn on the other a/c to check for cold air leaks coming from the cold side into the warm air return area.  I sealed these with that hvac metal tape.
Mike

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Re: Dometic A/C Mod

Reply #7 – June 10, 2021, 08:18:35 pm

Thanks Mike and Matt for the input.  This has moved up the list for me🙂

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Re: Dometic A/C Mod

Reply #8 – June 10, 2021, 10:15:32 pm

That is also on my list! Thanks Mike!

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