Styrofoam block in A/C unit?

**Double Eagle** · 07-03-2020, 11:10 AM

Originally Posted by huntr70

The floorplan change is the biggest reason. They switched from Dometic refers to Norcold.

Thanks for the info, good to know

**lnesomdove** · 07-08-2020, 03:30 PM

I decided to be 'different'. I liked the 'shower' option and didn't want to lose that. But what I did was use foam board to in essence, bring down the top of the plenum area closer to the racetrack vent area. Using foam, I reduced the height of the output side thus not allowing the air to turbulate in the box as the box was now shorter with a column the size of the output vent at the top of the plenum. This in theory gives the air less space to move and forces it into the race track venting. My ac cover seemed pretty air tight with the shower piece installed, and I made sure I taped the divider in place, sealed completely around the edges and made sure that when I reassembled the AC cover, there was a tight fit all around. My whole idea was to kind of replicate a small duct from the output of the AC to the racetrack duct work but also leave the dump option available.

Looking at the piece that RVAir has, it seemed to be sort of ducted to the ductwork plus blocked off the 'dump'. So far, my experience has been an increase in air flow through the vents, I lost the 'whistling' that was happening. Time will tell

**Stephen/Kerri** · 07-08-2020, 04:04 PM

I had the same thing. You need to remove those styrofoam blocks so it will vent to the rest of the trailer. Actually our 337 only came with one A/C. When we had the 2nd one added, they didn't take it them out so I opened it up to vent to the rest of the trailer. As always, I would call GD & run it by them first which is what i did. Good luck!

**gabathey** · 07-08-2020, 04:05 PM

Originally Posted by TheLexx

Ahh, this is the new product GD is installing on their trailers. For those of us who don't want to spend $180 per ac unit, folks have been performing this mod themselves with foamboard. I'm about to do it on my trailer.

These pics are from the Facebook GD Modifications Group.

You can make the foam box that isolates the cold air from the intake air, so that there is absolutely no mixing of the warm and cold air.
Attachment 27611

This is what it looks like after you put it together from foam board that's commonly available at any big box hardware store:
Attachment 27612

The box as it's about to be taped into place:
Attachment 27613

While you loose the ability to use the AC vent dump, folks who have performed the mod state that there is a massive increase in the airflow out of the ceiling vents that more than makes up for the loss of the vent dump.

We just completed this very mod this week in a 2600RB. Made a HUGE difference in noise level and air flow to the rest of the trailer. We won't go back to using the air dumps. I'm glad GD is including this block with new units.

**TeamSnow06** · 07-08-2020, 04:43 PM

I literally just installed the aftermarket RV Airflow Systems product that apparently GD is now making stock. Big Difference! Had horrible flow before that. I'd leave the block in your unit

**TheLexx** · 07-08-2020, 05:22 PM

Originally Posted by gabathey

We just completed this very mod this week in a 2600RB. Made a HUGE difference in noise level and air flow to the rest of the trailer. We won't go back to using the air dumps. I'm glad GD is including this block with new units.

AWESOME! Hey, after I saw the pics of the actual RV AirFlow kit, I got to thinking. What if we added foam to the upper part of the plenum to build it down to almost the level of the racetrack duct entrance? Then you could fabricate a triangular piece that acts as a diverter of the air to the left and right racetrack entrances. From the bottom you build it up with foam board to make the air chamber very small which will force the air into the diverter and into the racetracks.

Here's a rough sketch looking at it from front to back of the trailer (cross section basically).

Click image for larger version.

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**Maximus216** · 07-08-2020, 06:48 PM

Originally Posted by TheLexx

Ahh, this is the new product GD is installing on their trailers. For those of us who don't want to spend $180 per ac unit, folks have been performing this mod themselves with foamboard. I'm about to do it on my trailer.

These pics are from the Facebook GD Modifications Group.

You can make the foam box that isolates the cold air from the intake air, so that there is absolutely no mixing of the warm and cold air.
Attachment 27611

This is what it looks like after you put it together from foam board that's commonly available at any big box hardware store:
Attachment 27612

The box as it's about to be taped into place:
Attachment 27613

While you loose the ability to use the AC vent dump, folks who have performed the mod state that there is a massive increase in the airflow out of the ceiling vents that more than makes up for the loss of the vent dump.

Is there a link with the dimensions? And is there a way not to have to remove the 4 bolts?

**TheLexx** · 07-08-2020, 06:55 PM

Originally Posted by Maximus216

Is there a link with the dimensions? And is there a way not to have to remove the 4 bolts?

If you perform the mod as I described, you shouldn't have to remove the 4 bolts AFAIK.

**Maximus216** · 07-08-2020, 07:24 PM

Originally Posted by TheLexx

If you perform the mod as I described, you shouldn't have to remove the 4 bolts AFAIK.

The pics show the holes in the foam for the bolts. It's just the two bolts on that side.

**frank4711** · 07-08-2020, 08:09 PM

I just did my bedroom after doing the living area, the improvement is amazing. https://rv-airflow.myshopify.com/ ... I would say the kit is a bargain based on results. Nice to have a product that meets expectations/claims. A cool RV in SW FL with temps in mid 90's is priceless. If you are a good DIY I am sure you can make something "like" it. later Frank