AC air flow problem SOLVED

[Todster]

For those who come across this same issue, I’ve taken this one step further. Our 3513 has (3) 15k ac units but with just 2 on low it always felt like there was still poor air delivery from the supply registers. Even more noticeable after the sheet metal and sealing up all the leaks.

I found some 5” registers online that offer much better airflow. In addition, I am cutting in more registers as the living area only had (1) little supply. I’m in the middle of this upgrade but it’s already night and day.

Red marks are where the original registers are. Blue will be the newly cut in registers that are fully adjustable.

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[xfirechief20]

Our new 2019 Landmark 365 Phoenix had no air flow from 2 of the 3 units. The dealer was allowed to remove the 2 units per Landmark engineering and they found the roof opening had never been opened up. The sealing material was removed and we now have some air flow. That was just some of the minor problems we encountered the first week we had the coach. The most serious was all the tanks,(black, 2 gray and fresh water) were hanging down and falling out after only 18 mile trip to our snowbird home. The list goes on and on but most have been fixed. Waiting to see why we only have one heat pump where our build sheet shows a second one on option list.

 

[wdk450]

I have heard over the past few years that Dometic has made significant improvements to the Brisk Air II models, while keeping the same model nomenclature. I just replaced my 11 year old Brisk Air II with a new one, as the compressor was overheating and cutting out in hot weather. As we did the switchout, the old "TIMK" air diverter plate came out of the inside plate. My question is: Is the TIMK air diverter plate still needed on ducted units, or did the Dometic "upgrades" make it unnecessary?? I improved mine with metal ducting tape and put it back in place between the DS and ODS ducting inlets.

2nd question: IF the TIMK diverter plate is a necessary owner addition for good cooling, why isn't it in the Forum Library? All the newbies could benefit.

 

[danemayer]

Bill,

I haven't heard much about the TimK modification in a few years. But it is referenced in the Heating and Cooling User Guide, with a link to this thread.

 

[wdk450]

Thanks , Dan for directing me to where the info is. I hope the newbies can find it.

Which brings up the "hot" question: If YOU were buying a new rig would you install the "Tim K Tent" right away???

 

[danemayer]

Our 2011 Landmark is 39' long. The living area A/C unit is mid-ships over the kitchen island. With the cold air dump located there on 2011 models, you didn't get much airflow into the sitting area of the living room.

On newer units that don't have a cold air dump, I think the airflow to the sitting area is probably better. And the TimK Tent mod probably doesn't work because of the different design.

Is the TimK Tent helpful on older coaches. I believe we got some improvement in airflow to the sitting area, which we needed.

Will it work with newer A/C units. You'll have to let us know.

 

[wdk450]

On newer units that don't have a cold air dump, I think the airflow to the sitting area is probably better. And the TimK Tent mod probably doesn't work because of the different design.

Is the TimK Tent helpful on older coaches. I believe we got some improvement in airflow to the sitting area, which we needed.

Will it work with newer A/C units. You'll have to let us know.

Dan, and All:
Be aware that the Tim K Tent baffle sits OVER the cold air dump louvers, and should make them pretty ineffective.

I found that the non air conditioning "RV Professional" I used for lifting to the rooftop muscle on most of the R&R work yesterday forgot to re-install the sheet metal baffle that extends the return and cold air divider wall up to the base of the rooftop unit. After running the new AC for about 3 hours with no cooling in 103 outside temperatures, I got up and opened the inside access to discover this. I found the plate outside with the old unit. One thing that disturbs me is that there were no holes for sheet metal screws to securely mount these 2 metal plates together - Rather the old install had self adhesive foam rubber insulation holding the parts together. The old insulation was all torn up, so I used a lot of my metal duct tape to put the divider extension in place. I may see if I can fit my drill in the tight space to drill a few holes for sheet metal screws, also. I couldn't find sheet of this same self adhesive foam insulation online, so I think I will get some adhesive spray and use a small amount of the excess reflective foil/bubble wrap insulation I have around. I am thinking that this insulation on the inside of the return air side (on the metal divider by the cold chilled air side of the AC) is there to prevent condensation and dripping from the humid return air flowing on the cold metal divider from the supply air.

 

[bebelynaccessdo]

I have heard over the past few years that Dometic has made significant improvements to the Brisk Air II models, while keeping the same model nomenclature. I just replaced my 11 year old Brisk Air II with a new one, as the compressor was overheating and cutting out in hot weather. As we did the switchout, the old "TIMK" air diverter plate came out of the inside plate. My question is: Is the TIMK air diverter plate still needed on ducted units, or did the Dometic "upgrades" make it unnecessary?? I improved mine with metal ducting tape and put it back in place between the DS and ODS ducting inlets.

2nd question: IF the TIMK diverter plate is a necessary owner addition for good cooling, why isn't it in the Forum Library? All the newbies could benefit.

the facts have been discussed is really important. Keep doing that

 

[pnnf]

I know this is an older thread but man oh man am I blessed to have found it! The "tent" is AMAZING!! I have a 2007 Grand Canyon and went looking for what to do to help the poor air flow before another summer gets going. I followed what everyone else was doing: cleaned the ducts ,bought some hvac tape and cleaned up all the vents and then made the "tent". I started out with cardboard because i was a bit skeptical. Even with poorly done cardboard the airflow was greatly improved. I then followed along and went to lowes and bought a 4" x 24" piece of stove pipe to get my metal and went to work. It was a bit tricky but after i got the slopes ,angles and length right it was a breeze taping it all together. The airflow is even stronger. I can feel one vent across the coach now and that never was the case. If anyone comes across this thread ,weather you have bad air flow or not, this is a must mod/upgrade! Thank you for this Tim!

Much appreciated~

 

[jbeletti]

I know this is an older thread but man oh man am I blessed to have found it! The "tent" is AMAZING!! I have a 2007 Grand Canyon and went looking for what to do to help the poor air flow before another summer gets going. I followed what everyone else was doing: cleaned the ducts ,bought some hvac tape and cleaned up all the vents and then made the "tent". I started out with cardboard because i was a bit skeptical. Even with poorly done cardboard the airflow was greatly improved. I then followed along and went to lowes and bought a 4" x 24" piece of stove pipe to get my metal and went to work. It was a bit tricky but after i got the slopes ,angles and length right it was a breeze taping it all together. The airflow is even stronger. I can feel one vent across the coach now and that never was the case. If anyone comes across this thread ,weather you have bad air flow or not, this is a must mod/upgrade! Thank you for this Tim!

Much appreciated~

I'm not sure TimK is around here anymore but his mod idea lives on. Bear in mind that it does affect the down-draft (dump) feature if so equipped.

 

[timk]

this is a must mod/upgrade! Thank you for this Tim!

Much appreciated~

Your welcome.