ATF: Bighorn - Whisper Quiet ducting design issue

[danemayer]

Winter months in Arizona on each end reach the low 90's front time to time, do you think that two units will keep us happy? We were going to head South in early Oct. Chris

Our 2 A/C units (pre-Whisper) have to work pretty hard even in an 85 degree arid climate if there's intense afternoon sun on the side of the coach. And we have sun shields on the the dual pane windows. I measured the temperature at the mid-living room ceiling duct the other day - around 50 F. So the A/C units are working well. But that just doesn't keep up with the afternoon heat load. If I run the A/C units at a low set point before the afternoon sun hits, I can stay ahead.

We've been in temps up to 108 and as long as we stayed on top of it, we've managed. The biggest problem is when arriving at a park and setting up in the afternoon. It's hot outside. The sun is intense. The coach is hot. It can take most of the evening for the A/C units to catch up. That's when I wish we had 3 A/C units.

My experience is that unlike a residence, where you can set the temp at 75 and it just works, you need to manage the RV thermostats more actively to deal with the heat load.

By the way, the big advantage of Whisper Quiet is the shared ducting. Once your temperature inside is comfortable, you can set the thermostats so that the unit furthest away is doing the work. And then it's quieter where you are.

 

[SNOKING]

Dan, I put a piece of swimming pool noodle in the duct to separate the BR from the other unit. It really pumps out cold air in the BR with that in place. Will see, having a cool place to sleep is GOOD! We will be moving into the trailer full time in four weeks or so if the house closes on schedule, then the learn curve will be in full force! Would like to get it working the best it can before leaving the NW for Arizona. Maybe DW is right, and we should purchase the park model in Arizona that she wants. Six months in the BH in the NW and six months in the park model in AZ.

Chris

 

[travelin2]

Dan, I put a piece of swimming pool noodle in the duct to separate the BR from the other unit. It really pumps out cold air in the BR with that in place. Will see, having a cool place to sleep is GOOD! We will be moving into the trailer full time in four weeks or so if the house closes on schedule, then the learn curve will be in full force! Would like to get it working the best it can before leaving the NW for Arizona. Maybe DW is right, and we should purchase the park model in Arizona that she wants. Six months in the BH in the NW and six months in the park model in AZ.

Chris

Might be a fix but certainly shouldn't have to do that. Each individual AC should be able to cool and maintain in moderate heat. Only both AC units if you're in a hot humid environment. Plus many parks and CG we have visited only supply 30A. What's the "fix" for that?? (rhetorical question-doesn't require an answer)


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[SNOKING]

"Plus many parks and CG we have visited only supply 30A. What's the "fix" for that??"

Retirement! Camp in the spring and fall!

 

[travelin2]

"Plus many parks and CG we have visited only supply 30A. What's the "fix" for that??"

Retirement! Camp in the spring and fall!

HA!! We are and do! Just attended the Virginia and Maryland rallies. Been in the 90's here. Too hot too soon for the mid-Atlantic states.
Have the old style AC and 50A so we're chillin'


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[Gary521]

It's possible to run both AC's on 30 AMP but NOTHING else.

 

[Aandaar]

I have done it. Just don't hit the microwave. Set the ACs to two different temps. That way they wont spike the power by both coming on at the same time.

I have sat in my front yard with both running and TV on.


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Chuck, Victoria, and Miss Callie

 

[Gary521]

Both AC's, 28 amps for me.

 

[billvenohr]

I received an email from Jim Fenner today with an attached service bulletin. I couldn't figure out how to attach it, but below is the beginning:

TECHNICAL SERVICE BULLETIN [COLOR=rgb(100.000000%, 100.000000%, 100.000000%)]98-01-19

Dometic Blizzard AC water migration into return air cavity
Description
Blizzard Whisper Quiet Dometic AC units on the Landmark, Big Horn & Big CountryModels. It has been determined that there are mounting holes that are not used, Theseholes will need to be plugged to prevent condensation or water from entering the ACducting on the interior of the RV. Additional holes will also need to be added to the panto allow all the water to drain from the pan.
VIN Range Effected
5SFBG4325GE314259 to 5SFBG3428HE329381

It it has you plug up a few holes and drill a bunch more. The bulletin has diagrams and pictures and the procedures. It is being sent to dealers too. I hope it works!
[/COLOR]

 

[SNOKING]

I received the TSB this morning and have asked if I can share it here.

Here is the answer:

"I would prefer that you do not. We have to verify the unit is affected by this before we can send the info out to retail customers or dealers. This is unit specific and only certain models were affected by this issue. I fear that if the info is put on the forum we may see customers that do not have an effected unit going in and modifying the a/c causing unnecessary issues with their units."

Because I have all ready sealed the four extra mount holes and it is not convenient to take our trailer to a dealer right now, I am going to drill the extra holes myself.

So if you have water leaking into your trailer contact customer service to verify that your unit is included in the TSB.

I am also going to use dielectric grease on the thermostat cable coupler(the phone cable style coupler).

On edit I just received this:

"We have letters sent out to all customers with affected units advising them the procedure to remedy the problem. If a customer feels that their unit is affected by it they can contact us to verify and we can send them the info at their request if the unit is affected by this TSB."

So it seems that they have jumped right on this with a plan to fix the effected units. Chris

 

[Bones]

So is this a dometic issue or is this an installation issue?

 

[SNOKING]

So is this a dometic issue or is this an installation issue?

Mostly a Dometic issue. The extra mounting holes were added without notifying the installers to seal the unused ones, the lack of enough drain holes is 100% on Dometic. Chris

 

[Bones]

Mostly a Dometic issue. The extra mounting holes were added without notifying the installers to seal the unused ones, the lack of enough drain holes is 100% on Dometic. Chris

Thanks

 

[Westwind]

Yes, the two mentioned problems are Dometic, but the trailer overhead venting problems point towards Heartland design and production management. Hopefully with 20 pages of posting this issues have gotten back to the Heartland staff that can do something to correct the installation procedures (QA) and then on to the warranty staff who can advise dealer repair staff on how to correct the problems that the current owners are having.

 

[billvenohr]

I had a mobile RV repair technician come out and performed the service bulletin on both of my air conditioning units. They only have you sealing two of the original mounting holes--I guess the others aren't in a location of concern. Then you drill lots of holes in the plastic base to drain better. We also found quite a few holes that had debris from installation (wood shavings, plastic, etc.) that were clogging up existing holes and opened them up. It seems as though sloppy installation contributed to all this along with the draining in the right location. I've had both air conditioning units running for over 6 hours now with no leaks. Since the technician wasn't a "Heartland" warranty approved tech (he is Dometic) I paid him--hope Heartland comes through with my reimbursement without problems. For those with flow questions, the service bulletin does not address this.

There is damage to the ceiling in the form of water stains. Anyone have any idea how hard this is to repair? It seems to be some sort of "paper" applied to the ceiling material. While this is a warranty issue, I have some concerns about how quickly my dealer can do this (and how competently).

 

[SNOKING]

I had a mobile RV repair technician come out and performed the service bulletin on both of my air conditioning units. They only have you sealing two of the original mounting holes--I guess the others aren't in a location of concern. Then you drill lots of holes in the plastic base to drain better. We also found quite a few holes that had debris from installation (wood shavings, plastic, etc.) that were clogging up existing holes and opened them up. It seems as though sloppy installation contributed to all this along with the draining in the right location. I've had both air conditioning units running for over 6 hours now with no leaks. Since the technician wasn't a "Heartland" warranty approved tech (he is Dometic) I paid him--hope Heartland comes through with my reimbursement without problems. For those with flow questions, the service bulletin does not address this.

When I go up to drill the holes, I ready sealed the extra mounting holes, I am taking my little vacuum cleaner and dielectric grease for the data cable connector contacts. I suggested to Heartland that that should be included in the TSB, if cable ends look ok and do not need to be replaced along with the couple according to the TSB under step 5.

Chris

 

[wehavefun]

I had placed towels in duct work forward of bedroom vents, rearward of living room vents. It made a big difference. I am considering spray foam for permanent fix. I had used a Milwaukee inspection camera with a 3 ft wand / camera, there are lots of places for air to escape! I would estimate that on the ends of the runs there is at least 3/8" if not 1/2" gaps that appear to dump air into the caps.

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[TravelTiger]

I had placed towels in duct work forward of bedroom vents, rearward of living room vents. It made a big difference. I am considering spray foam for permanent fix. I had used a Milwaukee inspection camera with a 3 ft wand / camera, there are lots of places for air to escape! I would estimate that on the ends of the runs there is at least 3/8" if not 1/2" gaps that appear to dump air into the caps.

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I don't know if you'd want something so messy, difficult to control and impossible to remove as spray foam. Metallic duct tape works to do the same thing, and you could remove it if you had a unit fail and needed to try to cool the whole rig with a single AC.


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[SNOKING]

I don't know if you'd want something so messy, difficult to control and impossible to remove as spray foam. Metallic duct tape works to do the same thing, and you could remove it if you had a unit fail and needed to try to cool the whole rig with a single AC.


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I could pull out the piece of swimming pool noddle that I put in to separate the bedroom if I want. Chris

 

[BigJim45]

This is what I got from Heartland today




It has been determined that due to improper build specifications from Dometic on its Blizzard AC System air flow requirements, the AC system has too high of a static air pressure. This static air pressure causes the accumulated standing water to splash into the return air duct. This condensation can cause damage if not corrected immediately.

Heartland has work closely with Dometic to indentify the appropriate repair and will have an authorized dealer correct this situation at no expense to you, the owner.

At your earliest convenience, you will need to call your local Heartland dealer and schedule an appointment to have this corrected as soon as possible.