ATF: Bighorn - Whisper Quiet ducting design issue

BusManRG

Well-known member
Currently we are only on 30 amp service which made it easy to confirm that the units share a common run. So far it appears that we have blocks at the ends of the exhaust runs, but I wouldn't call the air flow "forceful"! We removed the directional vent covers and the amount of air dumping into the rooms definitely increased! We're thinking of just leaving the covers off...the options I've seen on the web look like they would still hinder the amount of air allowed through the vents. Any ideas? The uncovered open holes in the ceiling don't make the best looking design feature!!

Sandy
 

SNOKING

Well-known member
In think the vent is just spreading the air flow out on you, making it seem like there is less air flow.

We love our 2017 BH3575el, however this is one area where they could have done better. Chris
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
I bought these, with the 1/4" extension:

http://www.dwincorp.com/products.php?product_id=11

At first I only bought for the outflow, but realized they are different color/size than the original. I bought ones for the inflow side as well.

Pros:

• More air seems to come out the vent in a more downward, instead of horizontal, fashion.
• They are easily adjustable like the OEM.

Cons:
• They are pricey - shipping is high.
• They don't come with screws, so you have to buy them separately.
• The don't fit the hole the same as the previous model, so getting all 4 screws into the ceiling is difficult.
• Pulling the center-held louvered section to get to to the foam filters can strip the screws and pull the vent off if you are not careful.
 

Ldo

Active Member
Hello All. Sorry for the delayed post...campground WiFi :( Finally broke down and got a MiFi so can connect and stay connected :) Our AC saga continues. The dealer 'fixed' the AC units by cleaning the construction debris stuck in the drain holes of the pans so they both worked when we got Baby Huey back. The front unit worked once and will not turn back on. It still shows no heat pump on the control panel but the serial number designates that is has one, so the dealer is expecting that the control panel is bad or not programmed properly. A call from the dealer to Heartland about repairing the water stained ceilings wasn't a quick and easy transaction. The dealer is reluctant to do the repair as the ceiling in the LR is coffered and they would rather it is fixed at the factory. We agree. The first CS rep wasn't authorized to allow that so it went up the chain a bit and now I need to call a certain rep to schedule an appt. They are balking about putting us up if the repair takes more than a day. The argument is that Dometic is responsible for the problem, not Heartland. Other than this continuing AC issue, we really love our new home and are excited to be so close to being on the road...just over a month to lift off :) Hope to see some of you out there! Now that we have good WiFi I'll try to keep you all better posted.
I got a recall on my twin Blizzards Dometic and went back to dealer who dealer prepped the unit before delivery. Technician drilled 16 holes in each collection pan and rechalked mounting bolt holes. A C seems to be working great. Drilling and chalking is a fix per recall. Lake Shore R V was excellent as was Chet, the tech.

Sent from my SM-N920V using Tapatalk
 

ceh333

Member
I am new here. For the past year, we have been looking at fifth wheels for full time RV'ing and have finally decided on the Bighorn 3760EL. This is a beautiful unit with all the "bell & whistles" which set it apart from some of the others. But after reading these posts about the duct work problems, I am kind of skittish. Then I met someone who heard me talking about it and he says he bought the same model. He mentioned that his had same problem and brought it back to dealer. The dealer got with the factory and had it sent back for a "new roof". When he got it back, it was a new roof but the design was still the same. The problem had been "fixed" with some taping here & there. He said the flow was somewhat better, but the temperature has not yet been tested because conditions were not hot enough yet. My question is, has Heartland been able to redesign the duct work to alleviate these problems that we, as consumers, should not have to deal with DIY solutions? The dealer I am working with says yes, but we all know they will tell you anything to make a sale. That is a lot of money to spend on an RV to not be completely satisfied. Thank you for reading....
 

travelin2

Pennsylvania Chapter Leaders-retired
I am new here. For the past year, we have been looking at fifth wheels for full time RV'ing and have finally decided on the Bighorn 3760EL. This is a beautiful unit with all the "bell & whistles" which set it apart from some of the others. But after reading these posts about the duct work problems, I am kind of skittish. Then I met someone who heard me talking about it and he says he bought the same model. He mentioned that his had same problem and brought it back to dealer. The dealer got with the factory and had it sent back for a "new roof". When he got it back, it was a new roof but the design was still the same. The problem had been "fixed" with some taping here & there. He said the flow was somewhat better, but the temperature has not yet been tested because conditions were not hot enough yet. My question is, has Heartland been able to redesign the duct work to alleviate these problems that we, as consumers, should not have to deal with DIY solutions? The dealer I am working with says yes, but we all know they will tell you anything to make a sale. That is a lot of money to spend on an RV to not be completely satisfied. Thank you for reading....

We have the "whisper quiet" on our 3 month old 2017 3270RS. I will say the front AC is far from quiet but the rear unit is much quieter than our previous HL unit that had the AC unit protruding from the ceiling. On ours the ductwork runs from fore to aft. Both units blow exceptionally cold air. In fact I have the 2 most rear vents partially blocked so the cold air is not blowing down our necks while seated in that corner of the coach. In 90+ degree sunny weather in September at Chattanooga and Myrtle beach our coach was comfortable for us. At night we only run the rear unit as neither of us like the noise or the cold air blowing down on us while in bed.
Whatever issues HL had with their early production doesn't exist in ours.


Sent from my iPhone using Tapatalk
 

Toy1Ton

Toy 1 Ton
On the 3760 EL the living room air conditioner will not be supplying cold air to the bedroom because the duck work stops at the skylight in the bathroomI know this because I have a 3760 EL late 2016
 

StrongJava

Well-known member
Hi Jim and everyone else!

I'm working my way through this ENTIRE thread :)

I'm in a 2008 Bighorn and was shocked when I pulled the vent covers and found they had used, basically, aluminum foil to seal between the ceiling and the duct. Not very effective, so I'm going to get some duct tape and try to make a better seal.

I have heard others say the old style (like I have) is more effective, but frankly with my tinnitus, I have got to get it quieter in here. I'm planning to do an upgrade and I want to move to a whisper quiet design. However, my existing duct is 1-1/2"D by 8"W, so it has just over half of the cross-sectional area called for in the Dometic manuals.

What I'm trying to plan is replacing my ACs with newer and quieter units, and tying both into the duct work. I may have to tear down my ceiling panels to do this. Has anyone else ever done something like this? I'm in the gathering info stage.

Tim

Just so everyone understands how the whisper quiet is designed ... you cannot access the air conditioner from the inside of the coach. It does not stick into the inside of the coach. The ceiling is one solid piece and on the off-door side there are louvered opening about every 3 feet the length of the coach and this is where the cool air enters the coach. On the door side of the coach there are louvers about every 3 feet the length of the coach and these louvers have filters on them. This is the return air of the system. In order to access the ductwork you will have to go on the roof and remove the air conditioner unit. Even if you could remove a ceiling panel on the inside I don't know that you could gain access to the AC unit. In order to gain access to the ductwork you would have to remove the roof (I think) which is really not feasible for a repair of the ductwork.
Also the 'Tent in the vent' type fix could not be done in this type of unit. Also there is not a 'quick cool' feature on the AC.
In this type of system the bedroom AC blows cooled air the whole length of the coach and the living room AC blows air the whole length of the coach. So the living room air is traveling through the ductwork from the rear of the coach toward the front of the coach (some does go from the AC unit toward the rear of the coach) and the bedroom air is traveling through the ductwork from the front of the coach toward the rear of the coach (a small amount does travel from the AC unit toward the front of the coach). (confusing isn't it) Anyway the air meets somewhere in the middle. Now going a step further if you block the duct somewhere after the last vent by the stairs going into the bedroom, the living room AC would work to cool the living room/kitchen section and the bedroom AC would work to cool the bedroom bathroom. Haven't tried that yet but am considering trying.

BTW - By not having an AC unit protruding into the inside of the coach and having a 'clean' ceiling gives the inside of the coach a 'slick' look, but personally the 'old style' worked better.
 

danemayer

Well-known member
Hi Jim and everyone else!

I'm working my way through this ENTIRE thread :)

I'm in a 2008 Bighorn and was shocked when I pulled the vent covers and found they had used, basically, aluminum foil to seal between the ceiling and the duct. Not very effective, so I'm going to get some duct tape and try to make a better seal.

I have heard others say the old style (like I have) is more effective, but frankly with my tinnitus, I have got to get it quieter in here. I'm planning to do an upgrade and I want to move to a whisper quiet design. However, my existing duct is 1-1/2"D by 8"W, so it has just over half of the cross-sectional area called for in the Dometic manuals.

What I'm trying to plan is replacing my ACs with newer and quieter units, and tying both into the duct work. I may have to tear down my ceiling panels to do this. Has anyone else ever done something like this? I'm in the gathering info stage.

Tim
Tim,

You might consider that most of the "quiet" in the Whisper Quiet design comes from being able to set the thermostats so the more distant A/C unit does most of the work. When in the living room, you let the bedroom unit do the work. When in the bedroom, you let the living room unit do the work. There's also a little noise reduction from the way the Whisper Quiet A/C units are mounted. But if you're running the unit close to you, most people still describe it as loud.

I don't have any expertise in HVAC design, but I do have the impression that there actually may be some expertise needed to make the system work well. If you're able to get good results and can document your mod, I'm sure others will be interested in following you.
 

StrongJava

Well-known member
Hi Dan,

I'm going to engage my cousin who has done industrial level HVAC throughout his adult life. And anyone else who wants to chime in. As you know, I'm not afraid to dig in and work mods! I do agree though that I want to be totally confident before tearing things out.

From reading and first-hand experience visiting friends in newer Landmarks, the new systems are considerably quieter, and I think it is due to three things: 1) The AC is not protruding into the coach (mounting), 2) running the unit furthest away, 3) insulation.

I'm less sure about the last one, but it is a little bit logical. Since our bedroom unit isn't ducted, we need to use a floor fan when trying to run that unit, which is just about as loud as the AC. And even then, we have to run the AC non-stop regardless. There is really no cycling in any ambient temps above 85°. I'm told by some others they do get cycling.

I still have a lot of research.

Tim
Tim,

You might consider that most of the "quiet" in the Whisper Quiet design comes from being able to set the thermostats so the more distant A/C unit does most of the work. When in the living room, you let the bedroom unit do the work. When in the bedroom, you let the living room unit do the work. There's also a little noise reduction from the way the Whisper Quiet A/C units are mounted. But if you're running the unit close to you, most people still describe it as loud.

I don't have any expertise in HVAC design, but I do have the impression that there actually may be some expertise needed to make the system work well. If you're able to get good results and can document your mod, I'm sure others will be interested in following you.
 

Gary521

Well-known member
StrongJava, do not use duct tape. Use foil furnace tape. Duct tape is not used for ducts anymore and maybe never was used.

Some newer models do not have a common supply between the bedroom and the living room AC's, I know mine does not. What you are trying to accomplish may be not doable.
 

StrongJava

Well-known member
Hi Gary,

Thanks for pointing me towards the proper nomenclature. I suspected duct tape wasn't going to be what I really wanted, and was going to visit Lowe's and look at the HVAC tape options.

I only have one unit that is currently ducted, so I know the vents are all associated with that. What I don't know is if the O/DS duct run, that has a vent in the bathroom, extends into the bedroom. If it does, then I can add a vent there and possibly tie it into a forward AC. If not, then I know I'd have to modify the ductwork.

I just got off the phone with my cousin who suggested the first thing I do is get measurements across the coils. So, I'm going to start with that and sealing the vents better. He also suggested that one of the first mods should be to add a couple of vents along the run.

Tim

StrongJava, do not use duct tape. Use foil furnace tape. Duct tape is not used for ducts anymore and maybe never was used.

Some newer models do not have a common supply between the bedroom and the living room AC's, I know mine does not. What you are trying to accomplish may be not doable.
 

mikeandconnie

Well-known member
Sorry Folks I have to vent....I just came from my neighbors first time owner, 2017 Big Horn. I can't believe there is no AC flow coming out of their ducts. They told me they where told this is how it was designed to work. Since I have to leave tonight, I inform them about the Owner forum. I ask every one please help them.

This thread has been around long enough that no new Heartland Owner should have ducts problems. These systems should not have to be modify to work properly. Heartland I hope you are listening and will correct this problem.

Proud to be a Heartland Owner, disappointed in this.

Thanks
 

danemayer

Well-known member
Sorry Folks I have to vent....I just came from my neighbors first time owner, 2017 Big Horn. I can't believe there is no AC flow coming out of their ducts. They told me they where told this is how it was designed to work. Since I have to leave tonight, I inform them about the Owner forum. I ask every one please help them.

This thread has been around long enough that no new Heartland Owner should have ducts problems. These systems should not have to be modify to work properly. Heartland I hope you are listening and will correct this problem.

Proud to be a Heartland Owner, disappointed in this.

Thanks
If there's literally "no AC flow", maybe the factory put the filters on the output side, instead of the return side.
 

SNOKING

Well-known member
They may have a trailer where they failed to block off the ends of the runs. Chris
 
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tessa

Active Member
following the thread- has anyone looked in the return air to make sure it is sized correctly?
we have 4 reruns in the living room and 2 in the bedroom
going to check out my units to see what I can find and then apply a few of the fixes mentioned
 
I had the same trouble with my brand new 3160 . No air flow into the coach or i should say minimal air flow, after many hours on the phone and this web site .with all the information obtained I started pulling all the vents and to my surprise I found a lot of the Styrofoam missing in the duct work after replacing what I could using aluminium tape Better but not great . I got up on the roof to replace the fan with a fantastic fan and low and behold there was the problem the air supply side of the system ran from the front ac all the way to the back wrapping around the fan with a smaller open square piece of frame connecting back into the return side of the system. so what was happening was just a big loop from the feed side right straight back into the return limiting the pressure to force air into the coach simple fix I just blocked the opening on the piece of channel .now all is well for me.
 
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