ATF: Bighorn - Whisper Quiet ducting design issue
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mikeandconnie
Well-known member
As I posted earlier on this thread my AC are blowing and cooling wonderfully after some modifications. I just added the adjustable vents and it's freezing in my rig in Tampa, Fla, But now my front AC is freezing up I think" Well the thermostat Inside temp is reading 32 deg and the compressor is not kicking in. I did swap thermostat and it's the same. I may have to move back the back thermostat or cut back on the airflow. However my DW like it freezing. I guess I will come up with something. Can someone confirm that when your thermostat inside temp read 32 degree the 32 degree temperature switch has been made?
SNOKING
Well-known member
Scott at CS said the 32 temp is a frost condition. Seal the four extra mount holes and seal up any cracks in the plenum below the unit with HVAC tape. Chris
NHCelt
Well-known member
The ducts run front to back the length of thd rig. There are 4 foam blocks, one for each end of run just fore/aft of the front /rearmost vents. They have been found in many places and are just a friction fit, so you should be able to move them easily... But they have to be sealed afterwards. Not all of them seal properly.
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I will check each end . Thanks, appreciate the help.
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For Bighorn 3760 EL owners. I spent some time looking at my rig with a flashlight and a cell phone camera to look down the duct work.
I haven't had a good chance to test the ac on a really hot day yet but on a medium hot day the units seemed to work harder than they should.
Its a two AC trailer.
I found the 6 ducts on the inlet side are connected to one long shaft, with seals at the two ends of the trailer. Both seals were there but they didn't seem to fit very tight.
I noticed one vent stack which went thru the duct in one area, but I couldn't get a close look at it. There were also small diverters where the ac connects.
The outlet sides were two separate ducts. This makes some sense since this rig has a shower and a bathroom vent that prevent a long straight duct run on the outlet side. Two bedroom vents and the bath are on one ac and four living room vents are on the other AC,
To summarize the two AC units share air intakes but have separate outlets.
I haven't decided what to do yet, but I think I am going to put in additional seals at the 6 ends of the runs.
I haven't had a good chance to test the ac on a really hot day yet but on a medium hot day the units seemed to work harder than they should.
Its a two AC trailer.
I found the 6 ducts on the inlet side are connected to one long shaft, with seals at the two ends of the trailer. Both seals were there but they didn't seem to fit very tight.
I noticed one vent stack which went thru the duct in one area, but I couldn't get a close look at it. There were also small diverters where the ac connects.
The outlet sides were two separate ducts. This makes some sense since this rig has a shower and a bathroom vent that prevent a long straight duct run on the outlet side. Two bedroom vents and the bath are on one ac and four living room vents are on the other AC,
To summarize the two AC units share air intakes but have separate outlets.
I haven't decided what to do yet, but I think I am going to put in additional seals at the 6 ends of the runs.
TravelTiger
Founding Texas-West Chapter Leaders-Retired
This is basically what we found as well, I closed off the duct runs just past the last vents at each end of the downstairs unit and each end of the upstairs unit, essentially making them two separate systems. This seems to have helped a lot.
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billvenohr
Member
Just purchased 2017 Bighorn 3760EL and we have our bedroom air conditioner raining water down on us when it shuts down. Our rear A/C will shutdown with an error code if we put the temperature too low e.g.72F. Big problem with summertime heat. After threatening dealership (Windish) and getting a call from Heartland, they want to take unit back to Indiana to fix. Said its a Dometic issue but they need to stand behind their unit. Supposedly they are meeting with Dometic tomorrow and will have a solution --then goes to engineers. In meantime we live in marginal A/C and will have to take time off from work to take to Indiana. Any others with this situation? Any ideas? Leaving is a hardship but so is A/C.
SNOKING
Well-known member
Seal these holes.
There are four of them open to the plenum. Also on both of my units the foam cover inside the units had broken pieces that I had to glue up. Sounds like they declared you the trial horse to resolve a wide we spread problem. Tell them to just work with a unit off the production line and then fix all of the rest of us.
There are four of them open to the plenum. Also on both of my units the foam cover inside the units had broken pieces that I had to glue up. Sounds like they declared you the trial horse to resolve a wide we spread problem. Tell them to just work with a unit off the production line and then fix all of the rest of us.
NHCelt
Well-known member
That is an interesting response. My money says it's a Heartland issue...please keep us posted. I am going to say leaky duct work causing partial or total freezeups and then overloading the drip tray... What is the error code?
billvenohr
Member
Error code was E-1. We were able to reset by turning all power off for 20 minutes then resetting the thermostat. Keeping it at 76F has kept it working. Not sure if ducting issue, but Heartland says they only figured out roughly two weeks ago that they had a big problem. The amount of water that dripped out was one time probably a quart.
SNOKING
Well-known member
It will be interesting to hear their solution to a lousy install or equipment, that everyone is getting. Raining on the bed is not what a brand new 6 or 7 week old 2017 trailer should be doing(my case).
Two 15,000 BTU units should be able to turn the average 5th wheel to a ice box fairly well. When they resolve the freeze up and rain problem, they then need to address the ducting/performance issues. I blocked off the duct on the supply side between the two. Bedroom seemed to really put out cold air in a short test. However three supply and only two return vents seems out of balance. Chris
Two 15,000 BTU units should be able to turn the average 5th wheel to a ice box fairly well. When they resolve the freeze up and rain problem, they then need to address the ducting/performance issues. I blocked off the duct on the supply side between the two. Bedroom seemed to really put out cold air in a short test. However three supply and only two return vents seems out of balance. Chris
TravelTiger
Founding Texas-West Chapter Leaders-Retired
Yes please keep us informed, if there's something to be fixed we all need to know about it... Even though I think ours was built with an older model AC unit on the roof.
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billvenohr
Member
Lakewood actually
- - - Updated - - -
I talked with Jim Fenner, Director of Customer Service. He said they (which I think means Dometic and Heartland) are putting a coach through some fixes with tests in their climate control booth. We hit 95F today--one air conditioner cannot keep up!
- - - Updated - - -
I talked with Jim Fenner, Director of Customer Service. He said they (which I think means Dometic and Heartland) are putting a coach through some fixes with tests in their climate control booth. We hit 95F today--one air conditioner cannot keep up!
We just got our BigHorn and it appears that one side of the vents for the AC are for return air and the other side blows air out. It looks like their is a foam filter in the return side. If I'm wrong, then mine is screwed up. Also, calling this AC whisper quiet is hardly accurate - mine are noisy.
nander
Texas North Chapter Leaders-retired
We have this same issue with the living room unit. The rig is about 6 weeks old. We had the E1 code and water leaking. The unit would not put out any cool air. We had a mobile tech and they spoke with dometic. He put in a new board. It still 'freezes up', but no more water dripping. I turn it off when it makes a loud noise.
Based on others who have commented, we took the roof cover off and tightened down the screws in order to get 'compression' in the gasket. We have not had a chance to run it yet. The bedroom AC puts out a lot more air than the main unit. Even with both running, they have a hard time with 100 degree heat.
Hopefully, Heartland & Dometic can come up with a solution. At this point, I would go to Indiana to get it fixed. That is faster than the 2 months my dealer wants for a repair.
danemayer
Well-known member
The return side is supposed to have filters. Feel the airflow to see which side is blowing air and which side is the return.
