Bedroom Cold on Furnace Heat

[AirDFW]

Is it normal for the bedroom in our 2-zone Airstream 27FB to be noticeably colder than the rest of the trailer while running on furnace heat? We noticed that the dining end of the trailer is very warm while the bedroom end can be as much as 5deg colder. Closing the first curtain door before the bathroom hells moderately. In all situations under the dining table is downright hot.

The three bedroom ducts (under wardrobe, in bathroom, and on left side floor of bedroom) DO operate. They just seem much lower airflow than the others. In particular the bedroom and bathroom vents are lower airflow.

Thoughts?

For reference, we have a new 2-zone model with dual A/C. This means that our furnace is only connected to the second zone. But I believe the zoning is NOT relevant for the furnace and only matters for heat pump and A/C functions (which are not in use or the topic of discussion here).

Thanks all! Not sure if a design issue or something to do with impinged ducting in our unit.

[OTRA15]

Welcome to the forum! Have you tried raising the stat's set temp for the bedroom zone up all the way? What Temp have you set it for?

That zone has a hidden remote temperature sensor which may be getting too hot because it is located close to the fridge or some other heat source, I seem to recall from other threads here. You can go to the search function above right, and use the second box in the drop down menu. The Google search results for "remote temp sensor" are here:

https://cse.google.com/cse?cx=011403...sor&gsc.page=1

Any helpful threads?

What model year is your unit, and which exact model please, as the remote temp sensors are located differently in each model/floor plan.

Good luck!

Peter

PS you may also need to do a hard reboot of the Dometic stat, a common necessity for the 2 zone Dometic stats. Check the Dometic manual which came with the AS paperwork. The process is fairly straight forward involving a coordinated pushing of some of the stat buttons. Before doing this, you could also do a basic reset of the trailer's electric by unplugging from shore power, putting the battery Use/Store switch in the Store position. Then plug back in to shore power, and go to Use on the switch -- the stat may work without a hard reboot. Some folks also have had luck just turning the stat on and off 5-10 times in a row.

[Naper]

What you have is normal. The ducts closes to the furnace will have more air flow. to correct this you can change the vent grill closest to the furnace with one that can be closed off.

[dznf0g]

There's a thread (very old) for a mod for that. It involves adding a duct to the BR and closing off one for the living room (in my model.). Jammer is the author and originator, and I tagged on. I'll see if I can find it.

[dznf0g]

Here it is:

http://www.airforums.com/forums/f427...ack-71852.html

Mad a HUGE difference. They should be built this way.

[OTRA15]

Great link Rich.

Peter

[cabinetmaker]

Get a small portable fan and move the air around some. Direct air from warm areas to cold. Also, try running the a/c fans...make sure a/c is not on or set really low so it won't come on and just put the a/c fans (not on auto) on and that will help. Hot air rises so it will get pushed into the returns and out the a/c vents.

[dkottum]

Generally speaking, I like the living room to be the warmest because that is where we spend our time except sleeping. The zone controls have nothing to do with the furnace.

We use the Airstream all winter in NM, CA, and AZ and most of the time have full hookups. So we use three heat sources, a Dyson space heater, an electric blanket with individual controls on the bed, and the furnace is set a few degrees lower than the Dyson so it is only a backup.

If no external electric, the furnace still does a decent job at a low setting overnight, and we use extra blankets as needed for comfort.

[TomKirk]

Years ago, I had the same problem.

I have a '77; 31 ft, center bath, rear bedroom. No matter what I tried, the bedroom was always cold.

My Suburban furnace (under the galley sink), has two outlets (on the furnace housing) pointing forward into the living room. I blocked one of the outlets (difficult to get to, but a simple fix). Success!! More hot air was forced into the bedroom and bathroom.

Suburban makes block-off plates. I got mine @ Evergreen RV in Seattle.

What year is your AS??

Tom

[tot2learn]

AirDFW, we have the same setup as you and can attest to having the heat distribution that you describe. Bedroom is usually much colder, under the dinette where the kids sleep is much hotter.

Perhaps some vent modifications would help circulate the air more evenly, but it's to be expected that the vent closest to the furnace would pump out a larger volume of air.

[dames7]

Same problem, had AS dealer look at it and it's the way AS runs the duck work. It' not a true force air like in your home.

I did put Duct Tape inside the vents to cover half to force the air to the vents I wanted more air to flow and its works, also turn on the AC fan works quite well.

[Two Peas]

We have the same problem - I'm not sure why AS doesn't have dampers on the grills, unless someone else knows.... I'm going out to look for some that will fit - but in the meantime a little heavy duty aluminum foil is helping.

[ghaynes755]

Pulled the grate on one of the two front vents and put aluminum foil inside. Helps even it out. Be careful. Don't block both off. If there isn't enough airflow then the furnace overtemp sensor may trip.

[dznf0g]

Guys, just blocking a vent without regard to required furnace air flow is NOT a good idea. See your install manual for minimum output opening area!

[AirDFW]

Originally Posted by dames7

Same problem, had AS dealer look at it and it's the way AS runs the duck work. It' not a true force air like in your home.

I did put Duct Tape inside the vents to cover half to force the air to the vents I wanted more air to flow and its works, also turn on the AC fan works quite well.

Interesting idea to run the AC fan(s). So does that only recirculate internal air vs. pump in outside 20deg ambient air? Ok to violate the cold weather rule for those units if running fan only?

Spoke with Randy at North Dallas RV and have a warranty appointment set for tomorrow. Will advise here if he finds anything. He commented that many late model AS have a smaller diameter duct to the rear vents 2in vs 4in but that he'd snoop around and look for trouble anyway.

[Roadhoop]

25FC RB, same issue. The vents do rotate to provide directional control. I made sure the bedroom and hallway vents pointed into the bedroom. Also have a small fan (plugs into USB in bedroom) to distribute air. I too like the bedroom cooler and moderately happy with where we are atm. But wish we had better control.

[Ktholin]

We have noticed the same issue in our 25' FB Flying Cloud. Does anyone know if there are aftermarket vents available that can be open or closed to adjust for heat flow to the bedroom?

[dkottum]

The reason for open, non-regulating vents on the Airstream is safety, to keep sufficient air moving over the combustion chamber so it does not overheat. Adding additional or larger ducting is fine, that maintains enough air flow. Closing off or restricting existing ducting is risky.

[dznf0g]

What Doug said. Again, check the installation manual for your furnace. Mine requires 48 Sq in total duct opening. That's four 4" ducts. Just blocking one will result in higher Temps in the other 3. The flexible duct has its limits as does the furnace itself. That's why I went to the trouble to run and additional duct to the rear before shuttering one of the front ducts. The manuals are clear and firm on this point.

[h2ocoolerman]

The front temp sensor is on the left side of the front TV. It's protected by a plastic grill like cover.


Sent from my iPad using Airstream Forums