Not enough hot air to bedroom

[bobnelms]

Hi all,

I have a 37 foot, 2016 Keystone Cougar 5th wheel -- front bedroom. The furnace throws out plenty of hot air to the coach, but very little air comes out of the bathroom or bedroom vents -- and it's cold up there.

I don't mind that at night, but it's uncomfortable during the day.

Is this common?

Thanks

[Roscommon48]

you can try covering the vents in the living room at night; this would be the easiest.


next, it would seem to be, would be to go on the bottom or your rig and try to figure out if there is/are blockages.


good luck

[slow]

I had a similar issue with poor bedroom heat (not bath since in rear in our FW near the furnace). I resolved it by taping the holes at the end of the run of the rectangular underfloor duct (poor workmanship) and replacing the flexible conduit from the underfloor duct to the bedroom register with solid wall aluminum round ducting. The ribbed flexible ducting is very restrictive to air flow. The improvement was so significant, I had to add a floor register in the bedroom with a damper to allow control of the air flow.

[ChuckS]

Since your RV is 3 years old if it HAD good airflow out of furnace registers and now doesn’t Id be looking at the furnace duct tubing under the floor from heater plenum toward low flow registers...sounds like a duct line has come off or has a hole in it.. or something has fallen on it blocking airflow.

[mtofell]

Mine really doesn't put out any heat but since I don't usually dry camp in winter at all I just use an electric heater, if needed. I should have taken it back to the dealer while it was under warranty but didn't get around to it. Someday I'll tear into it to see if the duct is unhooked or blocked. Thankfully, the A/C blows plenty up the bedroom which is more important for my usage.

[bobnelms]

Originally Posted by slow

I had a similar issue with poor bedroom heat (not bath since in rear in our FW near the furnace). I resolved it by taping the holes at the end of the run of the rectangular underfloor duct (poor workmanship) and replacing the flexible conduit from the underfloor duct to the bedroom register with solid wall aluminum round ducting. The ribbed flexible ducting is very restrictive to air flow. The improvement was so significant, I had to add a floor register in the bedroom with a damper to allow control of the air flow.

This is interesting. I'll try this when I get home. When I looked at the furnace ducting, the flexible ducting to the main cabin was a large diameter -- and the ducting to the bed and bathrooms was much smaller. Was that the case with yours also?

[slow]

My main run is rectangular smooth aluminum. The holes were at the end of the main run at the point it transitions to a round flexible duct. The flexible duct then made a “s” turn which I changed to a gradual “L” with aluminum smooth wall duct tubing and a new floor register duct.

[JRTJH]

Keep in mind that there are "two interacting heat systems" in any Keystone RV. The first is the one you're addressing here: Air blown from the furnace to the floor registers to heat the main cabin...

Interlaced with that heating system is the "polar package/Arctic package" that heats the basement to prevent plumbing freeze-ups... The heat that's NOT delivered to the registers is not actually "lost"... rather it's used to keep the belly area warm... When you "think the meandering 15' duct" is the result of poor workmanship at the factory, also consider that the "meandering 15' duct run" goes past two holding tanks and adjacent to "belly fresh water pipes" as well....

While there is some concern with heat distribution from the furnace to the far ends of the trailer, and there should be heat delivered at all the registers, if you "rework the belly ducting" to eliminate all that meandering and insulate the ducting to prevent heat loss below the floor, you may be "self defeating your cold weather capability".....

[bobnelms]

Originally Posted by JRTJH

Keep in mind that there are "two interacting heat systems" in any Keystone RV. The first is the one you're addressing here: Air blown from the furnace to the floor registers to heat the main cabin...

Interlaced with that heating system is the "polar package/Arctic package" that heats the basement to prevent plumbing freeze-ups... The heat that's NOT delivered to the registers is not actually "lost"... rather it's used to keep the belly area warm... When you "think the meandering 15' duct" is the result of poor workmanship at the factory, also consider that the "meandering 15' duct run" goes past two holding tanks and adjacent to "belly fresh water pipes" as well....

While there is some concern with heat distribution from the furnace to the far ends of the trailer, and there should be heat delivered at all the registers, if you "rework the belly ducting" to eliminate all that meandering and insulate the ducting to prevent heat loss below the floor, you may be "self defeating your cold weather capability".....

Excellent point! Once again, this forum comes through for me!

I do wish, however, that Keystone would have increased the diameter of the ducting that went to the bed and bathrooms (forward bedroom). If I dampen the registers in the main cabin to get more air into the bedroom, the main cabin will start suffering.

[JRTJH]

Originally Posted by bobnelms

Excellent point! Once again, this forum comes through for me!

I do wish, however, that Keystone would have increased the diameter of the ducting that went to the bed and bathrooms (forward bedroom). If I dampen the registers in the main cabin to get more air into the bedroom, the main cabin will start suffering.

All of our trailers, from a 93 Holiday Rambler to the current Cougar that have been longer than 30' have had airflow issues with the extreme end run registers. There's just no "easy way to run a 8" duct 30 feet from the rear mounted furnace to a front room register when that 8" duct needs to be fitted in a 6" space.... Houdini might have been able to figure it out, but RV manufacturers, so far, haven't....

That said, our fifth wheel has virtually ZERO airflow at the bedroom register. But, with the doors open and with the bedroom being elevated above the main floor, there's enough "heat rise" occurring to keep the bedroom and bath warm, even in cold temps. We prefer the bedroom a bit cooler anyway, so it works for us. I'd check to make sure the ducting is connected, not crushed and is routed somewhat properly, but, at least for me, I think, before making any modifications to the trailer ducting, I'd use a small quartz heater if supplemental heat is needed on cold nights and "make do" in moderate weather.

Now, if I was full timing or "found it mandatory to have heat" then I'd look into a permanently mounted wall space heater for the bedroom and hardwire it next to an available plug.

[pdaniel]

Originally Posted by bobnelms

Hi all,

I have a 37 foot, 2016 Keystone Cougar 5th wheel -- front bedroom. The furnace throws out plenty of hot air to the coach, but very little air comes out of the bathroom or bedroom vents -- and it's cold up there.

I don't mind that at night, but it's uncomfortable during the day.

Is this common?

Thanks

I had a 2017 Cougar “X-lite” 30RLI. I experienced the same issue with that trailer-little air in the bedroom and not much more in the living area.
I attempted to get more air by closing some of the flow in the bathroom. No success. I did seal the ducting outlets on the furnace itself and there was some, not much, improvement. Then to add insult to injury the living area had one, only one, heat register.
I discovered in the process of upgrading to a 5th wheel that Keystone, and possibly others, use a plenum and tap off of the plenum for the individual outlets and when you get to the end of the plenum, or, the air has been directed to the plenum there isn’t much volume of air left.
So, in my research I bought a 5th wheel that has dedicated ducting to each outlet including the belly and basement. The furnace is the same size as the furnace in my former Cougar yet there is sufficient volume to heat the entire coach and my furnace does not run constantly in the winter as the Cougar did. And my new RV has three registers in the living area and none, not one, come up through the floor. The bedroom has plenty of heat that most nights I do not need to run a space heater as I did in the Cougar. This new 5th wheel is 35 feet inside with 3 slides with large and many windows, yet, stays warmer than the Cougar with the same furnace and Keystone’s four season insulation.

What Keystone and others do with the plenum system is just introduce a poor, very poor, design. And that is disturbing given the money we spend on these RVs.

[Jerry Bies]

2019 3711fl had poor airflow also. It had poor airflow to rear main bath and bedroom area. The ducting was not engineered correctly. The main home run of duct was recetangle 3” x 10” which has plenty of flow when duct was put to bedroom/bath run was only a 3” flex tube. Do you math square inches of rectangle duct is 30 square inches getting reduced down to 3” (radius x3.14 )tube which then goes back up to 3x 10 duct again. A big drop in flow. The way I corrected mine was I removed the 3” duct and installed a double 8” double 90 degree elbow. Works good now has no flow restriction. I also bought new heat grates for the floor that can be throttled back some to balance the air flow.

[thefulminator]

I'm not sure of the configuration of your furnace but thought I would pass along an issue we had a couple years ago to see if it would help explain your problem. Our 2013 Outback 250RS the furnace is under the sofa and feeds all the registers with flexible ducts. All of the ports on the furnace are not used and a couple of them have caps to seal them off.

The caps and ducts slide into a groove around the perimeter of the circular openings in the furnace and spin to lock. Due to vibration during travel, one of the caps rotated and fell out. We were getting plenty of heat in the living area around the sofa but not much to the far end of the trailer. Once I found the open port, I put a slight bend into the cap with a pair of pliers so that it had enough tension not to rotate and reinstalled it. We haven't had any problem since then.

[sonofcy]

Originally Posted by bobnelms

Hi all,

I have a 37 foot, 2016 Keystone Cougar 5th wheel -- front bedroom. The furnace throws out plenty of hot air to the coach, but very little air comes out of the bathroom or bedroom vents -- and it's cold up there.

I don't mind that at night, but it's uncomfortable during the day.

Is this common?

Thanks

Use a flashlight and mirror or get a borescope to see if there is a blockage. If not, try closing some vents or install a booster fan where needed. Since my flannel sheets keep me warm I set the night time temp to 64.

[Woodz71]

I’m glad I searched this topic, this has helped me out tremendously. I have an ‘18 Keystone Sprinter 3531FWDEN which has a front bedroom and the heat pumping into this space is not nearly enough to even keep it comfortable. We are entertaining the thought of a space heater to combat this issue (though it won’t be used but maybe 3 weeks out of the year being we in FL)

I’ll try covering the registers in the living area at night to see if it forces air to the bedroom. If not, I’ll be on Amazon ordering a ceramic space heater.

[JRTJH]

Originally Posted by Woodz71

I’m glad I searched this topic, this has helped me out tremendously. I have an ‘18 Keystone Sprinter 3531FWDEN which has a front bedroom and the heat pumping into this space is not nearly enough to even keep it comfortable. We are entertaining the thought of a space heater to combat this issue (though it won’t be used but maybe 3 weeks out of the year being we in FL)

I’ll try covering the registers in the living area at night to see if it forces air to the bedroom. If not, I’ll be on Amazon ordering a ceramic space heater.

Your solution is one that many of us have used. I wonder if the trend toward fireplaces being installed in bedrooms in larger fifth wheels might be "the manufacturer's solving the problem by installing an electric heater in the bedroom" (primarily for supplemental heat under the guise of ambiance)

[flybouy]

In rereading this post it seems obvious to me that the rv industry isn't considering the increasing numbers of people using large campers as primary residencies in their designs.

Environmental systems in residential applications are engineered by licensed professionals to deliver balanced air flow and exchanges to meet codes. In the RV industry, at least in the "non luxury" segment it appears to be an "afterthought" of with a "make it fit" priority. The RV industry is not governed by BOCA or SBCCI codes as by definition an RV is not considered a permanent residence.

Looks like the "industry" keeps moving closer to the "full time" thinking with the "Arctic packages, residential refrigerators, larger tanks, etc. Sounds like they need to address the HVAC systems to make them a full "4 season" home on wheels.

[JRTJH]

There is a fine line between mobile homes (manufactured housing intended as full time living quarters) and recreational vehicles (smaller manufactured housing intended for part time recreational use). Several regulatory agencies through the last 10 or 15 years have attempted to require RV's to meet manufactured home standards. Every attempt has been met with resistance and has failed. Right now, RV's are "justified for production and use" as smaller than some arbitrary square footage, classified as "non-permanent" or "always moveable" because the axles are not "detachable"...

I'm sure there is much, MUCH more to the classification differences than just the above, but the "gist" is that every time there has been a move to "bring RV manufacturing under the mobile home umbrella" it has failed. I don't expect that it's going to be done in the foreseeable future, there are way too many "bigger fish to catch/fry" in our growing economy.

[Woodz71]

In my world, my RV is just that... a mobile structure intended for temporary housing based on recreational usage. If I need to supplement heat I’m ok with it. We do have a fireplace/heater in the living area.

I do agree with your assessment of the fireplace installed in bedrooms and living rooms to supplement the lack of poor design, construction and/or equipment to make up the volume of heat needed, especially in the entry and mid level FWs. I have also noticed that my new mobile man cave (or doghouse, depending if you’re asking me or her...) is quite drafty and I’m wondering if this has an affect on the heat in my bedroom 🤔

[trucker LOU]

Hi All, The hot air flow will improve as we approach the upcoming election,---