Heat ducting in Gateway 3650BH

GWRam

Well-known member
While I have my basement walls down for some remod work I was looking at how the heater flex duct comes out of the underbelly through the floor and up to the heater vent in the master bathroom. The hottest room in the camper and the one with the most air flow. Attached to the same box at the heater vent is another flex duct which goes back down into the under belly. I don't know if this is to get warm air to the enclosed belly or to go toward the master bedroom heater vent. Almost no flow at all in master and always cool air what do come through.

I can't figure how the air gets to the master vent. There are no vertical walls over 2 1/2in wide for ducting to go up through. The ceiling of the basement/ floor of the master and bath are 2 1/2 in thick so nowhere for ducting and its not hanging from the basement ceiling from the bathroom vent to the master vent like the Heartland rep said it should be. I haven't been able to find any drawings or design plans showing how the ducts should be run. Anyone seen or know how/where the ducts should be run?

Any input will be appreciated.

Dave
 

Cjackg

Well-known member
...watching this with interest as my Cyclone, and a friends have the very same problem with all the hot air blasting into the m-Bath and very little in the other rooms. Sure would like to see some tips before I start trying to fix this.
 

sengli

Well-known member
The heater is usually right under the bathrooms, so its the shortest run, therefor it gets the most heat. On my big horn, there is no baffling in any of the runs, so what ever is closest gets the best, and most air flow. I have been to the factory 6 times for the different tours and seen these units being built, honestly they run the ducts wherever they can squeeze them from the looks of what I've seen. That being said, you can modify them to your liking if you can get to them. Others on here have installed baffling, and rugulated register covers to regulate the flow of heated air elsewhere as needed.
 

GWRam

Well-known member
The heater is usually right under the bathrooms, so its the shortest run, therefor it gets the most heat. On my big horn, there is no baffling in any of the runs, so what ever is closest gets the best, and most air flow. I have been to the factory 6 times for the different tours and seen these units being built, honestly they run the ducts wherever they can squeeze them from the looks of what I've seen. That being said, you can modify them to your liking if you can get to them. Others on here have installed baffling, and rugulated register covers to regulate the flow of heated air elsewhere as needed.

Thanks for the reply. What you said about how the runs are placed is part of what confuses me on our unit. The bathroom vent in our unit is the next to last on a run, if they are on the same run, or as far as distance goes the only vent further away is the master floor vent. The bunk house and the main living space are both closer to the furnace which is behind the rear axle (on door side) of the unit. When on your factory tours did you notice if there were multiple runs? Such as I have 4 vents, where there 4 runs or where they tied together such as one run from heater and then spider out from there. The master and bunk house have almost no air flow. The main living space vent has good airfow but is half the temp or less of the bathroom vent which is twice as far away from the heater as the living space vent.
 

sengli

Well-known member
Well ya know, yours sounds like it is equipped differently. Here is a photo of my duct work. In the forfront of photo you see the dangling run used to put heat in the underbelly. There are only so many outputs from the heaters manifold, so yes they might have split your runs.

Sometimes these flexible runs can get pinched as they are run thru the chassis. If your air flow is good, but much cooler...could be a number of reasons for that. Torn run, split into multiple ouputs?
 

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GWRam

Well-known member
It looks like you have at least three maybe four runs coming off your heater. That gives me some idea what to be looking for. Thanks
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
I can't say for sure, but since the gateway does not have a drop frame, the ducting may not be like a Bighorn. In my ElkRidge, there is no flexible ductwork, except going from the lower level to the upper level. Everything else is rectangular metal duct running in a line under the flooring from back to front of the unit. In our case the heater is between the kitchen and entertainment slides, so living area gets most heat. Bedroom gets least since its farther from furnace. But it is in line with bathroom, and bathroom gets much more than bedroom. There is no way to check the ductwork attachment at the unit, I think all the hot air goes into the one metal duct. We have added regulating vent covers. We do not close any, but have some closed a little more than others to balance the heating.


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GWRam

Well-known member
This will be an extended project I can see that now.

Pulled cabinet apart and found that I have 4 flexible runs coming off the back and top of furnace box. Like on the photo by sengli. Only all four ducts are the same size diameter.

The flex duct attach to the furnace is a heavy silver fabric. I guess because of the temp at the furnace.

The one coming out of the top of furnace make an immediate 180* turn cutting down airflow.

One of the three coming off the back is jammed through a hole in the floor alongside the vent stack. This duct is twisted and pinched reducing airflow by at least half.

I can see that to address this properly I will have to find a location to pull the bottom of the camper and spend some time getting things straightened out...

Have to be worked on after next trip..

Thanks for the replies
Dave



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TravelTiger

Founding Texas-West Chapter Leaders-Retired
This will be an extended project I can see that now.

Pulled cabinet apart and found that I have 4 flexible runs coming off the back and top of furnace box. Like on the photo by sengli. Only all four ducts are the same size diameter.

The flex duct attach to the furnace is a heavy silver fabric. I guess because of the temp at the furnace.

The one coming out of the top of furnace make an immediate 180* turn cutting down airflow.

One of the three coming off the back is jammed through a hole in the floor alongside the vent stack. This duct is twisted and pinched reducing airflow by at least half.

I can see that to address this properly I will have to find a location to pull the bottom of the camper and spend some time getting things straightened out...

Have to be worked on after next trip..

Thanks for the replies
Dave



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Take pics and document your work, as others may benefit from your exploration!


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Cjackg

Well-known member
I just completed tuning up the heating air flow in my Cyclone 3110 and the result was a much more even flow from most of the registers. The picture below shows the furnace which I was able to access from the closet near the 3110 entry door. I was also able to access some of the duct pipes from the basement area near the UDC.

The 4" pipe on the top of the furnace goes direct to the bathroom and is only a few feet long. I installed a small aluminum baffle in the furnace connection for this pipe to reduce the flow about 50%.
The upper left side pipe runs to the bedroom and I rerouted and shortened this pipe to eliminate some curves and kinks. The small pipe on the top seems to run to the garage and I removed several feet and some kinks but it seemed to have little effect on the garage heat as it still blows very cool air through that register.

The other 2 (lower) pipes on the side of the furnace connect into fittings on the floor of the basement possibly a Plenum arrangement that feeds the living room ducts. They are partially pinched by wires and plumbing but not easily improved so I left them alone.

The net effect of the changes I made was more even warm air flow to both the living room and bedroom and reduced airflow in the bathroom. After running the heat for several hours the heat distribution seems much more even and I am satisfied with it for now.

//heartlandowners.org/attachment.php?attachmentid=33135&d=1416089285
 

Cjackg

Well-known member
Isn't that small duct for heating the under belly?
I have heard that before... but, a pipe that same size runs into my Garage heat outlet at the back so I assume it came direct from the furnace...
If I get around to opening up the underside I can pin it down.
 
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