Ray LeTourneau
Senior Member - Past Moderator
My 3400 has the same vent. It seems redundant as the areas between the joists above that wall are open as well and provide the same thing. A way for air to move between the two spaces. I don't know, it looks impressive though.
creeper
Well-known member
Can't be for heat as the heating system will suck cold air IN from that area and then blow it through the vents inside the camper.
The gap to the holding tanks also allows air to be sucked in from the underbelly. Sucking freezing cold air from these areas lowers the efficiency of the furnace, harder to heat cold air then it is to heat warm air.
Has anyone sealed off the gap that goes to the underbelly?
The gap to the holding tanks also allows air to be sucked in from the underbelly. Sucking freezing cold air from these areas lowers the efficiency of the furnace, harder to heat cold air then it is to heat warm air.
Has anyone sealed off the gap that goes to the underbelly?
Pulltab
Well-known member
You furnace recirculates air but may be pulling from the cargo area. The vent you speak of probably looks like a regular register but nothing connected to the back of it. Allowing air to get to the converter area to help cool is probably its main purpose. I believe it is just assumed that the cargo area will all be heated. Its not that large an area and if you seal it to prevent any heat from getting to it then you will have cold air attacking the floor under your bedroom. So unless you insulate that your not achieving anything. I prefer to have my basement are heated just for the cold air under the bedroom issue. The wall between the living quarters and the basement are nothing but a piece of carpet covered wafer board, no insulation to prevent heat transfer. You could easily insulate all that but for the little gain it would be money wasted in my opinion. 
creeper
Well-known member
That vent makes sense for the summer time. In the winter the best you're going to do in that area is what you have your thermo set at and maybe a few degrees warmer.
I don't understand how heat would get in there? There is no forced air at all. The furnace only draws from that area. The floor to the bedroom is insulated and is still be attached by cold air even if you seal off that little vent.
Drawing air form the underbelly is also not a good idea, but very hard to seal off. Might just put some foil bubble wrap stuff over that. Increasing the efficiency of the funance can only help save money. Pink board and foil may run $25. Over the years it could add greatly to the winter comfort.
Drawing from the storage bay and the underbelly is like leaving a window open, you furnace will heat the place buy work that much harder to maintain that level.
I don't understand how heat would get in there? There is no forced air at all. The furnace only draws from that area. The floor to the bedroom is insulated and is still be attached by cold air even if you seal off that little vent.
Drawing air form the underbelly is also not a good idea, but very hard to seal off. Might just put some foil bubble wrap stuff over that. Increasing the efficiency of the funance can only help save money. Pink board and foil may run $25. Over the years it could add greatly to the winter comfort.
Drawing from the storage bay and the underbelly is like leaving a window open, you furnace will heat the place buy work that much harder to maintain that level.
Pulltab
Well-known member
The furnace does not have a cold air input. it just pulls the air from inside the coach. The basement gets heated by convection, it is not forced like the living area but heat will transfer to the basement.
Sounds like you have yourself convinced on what to do GET R DONE!
Sounds like you have yourself convinced on what to do
GET R DONE! 
linuxkidd
Member
In my Landmark, there is actually a forced air output in the belly area. It comes off of the furnace and moves under the black tank. It dumps in under the tanks.
Not sure if it's the same on all lines, but I'd wager that the Landmarks all have this. ( Look on Heartland's site for 'Heated Basement' or 'Heated underbelly'.
LK
Not sure if it's the same on all lines, but I'd wager that the Landmarks all have this. ( Look on Heartland's site for 'Heated Basement' or 'Heated underbelly'.
LK
creeper
Well-known member
LK,
The Bighorn has the same thing, but the basement is really not heated at all.
Heated underbelly is a stretch and evidenced by many reports of freezing pipes. Here are the problems:
1. The heat vent that goes to the underbelly is a small 1 - 1 1/2" pipe.
2. The vent does not have much force behind it and absolutely has no way of heating the entire underbelly or even the front half.
3. The vent only drops down under the black tank and into the dropped frame area and not into the rear area, which is prone to freeze and no way the heat from the weak vent can get to. Furthermore, why dump heat on the lack and grey tanks only? It should be dumped where the fresh water is.
4. Hear rises, so the heat that is put into the front belly area just rises back up into the area where the heater is located.
5. The fresh water line is uninsulated. It lies on the bottom of the underbelly with only a small foil insulator protecting it.
Solutions for current owners:
1. Extend the vent to get heat on the waste valves and fresh water area or add a second heater to the rear area. I added a Golden rod between the fresh water tanks and the galley tank. The Rod is good for 500 sq feet and is much safer then a light bulb or ceramic heater. I'll let you know how it works in our upcoming sub zero camping trip. Adding more is an option. You can also leaving running during the summer months to remove moisture.
2. Add a second heater to the basement area to make it an actual heated space if heating that space is important to you. For me I'm going to add insulation to the wall between the basement and living area.
3. Insulate your fresh water line.
Solutions for Heartland:
1. Add a vent to the rear underbelly area. The furnace appears to have space to add one more vent. You could drop it down under the fridge and into the rear underbelly.
2. increase the size of the current underbelly vent, extend and split it.
The Bighorn has the same thing, but the basement is really not heated at all.
Heated underbelly is a stretch and evidenced by many reports of freezing pipes. Here are the problems:
1. The heat vent that goes to the underbelly is a small 1 - 1 1/2" pipe.
2. The vent does not have much force behind it and absolutely has no way of heating the entire underbelly or even the front half.
3. The vent only drops down under the black tank and into the dropped frame area and not into the rear area, which is prone to freeze and no way the heat from the weak vent can get to. Furthermore, why dump heat on the lack and grey tanks only? It should be dumped where the fresh water is.
4. Hear rises, so the heat that is put into the front belly area just rises back up into the area where the heater is located.
5. The fresh water line is uninsulated. It lies on the bottom of the underbelly with only a small foil insulator protecting it.
Solutions for current owners:
1. Extend the vent to get heat on the waste valves and fresh water area or add a second heater to the rear area. I added a Golden rod between the fresh water tanks and the galley tank. The Rod is good for 500 sq feet and is much safer then a light bulb or ceramic heater. I'll let you know how it works in our upcoming sub zero camping trip. Adding more is an option. You can also leaving running during the summer months to remove moisture.
2. Add a second heater to the basement area to make it an actual heated space if heating that space is important to you. For me I'm going to add insulation to the wall between the basement and living area.
3. Insulate your fresh water line.
Solutions for Heartland:
1. Add a vent to the rear underbelly area. The furnace appears to have space to add one more vent. You could drop it down under the fridge and into the rear underbelly.
2. increase the size of the current underbelly vent, extend and split it.
Pulltab
Well-known member
Creeper, here was my solution to the problem but I like to tinker. I insulated the entire bottom of my rv with in some places 6" but in others 10" insulation, leaving a 6" space on each side of the tanks, grey, black and water. I then hooked the output hose from the furnace to a lenght of 1-1/4" pvc pipe run the length of the rv. I capped the very end and then where ever I needed heat directed I drilled a 3/4" hole to direct it to each side of the tank. I also used that foam stick insulation and insulated ALL the water lines in my rv even the ones in the basement but especially in the underbelly. I have 2 remote sensors in the underbelly, one by the rear galley tank and one up by the black and water tank. I can monitor them from inside. Usually the underbelly runs about 10-15 degrees lower than inside temp. So if I keep the inside at 70 the underbelly hangs around 55 and cools off a little before the furnace kicks back on.
creeper
Well-known member
Thanks Pulltab. I already put in two remote sensors and insulated the lines.
Putting a length of PVC would be tough, due to slides and heater hoses which are jammed into a small space. That's why I went with the golden rod. It heats to 150 degrees, draws few watts and I can run it 24/7. I'll see how that works. Going to test this week when I get the belly back on. Just finishing up the SeeLevel upgrade.
Putting a length of PVC would be tough, due to slides and heater hoses which are jammed into a small space. That's why I went with the golden rod. It heats to 150 degrees, draws few watts and I can run it 24/7. I'll see how that works. Going to test this week when I get the belly back on. Just finishing up the SeeLevel upgrade.
jmgratz
Original Owners Club Member
Hey Pulltab, Check out this link for Goldenrod. There is a good explanation as to what it is and how it works.
http://www.drytheair.com/xcart/store/catalog/product_16152_36_GoldenRod_Dehumidifier_38_Watts.html
http://www.drytheair.com/xcart/store/catalog/product_16152_36_GoldenRod_Dehumidifier_38_Watts.html
