Winter Use of our T@B

DougH

Brilliant.  I guess you could always put a computer fan on that opening to force warm air into the black tank area mounted in the undersink access panel, and tapped in to the fridge 12V supply.  With a small exhaust port in the bath area, you might be able to leave things buttoned up. 

Tabaz

I I bought a 12v fan from an auto parts store today for that exact purpose. WAY too loud to be practical! The “small exhaust port” is to simply leave the glass door ajar. Will take more readings tonight and report back. The quiet computer fan would be an easy addition. So glad I completed this mod.  It’s opened up a whole new camping experience for me.  No way I would have taken the trailer to a cold location with the possibility of pipe damage.

DougH

That sounds better than drilling a hole.

I bought the one listed below to keep the inverter heat evacuated through a port in the floor when running the inverter in the summer.  It's 2W, 12V, 31dB and 43CFM, but sometimes I have to turn it on twice to get it rotating. But it's gone a couple years in heat and cold and bouncy roads.

https://www.amazon.com/dp/B00N1Y50QQ

Tabaz

Doug - Check out the thread “Noisy Norcold.” I was VERY pleased with the Noctura “Mouse Fart Quite” Fans used in my frig mod. Is this model better?

DougH

Nope.  Same CFM but noisier with lower MTBF.  Adding the Noctura to my Amazon wish list now.  Besides, the brown fan seems somehow more apropos for heating the black tank area. I have some spare thin Baltic Birch to mount it to in that access panel space and will just leave a toggle switch right next to it.  Now how to remember that it's on? 

Tundra57

Sorry have not completed my PDF for my basement mods to my Tab 400. I still have to add the extra insulation to the floor of the trailer under the bed and box in the dump valves. I ran the system with outside temp at 32degrees. Inside on gas only set to 68. The temp inside under the fridge where the water pump is stayed at 70. The area below where the water outlet is inside the basement stayed at 51. This point is close the where the new pipework enters the basement and furthest away from the radiator which is in the middle of the tanks. I also tried towing with same setup at around 33 degrees and cabin set to 58 degrees. Under fridge around 60 cold tank outlet 51.

I plan to box in the dump valves and outlet completely, access with a lift door. It will extend down the frame to where the frame rails slots were. Here I'll bore a couple of holes. A small 12v computer fan in one and the other will act as a return. This will circulate warm air from the basement into that area. I ran out spare wires for a temp probe and the fan to a new fuse and switch  panel under the fridge already. Judging by @Tabaz results it should all work great. I did run wires for heating pads but I doubt I'll need them. My additional pipework and radiator added another gallon of coolant. My diverter valves are only set half way so far so only half the fluid routes thro the basement (this is a rough estimate as the resistance of the new basement is much higher that the bypass loop so the the flow is likely to be way less than half). The valves serve to control the flow down below or shut it off. I did increase the flow to number 3 on the circ pump, mostly to help bleed the system. There is still no noise, but now the coolant level has stabilised I'll drop it back to 2.5 and test again.

Tabaz

Tundra - just a reminder to include an Alde “drain tee” at the lowest location of the new loop. Happy to see you’re also getting excellent results with your take on this mod.

Tundra57

Ah @Tabaz   I did forget that. That will be a job for when I box in the dump valves I think the frame hole is big enough to reach the pipes to cut and fit a drain. Good catch. :-)

DougH

@Tabaz ; The computer fan you recommended came in from Amazon, and I put it in using the existing panel cover. I took some pics looking down through the bath access panel to see if I could see the edge of the black tank from that perspective, but there was too much plumbing in the way. Whether the access panel in the bath was open or closed, there was little resistance to the fan, so the air being blown over the black tank must be going somewhere. There was around 2" of space between the panel cover and the side of the black tank, so the fan would have barely squeezed in on the inside for a cleaner install, but I figured it would have less air resistance and more volume pushing from inside the cabinet. Still, it should help get cabin air into that cavity if I leave that cabinet door cracked.  I'll stick a thermocouple somewhere on the black tank that I can reach, and see if the fan makes much of a difference in the next few months.

Tabaz

Lucky that you have an access panel - I just have an open hole next to the ABS pipe in your photo.  Very nice install!  By reversing the hinges on that door, you can leave it open at night without messing with the shower door.  Doesn't look too bad having the knobs on different sides.

ChanW

@DougH,

and be sure to leave that jug of antifreeze sitting there -- it should help!

DougH

@ChanW ; And it's good that @Tabaz and I have the warming fan pointed in TOWARDS the black tank.  Otherwise if either of our black tanks crack down the side at -25F this season, I wouldn't want the fan evenly splashing all that stuff all over the forward half of the cabin.  Eeewww!

P.S.  Fan only pulls 0.2A.

P.P.S.  I have a thermocouple attached to the side of the black tank eight inches back from where the fan is, and covered by a couple layers of duct tape.  With outside at 40F, turning on cabin heat to 60F barely raised the black tank temperature after a half hour.  So there's lots of thermal mass there and no direct heat source. Turning on the fan raised it 8F in fifteen minutes.  Could be the thermocouple is still to close to the vent fan (it's as far away as my hands would reach), or it could be the fan really helps warm the black tank.  But only subfreezing measurements matter, and only long term tests where the cabin is kept at 60F for many hours or days, so I'll just wait till I get somewhere colder.

ChanW

Oog!¡!

Glad you were thinkin!

DougH said:

@ChanW ; And it's good that @Tabaz and I have the warming fan pointed in TOWARDS the black tank.  Otherwise if either of our black tanks crack down the side at -25F this season, I wouldn't want the fan evenly splashing all that stuff all over the forward half of the cabin.  Eeewww!

jtalarek

i'm afraid I posted this under solo camping but it should have been under Tips.  sorry about the duplication.

I just got a T@B 320-S this summer and have had it on a couple short trips and absolutely love it!  I plan to leave Michigan after the holidays and head south until it seems safe to dewinterize, then head west along US 10 to California.  If temperatures are mild enough in late February/early March, I hope to return by US 20 and then winterize before turning north for home.  I have been checking average high/low temperatures along my route and it looks like average lows can hover right around freezing at night, especially in the mountains.  I get that average means the temps are sometimes lower and I plan to watch the forecasts and vary my route accordingly. 

I have reviewed the past postings, some seemed helpful while others are technically way beyond my talents.  I have tent camped for 30 years and have learned more than I would have imagined about campers but am really feeling like a novice in this area. Following are some of my observations, ideas, questions, and concerns and I would love to get some of your insights based on your wisdom and experience.

1. I plan to leave the water pump hatch and cabinet doors open on cold nights.
2. I also plan to carry RV Anti freeze with me.
3. I like the idea of a little fan to move warm air under the shower floor.
4. The underside of the camper is pretty much covered - does that help hold a little warmth from the cabin, helping the fresh water and holding tanks to not freeze?
5. One past entry said something about not getting too concerned until night time temps dropped below 30 degrees for 8 hours.  Based on experience, does that mean if lows "dip" below freezing for a couple hours at night the drains and dump lines survive OK?
6. I also think I read something about spraying the drains and holding tank cap and valve with RV Antifreeze?  Can someone say more about that?  Would that help if there is water in those tanks? 
7. There were detailed discussions about wrapping pipes and elbows with heat coils but as a retired nurse I don't think that is in my skill set and may not be necessary for my route.  
8. I also saw some discussion of skirting the camper and using some sort of heat pad?  Can someone say more about that as well?  I'm having trouble picturing how to skirt the camper short of wrapping it up in a sheet a canvas and the only heat pad I can picture is one for a sore back! I don't plan to stay in any one place for more than a couple nights and would like to keep setting up and striking camp as simple as possible.

I am so excited to start my first big adventure with JJ (Joanne's Joyride) but will feel much better once I am comfortable with a frozen pipe prevention strategy.

DougH

@jtalarek ; Everyone here can empathize with you. Whether winter campers, or just hoping for an early spring or late fall trip in our teardrops, all of us wonder if there's anything we can do besides just going winterized (tent camping, but on wheels and with a great heater) .

I've been able to camp a couple seasons winterized, carrying my own water containers, and pouring plenty of RV antifreeze into the black and gray tanks whenever I use any water.  That really does work pretty well (so far), but it means no real showers and doing dishes with tiny amounts of water.

But the experimenters here want to use less PG antifreeze or want access to more water without diluting every ounce of water with an ounce or two of the pink stuff.  That capability really requires a good deal of effort in the T@B basement area. 

4.  No.  There's big gaps leading to the "basement" near the wheels, and if there's any wind at all hardly any heat from the cabin gets to the gray and fresh tanks or the tubing from the fresh tank. The black tank will stay thawed since it's above the floor. 

5.  So far that's been everyone's experience. I don't remember seeing anyone with a broken fresh water intake tube from an occasional dip down to 30,  Possibly leaving the sink dripping overnight might help in that kind of situation. More common (correct me if I'm wrong please) are cracked toilet valves when putting the trailer in storage over the winter without thoroughly draining that tubing.  Same with the black and gray tank drain valves.

6.  No, that wouldn't help with pure water in the black or gray tank drain areas if you have the camper in 20F conditions.  The whole drain and valves would freeze and possibly crack.  Not the end of the world since those parts are replaceable and not hideously expensive.  But still. 

8.  I grew up skirting my parents trailer.  It takes a good deal of time and would be a hassle if you are moving every couple days.  Folks use foam sheets duct taped together, canvas or even plastic tarps to keep all the wind from below the camper, run heat tape on the water intakes and water drains to the campground connections, add a couple infrared lights or other heat source underneath, then pile snow around the skirt for extra insulation. Common technique for people staying somewhere a fairly long time.

In another year or so plenty of forum members will have documented methods for building a real basement, using heat sources, or a combination of the two.  At that point I would hope that Nucamp or generic RV repair shops might take on using those documents to turn a T@B into a four season camper for some reasonable price.  The place I store our teardrop is frequently visited by small 1-5 person mobile RV repair firms who top off propane, recaulk roofs, and do minor repairs.  It might not be that hard to find a shop that will do everything needed for $2-3k parts and labor.

Looking forward to seeing pics of JJ on the road! 

[Deleted User]

I've been asking NuCamp and Little Guy before that to please offer a heated underbelly on the T@Bs.  I almost bought a Airstream this past Spring just because it is a four season camper, but I greatly prefer the T@Bs so I bought a second one in April 2019 and I find myself again spending countless hours trying to research how to modify the bottom to be heated!  The first year NuCamp puts out a heated underbelly, I'm buying a new one!  (unless I can figure out how to get things set up on my 2019 model)

jtalarek

Thank you so much, Doug, for your comments.  I will take the simple precautions, watch the weather, and leave the rest to the camping gods.  Will let you all know how it goes and will watch for basement plans in the future.

DougH

See you out there...

Letsgo

How long will the propane last if running fridge and Alde in tab 320?

ChanW

@Letsgo, the fridge doesn't use much. The Alde uses a little when it's warm out and a lot when it's cold. So the propane will last anywhere from a couple days to a couple of weeks or a month!

Letsgo

Thanks for the reply! 

ChanW

Letsgo said:

Thanks for the reply! 

It really depends on too many variables to give an answer to your question.

• Where you're going to be camped out and expected temps
  
• How much of your day you expect to be in the Tab
• If you have a side tent you'll be heating too
• If you sleep with the heat on or off (my DW and I love sleeping in the cold, with a pile of blankets and a down comforter)
  
• etc etc

So, when we camped in Ontario one winter in January, the outdoor temps got down to -5°F at night, we camped for three nights I think, during the days outdoors a lot, xc-skiing and skating, cooking breakfast & dinner outside, etc.

We did leave the heat on low in the Tab while we were out during the day.

I think we maybe went through around a quarter to a half tank of propane.

(We didn't really use or need the fridge.)

DougH

Solar Powered Basement Heating

Sorry... long post.

Weird. This thing may actually work. This isn't a HOWTO, but just one way that maybe gets the job done using electrical heating to allow winter camping with a bit more freedom of water use.  Numbered list below goes with the pictures.

1. Put the T@B up on ramp blocks to give yourself more room to work underneath.
2. Here's the hardest part.  Taking things apart.  Once you've finally gotten around to starting something, everything else is easy.  Or am I the only one who puts too many things off to another day? There's six hex bolts loosely holding the center of the coroplast liner under the camper to some aluminum corner brackets.  And there's a dozen or two square tip driver screws going through some termination strips, the coroplast, and into the frame around the edges of the camper.  Remove everything.  Watch out for falling leaves or rodents.
   
3. Some of the termination strips look similar so I labeled everything.
4. Save off the screws somewhere safe.  I thought I lost two of them and had to improvise with some hex nut machine screws and an air wrench when putting everything back together.  Once I was all done, naturally I found the missing ones.
5. At forum members' suggestions, I'm using PWM controllers to vary how much current goes into the tank heating pads and heat trace cable segments.  Thanks again.  So I bought eight thermocouples and a couple display units to Velcro near the bathroom entrance.  Cheap, but accurate to about one degree Fahrenheit.
6. Drill a hole under the TV in the floor to run all the thermocouple leads through.  Ignore the one labeled "fridge"... that became the black tank sensor.  Drill another hole in the back storage cabinet to run all the wiring up to the PWM controllers (if that's where you want to have the control knobs).
   
7. The black tank is above the floor and doesn't need heating (we think).  But the gray tank, fresh tank, the blue pex lines and drain for the fresh tank, and the white fill tube for the fresh tank all need protection.
8. Start by putting several layers of thick aluminum foil on the drains and the fresh tank tubing.  Just to spread the heat more evenly.
   
9. Install the tank pads and cover with Reflectix.  Not sure how conductive the coroplast liner is, so I didn't want the heating panel resting right against the bottom plastic cover.
10. Wrap the drains and piping with segments of heat trace cable.  I used 15W per meter self regulating cable.  It's a pain to whittle away the leads, then seal the other end. Very time consuming, and longest part of the job.
    
11. While the black tank is above the floor, several of us weren't sure if it would stay thawed at 0F, so add a computer fan and switch in the cabinet under the sink to blow air from the heated cabin into the area around the black tank.
12. I mounted four controllers and their control knobs to a piece of Baltic Birch.  One for the black drain and gray drain.  Another for the fresh tank tubing and drain.  Third for the gray tank heating pad.  And the fourth for the fresh tank heating pad.  Before putting any insulation on, I tested each segment as it was installed to make sure it was heating up properly.
13. Remove a window of aluminum foil from each component as far away as feasible from any heating pad or heat trace cable, and attach a thermocouple end against the PVC or pex material to pick up the actual temperature of the component, instead of the warmer thermally conducting aluminum foil.  Then add plenty of layers of foam and foil insulation material.  I didn't want to use fiberglass since you have to wear gloves, and I've heard it doesn't behave well when it gets wet.  I've been testing the completed system, but need to use a laser thermometer to see how well all the insulation is working by measuring the underside of the camper, then something like the black drain pipe cover below freezing while the heat circuits are on.  Fingers crossed if it's 20F outside, and the drain and contents are 35F, the outside of the drain is only a few degrees above 20F, so I'm not wasting too much energy heating the whole world.
14. Run the sealed heat trace cable right up to the edge of the fresh tank drain, and wrap the end of each drain trace cable around the front of the black and gray tank drain valves to help protect them too.
15. Sorry about the mess.  That's two of the batteries, the inverter, solar controller, switches for a vent fan (inverters can get hot in the summer) and all the heating elements (switches facing into the camper).  And a basket of pots and pans.  I created a 4-way pigtail from a fused DC hot lead, and another pigtail for the negative side, and then four pairs of wires from the heating elements up through a wiring shroud into a shelf in the back corner near the speaker that I'd added earlier (a place to put phones when sleeping).
    
16. The control module is just vertically mounted in front of the battery monitor and inverter switch with the top open to the air (but not visible unless you put your head close to the panel).  Knobs near the bottom for adjusting easier if lying down.  There's around 0.25A generated all the time just from the PWM controllers when the main switch is turned , and probably more once they're running higher currents, so I need the heat to be able to escape.  On the bright side, it helps heat up the camper.  Once everything seems to work, button everything back up and put the liner back on the bottom of the camper.  There's several huge openings to the basement.  Cover them all with something, and seal up all the gaps around the corners and drains to make it relatively air tight.  Or at least a LOT more air tight than the stock configuration.
    

Results:

Turns out the computer fan for the black tank works wonders.  I put a thermocouple 8 inches back from where the fan was, and the area jumps ten degrees over a half hour once the fan is on.  And the fan only pulls 0.2A.

Haven't been out in the teens or colder yet.  Only testing in the 20s, 30s, and 40s.  I've got 300W of panels on the roof with 300Ah of battery and the particular panels I use generate two thirds that amount even when the sun is 70 degrees off axis, so in the mountains at elevation, and facing the South, I expect to get somewhere between 200-300W as long as it's clear for maybe 4-6 hours a day.  So I was hoping to use only 50-100W/hour to leave the heating on all the time, to leave me enough juice for morning coffee, lights, etc. without having to plug in extra portable solar panels.

So far, when it's right at freezing, the thermocouples all read that value except the one for the inside.  With the sun out and blinds open, it's always 5-10F warmer inside from solar heating.  I've done several test sequences, each over an hour's time period.  Warming the camper to 60F for a half hour first.  By the way, the Alde temperature gauge is very accurate.  Or at least matches a thermocouple placed next to it for measuring the real inside temperature.  Then measuring every fifteen minutes after dusk, the outside temperature thermocouple typically shows a drop of several degrees over that hour.  But applying only 2A total to the black and gray drains, and 1.5A on the gray tank (both a quarter full), during that hour the black tank drain rises over 3 degrees, the gray tank drain rises 9 degrees, and the gray tank rises 2.5 degrees.  Not bad for only 45W of juice, and that was in just one hour.  I fully expected it would just hold the existing temperatures as it got colder outside at less than 50W.  Happy.

I haven't done any fresh tank testing yet.  I want to wait until I get up at elevation and see how much power I get in December and January over a typical clear day.  Draining the fresh tank and blowing out the lines will be my first countermeasure if I get cloudy skies and can't heat all tanks and plumbing.  That or checking into an RV campground with electric.  But in Colorado in the winter, there's only a handful of those open all year that are in the mountains.

I'll update with more details in another month or two once I've found how few watts it takes to keep the drains and gray tank hovering around 35F when it's 25, 20, or 15F outside. Thanks again for the suggestions on this thread.

ChanW

Very interesting @DougH ... Especially that you get such relatively high power output at this time of year. I don't remember if you mentioned, are your panels angle-adjustable?

DougH

@ChanW : No, aside from being on a curved surface up top.  The latest generation BougeRV flex panels are supposed to be more resistant to weather damage, and are very sensitive and efficient (exactly pointed direct sun not needed), but the previous generation seemed to be even more so.  They used to be coated in what looked like little 1mm hemispheric lenses. Even before the sun cleared the horizon in the morning I'd be getting 30-40W.  The newer ones (hail storm) are a flat surface.  Still multilayer ETFE construction, but I don't get ridiculous readings like positive wattage off the full moon at night anymore.  I know some folks only get half the spec'ed power from their panels, but some reviewers on this brand have measured full 100W on their 100W panel.  If any Amazon review can be believed.  I've not seen 300W yet.

I should mention when I said the Alde temperature was accurate...  that was at steady state.  It was in the 20s again this morning, so I did a 35W test from a stone cold camper.  The camper got to 60F in 40 minutes, but the Alde thermometer was still reading in the 40s.

ChanW

Huh! That's very interesting!

I don't see why you would call moonlight solar energy ridiculous. Some of us are counting on it! (With enough panels, you could even run your AC at night.... kidding!)

DougH

Funny, but I am tempted to get a couple more and just mount them in a frame as a portable way to get to net 300-500W in the noonday sun.  But that'll have to wait for when this battery bank dies... since I'd want to bump up the bank to 500Ah, and would also need a bigger Victron controller.  Sad part of being retired is the budget only allows RV toys every few months, and only if nothing else needs maintenance.  That said, this project was very cheap to do, aside from the week and a half of labor.

Tabaz

DougH - where did you pull the 12V power from for the Noctura fan in picture 11?

DougH

From the 12V line for the fridge.

Tabaz

What route did you use to the new fan?