[font size="3"]Attached is a physical schematic of the 21RBS fresh water system. Although a schematic, the drawing attempts to present the physical location of components and physical routing of water lines. Although unverified I expect it is close for 21BHS and 28BHS models with the exception of the bathroom sink placements.
[attachment id="937" thumbnail="1"]
[/font][font size="3"]My main purpose in constructing the diagram was to understand the water flow inside and below the heated area. I am looking at ways to freeze-proof the exposed piping during brief overnight inhabited stays in cold weather. Stay tuned.
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Charlie:
Let me give you some thoughts on this subject:
Years ago in a non LL camper we were camped at Lake Tahoe when the temps got down to about 24 deg F overnight. The camper was built similar to LL's. No freezing, but I did flush the toilet a few times at night to move some water through the system. I was careful not to pull out the next morning until the air temp warmed up to 32+ as moving along at 60 mph will quickly freeze up the water system.
For tougher conditions than this there are two escalating options. You can insulate the exposed tubing with foam insulation, which will probably cover you to 20 deg overnight temps. But this depends on it heating up the next day. Extended low temps at night and below freezing during the day calls for a different solution.
This company makes 12V heating cable: http://www.oemheaters.com/c-983-freezstop-12v-heat-cable.aspx. If you were to run their 3.5 watt per foot cable under foam insulation you probably would be good to near zero deg F overnight and daytime temps below freezing.
Let's assume that you have to run 20' of heat cable. That will be 70 watts or about 6 amps. That will run down your batteries pretty fast, but with their temperature controlled switch you might only need 4 hours every 24 so 24 amp hours per day. That should work ok for a few days without recharging.
I know that high end 4 season campers seal the bottom and blow furnace air over the three water tanks. But unless you are going to use the camper for weeks in sub zero temps, I wouldn't worry about it. Even if the fresh water tank freezes an inch of ice on top, it isn't going to hurt anything or limit its use if the tubing is insulated. Same with the grey and black water tanks.
All of the foregoing assumes no AC power connection. If you do have power then there are easier ways, such as putting a temporary skirt around the trailer and putting a small space heater underneath. Or install the heat cable discussed above and don't worry about battery draw.
Good luck on your project. What temp parameters are you working towards as well as number of days without moving? With AC power or without. Any recharging capabilities if without?
David
[quote source="/post/5252/thread" timestamp="1416669401" author="@david"]Charlie:
Let me give you some thoughts on this subject:
Years ago in a non LL camper we were camped at Lake Tahoe when the temps got down to about 24 deg F overnight. The camper was built similar to LL's. No freezing, but I did flush the toilet a few times at night to move some water through the system. I was careful not to pull out the next morning until the air temp warmed up to 32+ as moving along at 60 mph will quickly freeze up the water system.
For tougher conditions than this there are two escalating options. You can insulate the exposed tubing with foam insulation, which will probably cover you to 20 deg overnight temps. But this depends on it heating up the next day. Extended low temps at night and below freezing during the day calls for a different solution.
This company makes 12V heating cable: http://www.oemheaters.com/c-983-freezstop-12v-heat-cable.aspx. If you were to run their 3.5 watt per foot cable under foam insulation you probably would be good to near zero deg F overnight and daytime temps below freezing.
Let's assume that you have to run 20' of heat cable. That will be 70 watts or about 6 amps. That will run down your batteries pretty fast, but with their temperature controlled switch you might only need 4 hours every 24 so 24 amp hours per day. That should work ok for a few days without recharging.
I know that high end 4 season campers seal the bottom and blow furnace air over the three water tanks. But unless you are going to use the camper for weeks in sub zero temps, I wouldn't worry about it. Even if the fresh water tank freezes an inch of ice on top, it isn't going to hurt anything or limit its use if the tubing is insulated. Same with the grey and black water tanks.
All of the foregoing assumes no AC power connection. If you do have power then there are easier ways, such as putting a temporary skirt around the trailer and putting a small space heater underneath. Or install the heat cable discussed above and don't worry about battery draw.
Good luck on your project. What temp parameters are you working towards as well as number of days without moving? With AC power or without. Any recharging capabilities if without?
David[/quote]
[font size="3"]David,
Once again an excellent and well thought out response. Thank you.
I have looked at most of your suggestions. I wanted to understand why LL crossed the underside twice. I think is was for their manufacturing convenience, but it may also aid low point drainage. I thought about closing the gap between kitchen and bath, but decided to leave it as is. The OEM routing has one big, and maybe unintended, advantage: drawing hot water from the kitchen sink using the pump exercises all hot and cold exposed piping except a small section at the low point drains. This suggests simply running a quart of hot water down the drain from the kitchen a few times a night.
I looked at insulation, but LL's routing near the waste tanks and within the tank mounting brackets makes it difficult. Same for heat tape, but the thermal putty from your referenced link may make it possible. I measured about 18 feet required. I looked at 12V and 120+inverter+controller solutions, but I'm gravitating toward a circulating HW approach. Using propane for the heat and electricity only for control seems a better solution.
Looking at the diagram you see that connecting the hot and cold water feeds under the kitchen sink with a small 12V circulating pump would excercise all exposed pipes. The pump could be controlled by a small timer. Seven day 12V timers with short run times are available and cheap. However, now I'm considering just dumping HW from the kitchen feed directly back into the FW tank. This can be accomplished with a timer controlled solenoid valve under the kitchen sink connected to the FW overflow hose which is also accessible in the pump cabinet. The advantages are minimal electrical demand, no additional pump, a very controllable process, and some heat added to the FW tank.
I'm only trying to accommodate nights when we're staying in the camper and outside temps drop to the mid or low 20s for a few hours followed by a daytime warmup. As you point out the FW tank has enough thermal mass and the waste tanks can be dealt with using antifreeze if necessary.
For now I'll try the " run HW in kitchen now and then" approach until I think the thing through. Your thoughts?
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Charlie:
If all you need is protection from low to mid 20s temps overnight with temps warming to well above freezing during the day, then I would try your trick of running a quart or so of hot water down the drain once or twice at night and maybe insulating the dead leg if you can get to it. Heck I get up more than that overnight, so no sweat!
David
[font size="3"]Yes, David, I agree. I also get up a few times a night. My only other thought was the circulating system would work automatically if, for some reason, I had left the camper unoccupied for a time. Maybe spent a night in a nearby town. Probably won't happen so probably no issue.
If by "dead leg" you mean at the low point drains, yes I can get to and insulate them. Camp On!
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David, your response reaffirmed my thoughts on camping through an occasional cold night or two. Thx
[quote source="/post/5252/thread" timestamp="1416669401" author="@david"][/quote]"I was careful not to pull out the next morning until the air temp warmed up to 32+ as moving along at 60 mph will quickly freeze up the water system."
David, I'm not sure why this would occur. Wouldn't 34 degrees blowing at 60mph still be 34 to the pipes and liquids?
Dave:
Yes, of course. Once you hit 32+ it doesn't matter how fast you go and how low the so called wind chill is. But at anything below 32 driving at 60 mph increases the heat transfer to the exposed pipes dramatically and can quickly freeze them.
David
[font size="3"]And when sitting still there is some ground heat trapped under the camper which is "gone with the wind" :P. OK, I'll expect 20 lashes for that! :)
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[quote source="/post/6290/thread" timestamp="1422626399" author="@david"]Dave:
Yes, of course. Once you hit 32+ it doesn't matter how fast you go and how low the so called wind chill is. But at anything below 32 driving at 60 mph increases the heat transfer to the exposed pipes dramatically and can quickly freeze them.
David[/quote]We need to devise a system where hot gas from the tow vehicle exhaust is routed into a manifold that distributes the heat below the camper. That way when you get to your destination your trailer is preheated. It may also be filled with poisonous gasses and smell like car exhaust, but I'm sure we can figure that out too...
[quote source="/post/6303/thread" timestamp="1422638521" author="@tinkeringtechie"][quote source="/post/6290/thread" timestamp="1422626399" author="@david"]Dave:
Yes, of course. Once you hit 32+ it doesn't matter how fast you go and how low the so called wind chill is. But at anything below 32 driving at 60 mph increases the heat transfer to the exposed pipes dramatically and can quickly freeze them.
David[/quote]We need to devise a system where hot gas from the tow vehicle exhaust is routed into a manifold that distributes the heat below the camper. That way when you get to your destination your trailer is preheated. It may also be filled with poisonous gasses and smell like car exhaust, but I'm sure we can figure that out too...[/quote]On the road heater, think beer wort chiller in reverse. You only need to put one more hole (well, maybe 2) in the camper big enough for a 4 inch pipe. Run the 4 inch pipe through the camper and out again. Slip a 2 in pipe inside the 4 inch, fill the gap between the 2 with heat conducting liquid and seal. Hook your exhaust up to the 2 inch pipe and voila instant radiant heater!
[quote source="/post/6303/thread" timestamp="1422638521" author="@tinkeringtechie"]We need to devise a system where hot gas from the tow vehicle exhaust is routed into a manifold that distributes the heat below the camper. That way when you get to your destination your trailer is preheated. It may also be filled with poisonous gasses and smell like car exhaust, but I'm sure we can figure that out too...[/quote][font size="3"]Techie, have you been sniffing something again??? :-/ :-/
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[quote source="/post/6305/thread" timestamp="1422650181" author="@charliem"][quote timestamp="1422638521" source="/post/6303/thread" author="@tinkeringtechie"]We need to devise a system where hot gas from the tow vehicle exhaust is routed into a manifold that distributes the heat below the camper. That way when you get to your destination your trailer is preheated. It may also be filled with poisonous gasses and smell like car exhaust, but I'm sure we can figure that out too...[/quote][font size="3"]Techie, have you been sniffing something again??? :-/ :-/
[/font][/quote]Baby poo and mac'n cheese (not at the same time obviously) :)
[quote timestamp="1416666250" source="/post/5251/thread" author="@charliem"][font size="3"]Attached is a physical schematic of the 21RBS fresh water system. Although a schematic, the drawing attempts to present the physical location of components and physical routing of water lines. Although unverified I expect it is close for 21BHS and 28BHS models with the exception of the bathroom sink placements.
[/font][font size="3"][/font]
[font size="3"]My main purpose in constructing the diagram was to understand the water flow inside and below the heated area. I am looking at ways to freeze-proof the exposed piping during brief overnight inhabited stays in cold weather. Stay tuned.
[/font][/quote]On my 16BHB, most of the plumbing was under the trailer. With no slide in my camper, was pretty simple to re-route both hot and cold to stay inside the heated area:
[img style="max-width:100%;" style="" src="http://i57.tinypic.com/2hoe16f.jpg"]
P = pump, W = Water heater.
The gap between the galley and dinette is filled with built-in shelve that i fabricated out of aluminum, and the gap by the wet bath is only a few inches, so the plumbing is well hidden.
I'm also thinking of either adding a 12v tank heater to the fresh tank or adding a valve that would allow me to pump hot water into the fresh tank through the filler.
The thought is that I'll be able to winterization somewhat.
But in cold weather last weekend, the space under the wet bath was cold enough to freeze when the outside was 18f and the inside was 55f, so I'll have to figure out how to keep that space and the space under the bunk warmer.
--Mike
[font size="3"]Mike,
Looks like a great start on the problem. I read your earlier post as I started looking at the 21RBS, but it wasn't as simple as yours. It's hard to tell from the LL pictures where your fresh water filler is, but if it's on the right near the galley you're home free. Just add a valve to take pressurized hot water under the sink and dump it into the unpressurized FW filler hose. A small 12V valve and cheap 12V timer could automate the process. From your diagram it would exercise the entire water system and be a lot easier on the battery than a 12V tank heater if you're off grid. It may also solve your bath/bed problem, but if not, adding some passive vents may be sufficient. If not the addition of one or two 12V computer fans should do it.
Keep us informed.
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You guys are hard core. :-)
[quote timestamp="1422711051" source="/post/6321/thread" author="@charliem"][font size="3"]Mike,
Looks like a great start on the problem. I read your earlier post as I started looking at the 21RBS, but it wasn't as simple as yours. It's hard to tell from the LL pictures where your fresh water filler is, but if it's on the right near the galley you're home free. Just add a valve to take pressurized hot water under the sink and dump it into the unpressurized FW filler hose. A small 12V valve and cheap 12V timer could automate the process. From your diagram it would exercise the entire water system and be a lot easier on the battery than a 12V tank heater if you're off grid. It may also solve your bath/bed problem, but if not, adding some passive vents may be sufficient. If not the addition of one or two 12V computer fans should do it.
Keep us informed.
[/font][/quote]The 16bhb is probably the simplest & easiest arrangement of any. The power center, outside shower, fresh water fill and pump are all under the rear bunk on street side, the that bunk is hinged for easy access, and there is lots of space to work on things.
So there already is hot water a foot away from the fresh water fill. :)
[font size="3"]Mike,
The only reservation I have is whether the large plastic fill hose can withstand the 140F hot water. Can't find any info on the material. Any clue?
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[quote source="/post/6343/thread" timestamp="1422744523" author="@charliem"][font size="3"]Mike,
The only reservation I have is whether the large plastic fill hose can withstand the 140F hot water. Can't find any info on the material. Any clue?
[/font][/quote]It's labeled:
[span] [/span]FLEXAUST PVC 1-1/4" IAPMO-TM
Perhaps this?
[span] [/span] [a href="http://www.flexaust.com/product/potable-water-hose/"]http://www.flexaust.com/product/potable-water-hose/[/a]
I'd need to find some kind of tee fitting to get from 1/2" to 1-1/4"
Quote from: @michael" source="/post/6347/thread" timestamp="1422755354Quote from: @charliem" source="/post/6343/thread" timestamp="1422744523[font size="3"]Mike,
The only reservation I have is whether the large plastic fill hose can withstand the 140F hot water. Can't find any info on the material. Any clue?
[/font]
It's labeled:
[span] [/span]FLEXAUST PVC 1-1/4" IAPMO-TM
Perhaps this?
[span] [/span] [a href="http://www.flexaust.com/product/potable-water-hose/"]http://www.flexaust.com/product/potable-water-hose/[/a]
I'd need to find some kind of tee fitting to get from 1/2" to 1-1/4"
[font size="3"]I'll look when I get home. I didn't see any marking but it's tight where mine is. If you're right and it is PVC then no problem. Thanks
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