CL Fresh Water Anti Freezeup System

[charliem]

[font size="3"]Hey all you techies (My technical staff),

I'm floating this idea for your evaluation and comments. I have an idea to greatly reduce the potential of fresh water system freezing on CLs. My proposal is specifically tailored to the 21RBS, but might be adapted to other CLs. Design points are:

[/font][ol type="decimal"][li][font size="3"]Intended for short overnight drops into 20s or high teens. Not an annual winterization.[/font][/li][li][font size="3"]Intended for occupied trailer use where interior temperature is above freezing.[/font][/li][li][font size="3"]May be used while towing if outside temperature is below freezing.[/font][/li][li][font size="3"]Uses propane to supply heat energy; electric only to control and circulate.[/font][/li][li][font size="3"]Uses existing pump to circulate water in a closed loop. No water is wasted while dry camping.[/font][/li][li][font size="3"]The pump runs in only short spurts.[/font][/li][li][font size="3"]Will safeguard unattended trailer as long as 12V and propane are available. Great for extended beer runs.
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As previously reported the 21RBS water system contains uninsulated exterior piping which will freeze during cold nights. A mapping of the fresh water system reveals that drawing hot water from the kitchen faucet draws cold water from the FW tank and pulls it through all cold and hot water pipes inside and under the trailer except a few very short segments close to the inside of the trailer. On the two long runs that cross from side to side under the trailer the hot and cold pipes run next to each other and in contact with each other.

[attachment id="910" thumbnail="1"]

The first step is to insulate the pipe runs under the trailer. This can be done with pool noodles or pipe insulation. The hot and cold pipes should be held in contact with each other to maximize heat transfer from the hot to the cold pipes.  On my trailer I will have to free the pipes from under the waste tank brackets and re-secure them with zip ties.

The next step is to add a valve and check valve as shown in the diagram. The valve is solenoid operated from a manual switch, a timer, or a temperature sensing thermostat. More on this later.
When the valve is open the hot water from near the kitchen sink is allowed to flow back into the unpressurized filler port of the FW tank. The red and blue arrows on the diagram show water flow when the valve is open. No additional circulating pump is required. The onboard water pump provides the pressure for the gravity feed. Heated water is returned to the FW tank and heats the tank a little or a lot depending on how much water is allowed to flow.

Control of the electric valve can be by one of several means. I'm considering using a 12V programmable timer to operate a minute or two every few hours or a programmable thermostatic controller sensing the pipe temperature somewhere in the piping system. A short periodic run will heat the pipes and a longer run could actually reheat the FW tank if desired. For short overnight freezes with thaws the following day, and a relatively full FW tank, I don't think long runs will be necessary. This is still up in the air and I'm looking for suggestions. All the valve and control hardware is available from amazon or hardware stores and there is plenty of room for installation. Your thoughts please.[/font]

[pjcd]

Funny,,,,I was working on the same set up!   8^)

[joanne]

Picking up on your earlier thread:

http://livinlite.proboards.com/thread/674/21rbs-fresh-water-schematic

As indicated in that thread, my first step was to move all of the plumbing into the heated envelope of the trailer, leaving only the fresh water tank exposed. I'm also going to install shut-offs on the wet batch supply so that I can run the bath dry while leaving the rest of the trailer wet. I may also install shutoffs on the outside shower so that can stay dry and be allowed to freeze.

I don't see why that will not work, and am planning to do something similar. My current thought is to use a manual 3-way valve spliced into the fresh water tanks vent hose and supply HW via vent. I'm doing that only because it's easier to find a valve-fitting for the vent hose than for the fill hose.

--Mike



 

[charliem]

[font size="3"]Mike,

Thanks for the reply and I did study you're earlier post. There are some external pipe runs I could bring inside and I considered installing valves to shut off the shower, but it seemed more work than my present solution and less functional. You're 16 lends itself to a different solution, but that's what it's all about.

Your point on using the vent vs filler port is excellent. I was wondering how many series adapters it was going to take to hook to the supply hose. Also, I was concerned with the filler hose's ability to withstand hot water. All solved, I'll go with your suggestion. I checked and there's room. Thank you.

One thing I will add is an adjustable shutoff in the line to the vent to allow controlling the flow rate. This would slow the flow to extract most of the usable heat before dumping into the FW tank. It also allows for the time constant of the hot pipe to cold pipe transfer under the trailer, but enough engineer speak!
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[charliem]

[quote timestamp="1441513920" author="@pjcd" source="/post/14890/thread"]Funny,,,,I was working on the same set up!   8^)[/quote][font size="3"]OK, so jump in here. You know the rules. If you take an idea , you leave and idea    Camp on. [/font]

[joanne]

My thinking on the wet bath shutoffs is primarily to protect the toilet valve from accidental freezing in the case that something goes wrong. I figure the the toilet will be the most expensive and most likely thing to break if I don't keep it warm enough, so filling it with pink and leaving the pink untouched it my safest strategy.

I didn't think of bundling the hot and cold in the same insulator, but because my plumbing is all inside, I don't think I have to. If anything, I'll remove the insulation so the plumbing is more exposed to the inside camper temperature, rather than as is now with insulated plumbing in the interior of the camper. Or perhaps because most of the plumbing is against the outside walls, only insulate the wall side of the plumbing.

What's your thoughts on insulated vs non-insulated interior runs?

[charliem]

[font size="3"]Mike,

Not sure what model toilet is in your 16, but the FW supply valve is vulnerable if water is left in it. I discovered that early on. Not hard to replace and not terribly expensive. Just inconvenient. I carry a spare now. 

The parallel hot/cold pipe runs under the trailer were a [/font][font size="3"]pleasant surprise[/font][font size="3"]. When I saw that the brain light came on. Inside your trailer I think the insulated piping is mox nix. If your interior heat fails it might postpone the inevitable a short time. I'll leave all my interior piping uninsulated, but I do leave the cabinet doors ajar to encourage air circulation.
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[charliem]

[font size="3"]Update: The check valve is unnecessary, going into the unpressurized tank. A holdover from prior thinking.
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[tinkeringtechie]

I like where you're going with this. How about a few loops of tubing inside the trailer on a diverter valve that can be turned on in "comfort" mode and then you'll have radiant floors?

What are you going to do about the low point drains? Those are kinda dead ends.

[charliem]

[font size="3"]The radiant floor heater will have to wait for the NextGen implementation, after I'm through helping LL layout the 28RBS      The low point drains are a consideration, but I'm hoping that insulating them will allow allow enough conduction from the pipes above to keep them warm. I may also shorten the upstream sections a bit. I've always thought they were a bit long. I'm leaning toward a timer driven solenoid valve. Amazon has a 12V timer ($13) that provides 17 events per day of one minute minimum. I think 17 or less one minute runs, with flow adjusted by the inline manual shutoff valve, will work. Stay tuned and keep thinking.
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[charliem]

[font face="arial" size="3"]The HW circulator is installed in the 21RBS and seems to be working in the driveway.  Time and miles will tell.
The circulator is designed to combat overnight subfreezing temperatures with the warm up the next day, but will also function while being towed which allows towing in freezing temps. Although primarily designed for subfreezing operation with city water disconnected the pushbutton provides manual operation in cases where fresh water supply and/or gray water storage are limited. The pushbutton minimizes wasted water while waiting for HW at the sink or shower. It takes 15-20 seconds for the HW to completely circulate throughout the 21RBS.

[attachment id="1056" thumbnail="1"]  [attachment id="1057" thumbnail="1"]  [attachment id="1058" thumbnail="1"]    [attachment id="1061" thumbnail="1"]  [attachment id="1060" thumbnail="1"]

The timer is programmed to open the valve for 1 minute every 45 minutes over a 12 hour overnight period. SW1 powers the timer and indicator light. The switch handle and LED give an easy visual indication of ready and is easier than pushing the timer Auto/On/Off  button and reading the tiny display. The current time is maintained 3 years between recharges and if not used in 3 years it probably wasn't needed anyway. R1 limits the LED current. I used a 10K resistor and an UltraBright LED that illuminates quite well at 1mA.  

The ball valve limits flow to prevent backflow out of the vent hose. Hint: Add a section of clear vinyl to adjust without running outside. Be sure to elevate the vent hose to maintain slope and drainage.

Insulating the below trailer piping is the first step:
[a href="http://livinlite-owners.com/thread/1681/insulating-water-pipes-on-21rbs?page=1&scrollTo=16950"]http://livinlite-owners.com/thread/1681/insulating-water-pipes-on-21rbs?page=1&scrollTo=16950[/a]

Here are some parts I used:
[a href="http://www.amazon.com/12v-Normally-Closed-Brass-Solenoid/dp/B005EP0WAO/ref=sr_1_3?ie=UTF8&qid=1451588576&sr=8-3&keywords=duda+diesel+solenoid"]http://www.amazon.com/12v-Normally-Closed-Brass-Solenoid/dp/B005EP0WAO/ref=sr_1_3?ie=UTF8&qid=1451588576&sr=8-3&keywords=duda+diesel+solenoid[/a]

[a href="http://www.amazon.com/Neewer%C2%AE-Digital-Power-Programmable-Switch/dp/B00AJGX0JS/ref=cm_cd_ql_qh_dp_i"]http://www.amazon.com/Neewer%C2%AE-Digital-Power-Programmable-Switch/dp/B00AJGX0JS/ref=cm_cd_ql_qh_dp_i[/a]

[a href="http://www.amazon.com/dp/B00835OJBA/ref=biss_dp_t_asn"]http://www.amazon.com/dp/B00835OJBA/ref=biss_dp_t_asn[/a]

[a href="http://www.amazon.com/Anderson-Metals-Brass-Fitting-Degree/dp/B006PKLD4Q/ref=pd_sim_328_3?ie=UTF8&dpID=41gJSk9HCBL&dpSrc=sims&preST=_AC_UL160_SR119%2C160_&refRID=02XWRC9SAHN7EDTXRR6D"]http://www.amazon.com/Anderson-Metals-Brass-Fitting-Degree/dp/B006PKLD4Q/ref=pd_sim_328_3?ie=UTF8&dpID=41gJSk9HCBL&dpSrc=sims&preST=_AC_UL160_SR119%2C160_&refRID=02XWRC9SAHN7EDTXRR6D[/a]

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[joanne]

Really slick. I'll reference this when I finally decide to do something similar.

[jerrybeaird]

Charlie.....

This is GOOD stuff!!!  A setup like this is VERY useful when there is an unexpected overnight freeze.  We do have them down in Houston once in a while and with this setup you don't need to use the antifreeze setup and can continue to camp on.

Thanks!

[charliem]

[quote timestamp="1451619182" author="@nd1979" source="/post/17396/thread"]Charlie.....

This is GOOD stuff!!!  A setup like this is VERY useful when there is an unexpected overnight freeze.  We do have them down in Houston once in a while and with this setup you don't need to use the antifreeze setup and can continue to camp on.

Thanks![/quote][font size="3" face="arial"]Exactly! We even get them in NW Florida. With the circulator, a small ceramic heater and open cabinet doors you should be good overnight. Camp on. [/font]

[daplumbr]

Valuable for the fresh water and grey tank space savings alone; not wasting water waiting for hot at a tap. Besides, this looks like fun. My camper is getting snowed on today, so I won't get to this real soon.