I have always loved Reflex insulation, it is R-4 with only about 3/8" thickness, and is not going to support mold, and will be able to tape it closed to prevent air movement to and from the space.
I bought a 75' roll that is 4' wide, and made a window shade for each of my windows, and the front windshield in my motorhome, mostly for blackout when camping in a city, but also to insulate things too. I store it under my rear bed when not in use. You can buy it at Lowes or Home Depot.
I think someone mentioned putting a gallon of non-toxic antifreeze into the holding tank, and leaving the grey water to drain onto the ground in the hunting camp, it is OK in the woods, but not PC in a parking lot with 20 other RV's at the dog show. A 1/2 gallon of pink non-toxic antifreeze should be fine in each tank, it will prevent them from turning to ice and damaging anything.
For the fresh water tank, some cheap wine is what my buddy did while at the 1980 winter Olympics in upstate New York, I think it got down to about -5 or so one night, the fresh water tank under the dinette never froze, the RV was parked next to the Fire Chief's house, so they used the bathroom inside for showers, neither of the tanks needed to be drained before they left, no insulation under anything in that 1975 RV. (before basement designs too). Once they traveled far enough south, they where able to drain the tanks, and made it back to California sagely.
The water bed heaters might work OK, but also need to have there thermostats in a location where they can tell how warm the tank is, and shut off before going over say 100F. Probably not a problem in 0F weather though, even if there is R-4 insulation under it, and then the R-0.5 underbelly plastic insulation. Yes two layers of plastic with a still layer of air 1/3" thick is insulation.
I would also highly recommend a Olympic Catalytic Safety Heater. I leave mine on high if it is below 45F outside, and will cycle the furnace on enough to keep it toasty warm inside - about 70F. Yes I have to leave a roof vent open about 1/2" and the window open a little bit, but the Catalytic heater is quiet, will not consume any 12 volt power, and at 6,000 Btu's will run 15 hours on one gallon of propane.
Did you think about running hot water from the outside shower or another source into the fresh water tank? Heat that fresh water tank to say 70F. That will be my plan to be able to take long and warm showers. I have a adapter in my bathroom sink where I can hook up a garden hose, and then can run water heater heated water into the fresh water fill, 6 gallons will warm my 100 gallon fresh water tank a little bit. 6 gallons at 140F will warm a 40F tank with 60 gallons in it by about 10F. Do this 10 times, and you will have the tank over 100F. While it only takes 2 minutes to run the 6 gallon tank cold, then 30 minutes for it to take reheat the cold water again, do this for a couple hours, and the tank will be toasty warm, and not freeze, and keep the other things nearby from freezing.
I just bought a L-5 Ecotemp portable tankless water heater, to warm my fresh water tank. I can use it to heat 1 gallon per minute from about 45F to 95F, so I am using it to warm the water in my fresh water tank from 45 to about 75F, and I am enjoying really long showers this winter. Priceless! Well actually it cost $120 from Amazon.com It used 37,000 Btu's per hour, about 1/3 gallon. It will heat about 100 gallons in a hour from 45 to around 85F. It is designed for things like camping without a RV, and being able to take a shower, or wash horses outside with warm water. It would be especially good to wash the dogs in warmer weather, yet useless in 100F weather in Phoenix where heating the water is not required.
Next time you are getting ready for a winter trip, try filling your fresh water tank from the washing machine hot water line. Sure you will quickly drain the home water heater of it's 40 gallons of 120F water, and it will drop down to about 60F while filling a 75 gallon tank, but will fill a 40 - 50 gallon tank full of very hot water, so you would be best to add about 10 gallons cold then add 30 - 40 of the hot stuff.
When you lost fresh water flow, it might have been the pump housing that froze. CHeck it for leaks, just in case. Putting a 800 watt electric heater near the pump, set at around 55F is what I had to do in Portland Oregon when I was living in my RV in January. It worked, and I was able to plug that into a separate power receptacle at the RV park. I only have a 30 amp service, so was challenged to not trip a circuit breaker while still running 3 electric heaters in the RV to keep it warm.
At the time, propane was $2.50 per gallon, while the same 80,000 Btu's from electric heaters was only $1.98 at 9 cents per KW. Running a gasoline generator is probably closer to $0.30 per KW power.
* This post was
edited 01/26/13 02:00am by Golden_HVAC *
I used a water bed heater under my fresh water tank on my old Okanagan fiver for years. In the late fall I would leave it as long as I could without winterizing and turn on the heater during the week in case it froze before I could get back out on the weekend. I froze the trailer solid once before I put this heater in but never again after I did.
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I was looking through some old posts, and came across this picture, it was wind damage, and the local winds at over 55 MPH make it a convenient way to look at what the tanks might look like under a typical RV. This one looks like a toy hauler, with the forward black tank, then the smaller outlet pipe to what should be the grey tank, and water and towards the back a fuel tank is my best guess.
So it might give you a idea of what you will find once you remove the underbelly cover. A few people have posted they have no idea how the heavy water tanks stay under their RV's without falling off onto the road sometimes, without good reinforcements to support the tanks. They wrote in about using some aluminum straps under the tanks to help assist with whatever the manufactures said was adequate in the original design.
A 50 gallon waste tank can be full of 400 pounds of water! Take it over a few pot holes, and that is bounding up and down with 800 pounds of force, or more.
Looking at the instructions for installing the pipe heaters, they state that they should be wrapped with fiberglass insulation.
Has anyone used a different material sucessfully?
I was looking at what Home depot had to offer. They had 6' long tubes made of some sort of black flexible foam. It is cheap at about a buck a tube and would be a snap to install.
I know that the pipe heaters have been used by many here on the water supply hoses....Even though that is not recommended either.
Beware to make sure the pipe heaters are for plastic pipe and not steel pipe. The ones for steel pipe could melt the plastic pipe.
I believe that type is a constant on variety.
All the ones I am looking at turn on at 38 and off at 45. They never get very hot 140-160 is what I have seen in the specs.
And they are stated as usable on plastic pipes...
Interesting is that even at this low temp, they are said to prevent freezing (when insulated) down to -40, -50.
If you get some 2' wide reflex insulation, you can wrap this around the bottom of your trailer while at a show, and then put it away when you are ready to leave. Sure it would take 75' to wrap all the way around a RV, but that will fit into a large 30 gallon trash bag for storage, it rolls up pretty tight.
Then it would be practical to have a electric heater under the RV, to keep that space over 32F. This would keep all the tanks warmer.
By filling the fresh tank with hot water, it might be enough to keep everything plenty warm enough when camping at 5F.
Also put a 100 watt light bulb near the water pump, or a small heater in that area, to keep it from freezing. A couple of thermometers with remote readouts can give you a good idea of the temperatures near the water pump and holding tanks. At least you can return to warm Phoenix where the tanks can thaw out and warm up to dump them after a day or so.
My PLAN-B for these such times is to quickly do winterizing using the AIR BLOW OUT METHOD. I can do this is around 5-minutes for the fresh water tank and lines. The next day when the sun comes back up then I can start using things again. The bad part of this PLAN-B however is being out in the woods somewhere without fresh water being available. I usually have 5-gallon of water on the trailer somewhere so I can just sit that inside the trailer over night to keep from freezing...
Was looking at the heated water lines on here a few weeks back when this subject was on-going then. Sounds like a good plan...
This might be another good candidate for the Hydronic mods to the 6-gallon hot water heater and route some hot water lines around the tanks.. SMKETTNER from Calif is doing this now. Doesn't take alot of propane to keep the hot water heater going all the time if it is in a closed loop... You might get away with two or three regular hot water fed baseboard heater strips and just heat up the area area under the trailer with the membrane installed...
Speaking of REDNECK heaters My daddy was road commissioner back in ILL way back then and his plan of attack for the Caterpillar was to build a bonfire under the oil pan to heat it up so he could get it started haha... Sometimes you gotta do what you gotta do...
* This post was
edited 02/05/13 09:21am by RoyB *
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting Roy - Carolyn
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My buddy had to drive to Colorado to pick up a old over the road truck that someone working for the company quit, and parked on the side of the road in the winter. He went to the bus station in the town, and then went looking for a tow truck to work on jump starting the truck, and dig it out of the snow.
Most tow truck drivers said no, but he finally found one. $100 bill in 1972 was a good thing for the company to say you can pass out two of them to get some help. (that is like saying $2,000 today). They got the truck started by pouring diesel on the snow below it, and lighting it on fire. Then toss bits of snow on the areas that where getting a little to warm. Finally after warming up the engine enough, they where able to crank it over with a set of huge jumper cables. The tow truck driver was starting to leave, but the big rig was not going into any gear, so back to pouring diesel under the transmission this time, until it would go into gear. At least the cab was starting to warm up 1/2 hour later.
Then kept it in one gear for about 3 miles (only about 6 MPH too) until it finally was warm enough to start shifting. Never again! ! He never shut off his truck in the winter after that.
Back to your hydronic solution. It seems pretty simple to install a PEX line in the kitchen, where you can return hot water from the kitchen sink (install a new valve) through the areas you want to keep warm, then dump the water back into the fresh water tank. It will serve to warm the areas the line passes, as well as heat the fresh water tank, and keep the pump full of warm water too.
If you run 1 gallon per minute of 140F water out of the line, into the tank at say 90F, it wil drop 50X8 pounds - 400 Btu's of heat into the space, and about 300 Btu's into the water tank each minute. After about 10 minutes the water heater will be cold, so shut off the pump for about 1/2 to 1 hour. Probably about 25 - 30' of 1/2" PEX tubing would get the job done.
My buddy put a gallon of cheap wine into his fresh water tank when he was visiting the Winter Olympics in New York, back in 1980. Back then, no motorhomes had basements where the tanks could be heated. Bounder started that trend in 1986!
* This post was
edited 02/05/13 10:54pm by Golden_HVAC *
My project is about 3/4s complete.
The waterbed heater idea wouldn't work for me. The way my tank is made, it doesn't have a flat bottom. In fact I don't even think the Ultra heat ones would work..I still think it can work with the right tank.
Removing the underbelly showed somethings that needed fixing.
My FW tank was bulging down like a pregnant sow, and one of the support brackets had a broken screw on one side and a busted weld on the other. So I welded up a new support system out of 1" square tubing ans 1.5" angle iron..It's not going anywhere now.
While I had it opened up, I ran some wire for a dedicated outled for the 5.0 CF freezer we carry on the rear rack. I also installed a new seperate cicuit (non invertor powered) just for the heat tape I was installing. It took a total of 13 heat tape segments to do everything.
They each have their own outlets now, so no extension cords will be used. The HT circuit is controlled by a switch, which energizes the GFCI. All lines are insulated.
After some thought I decided to upgrade the insulation. I am installing polyisocyanurate insulation 1" thick 6.5R value. The inside of the frame rails and running across the bottom will get this. To protect it, I am going to reinstall the reflectix and coroplast that the TT came with. I am basically making a large cooler out of the underbelly area. There was one small heat vent towards the rear of the underbelly. I enlarged it to about 2" and made another on up front to warm the FW tank.
I am considering a 3rd vent in the middle. Might wait on that as since I am sectionalizing the underbelly to a maximum of 4' sections...Access will now be easy.
The underbelly is turning out so good, that the pipe heaters may never be needed.