Adding tank heaters for winter use.

[JoshuaH]

My wife is an ER nurse, obviously not the safest profession right now. She has been using our camper (Wolf Pup 16HS) for isolation when needed, however now we are heading into winter.

My question is, if I add tank heaters, would this camper be safe to use in below freezing weather if needed? How cold can you still go safely? I realize wind would be a big factor as well.

Is it better to use a heated fresh water hose or to just fill the fresh water tank and put a heater on it as well?

Will I also need to somehow heat the drain valve and pipe or will the heat from the water in the tank transfer to the water in the drain pipe and keep it from freezing as well?

Any and all advice for setting up this camper for below freezing temps is very much appreciated. I want to have it ready to go so if she gets exposed or worse gets Covid the camper is ready to go for her on short notice.

Thanks!

[JRscooby]

I haven't checked on price in a long time. But if not moving the trailer you might use bales of straw to keep air from going under the trailer. Years back, I saw a TT with straw bales stacked up all around up to above roof level. I could see a tarp over it, was told there was foam board under the tarp.
(Couple living in it while rebuilding burned house. I was delivering material)

[profdant139]

For whatever this is worth, I'm using Ultra Heat cables (not a tank heater) on my small trailer -- the cables are thermostatically controlled. They draw about 2 amps, using 12V power, at 30 degrees.

We have used them successfully down to about 20 degrees (without hookups). At 15 degrees, we did get some icing. Not a full freeze, but still worrisome.

I should add that I wrapped the cables and the pipes with a few layers of reflectix, in an effort to hold down the heat loss.

[CavemanCharlie]

When I use my TT in the winter time I just leave it winterized. Then I use a porta potti for waste and a tote in the sink for washing hands ETC. I am just using it for a weekend at a time though, not for long time living.

[pianotuna]

The ultra heat site suggests:

"correctly sized heat panels to RV holding tanks down to our design benchmark of -11°F (-24°C)"

[JoshuaH]

Thanks everyone, I really appreciate the input. This is obviously more than I realized, will have to give this more thought.

[time2roll]

Small tank 4 amps 25g
Medium tank 10 amps up to 55 gallons
Large tank 12 amps up to 75 gallons

I have 4 medium tanks = 40 amps. OK the voltage rating is 13.5 and would draw less as the battery sags to 12 volts and below. That would also give less heat and maybe the large pad is needed. My trailer came with a 55 amp converter so 40 amps will be near max. Add a few 12v pipe heaters and you could be on battery power.

OK they may cycle some in moderate temperatures. However at 0F and below I would assume near continuous power is needed. Especially on battery power producing less heat or if the pad is undersized some.

https://www.annodindustries.com/shop/shop/premier-heaters-and-warmers/rv-and-marine/rv-tank-heaters....

[pnichols]

Here's the answer to my own question above:
https://www.ultraheat.com/ultraheat-rv-tank-heaters

As you see from the 12V tank heater specifications, their current draw is way low at 4.1amps to 11.8amps. As such, 12V tank heaters should be "no problem" for emergency use in drycamping, since due to their cycling On and OFF, total amp hour draw-down of RV batteries is not too bad at all.

[pnichols]

SDcampowneroperator wrote:
I have to comment again, concerning tank heaters. 12v wont do, as the amperage they draw is 10 times 120volt. 3 heaters, @ 250watts ea., is 6 amps at 120v, 60 amps at 12volts! Your battery would be dead in minutes, as well your converter would be maxed out trying to power only the tank heaters not to mention the rest of the house.

I have installed tank heat on 2 of my units, with one a 1997 HR 32WFS , I used old waterbed heaters with their thermostats set at 45f ( 8c) then ran the power cables to where I could plug them into my inverter when on the road or dry camped ( with the truck running or when power went out ) or into an outlet when hooked up to power( hydro to us dual US and Canucks ) Worked great to temps below -40 c or f
On the first one, a 1987 Award Columbia which had all exposed tanks I used 5 watt/ ft. heat cable glued to the underside of the tanks around the pump and dump valves, then spray foamed the entire underbelly tanks and all. That worked OK also but required proactive attention as it was not automatic thermostatic so I had to pay attention the temps outside.
In either case the trick is to dump only when the waste tanks are full or if not heated then use copious water, sinks full, flush full bowl 3 times amounts of water to carry the wastewater to the drain. , be certain your waste hose is graded if not heated. Most of all, vent and dehumidify the house or all your attempts at keeping warm will backfire because the moisture WILL condense in your walls rotting and ruining all your attempts leaving you with a rotten unheatable,unliveable hulk.
Seen that, a new Airstream interior destroyed in one winter in Coronach, Saskatchewan, Canada

What you say is only true if 12V tank heaters are the same wattage as 120V tanks heaters ... which they may not be. Is there an Internet link to the specs of 12V/120V tank heaters showning how many watts each model consumes?

I've been down under my tanks looking at it's 12V heaters on the bottoms of the GW and BW tanks. The wires to these 12V tank heaters don't appear to be anywhere near high enough gauge to carry the currents that you're mentioning.

Regarding battery amp hours consumed to power 12V tank heaters ... tank heaters cycle On and Off as they're opperating, depending upon how much water is in the tanks and the air temperatures ... so their current draw from the batteries is not constant.

I prefer 12V tank heaters for emergency drycamping insurance. When hookup camping, I assume that they wouldn't be offered if common RV converters couldn't keep up with their power needs.

[pianotuna]

SDcampoweneroperator,

Please consider adding your comment to the winter camping thread under the full time forum.

Thanks!

[SDcampowneroper]

I have to comment again, concerning tank heaters. 12v wont do, as the amperage they draw is 10 times 120volt. 3 heaters, @ 250watts ea., is 6 amps at 120v, 60 amps at 12volts! Your battery would be dead in minutes, as well your converter would be maxed out trying to power only the tank heaters not to mention the rest of the house.

I have installed tank heat on 2 of my units, with one a 1997 HR 32WFS , I used old waterbed heaters with their thermostats set at 45f ( 8c) then ran the power cables to where I could plug them into my inverter when on the road or dry camped ( with the truck running or when power went out ) or into an outlet when hooked up to power( hydro to us dual US and Canucks ) Worked great to temps below -40 c or f
On the first one, a 1987 Award Columbia which had all exposed tanks I used 5 watt/ ft. heat cable glued to the underside of the tanks around the pump and dump valves, then spray foamed the entire underbelly tanks and all. That worked OK also but required proactive attention as it was not automatic thermostatic so I had to pay attention the temps outside.
In either case the trick is to dump only when the waste tanks are full or if not heated then use copious water, sinks full, flush full bowl 3 times amounts of water to carry the wastewater to the drain. , be certain your waste hose is graded if not heated. Most of all, vent and dehumidify the house or all your attempts at keeping warm will backfire because the moisture WILL condense in your walls rotting and ruining all your attempts leaving you with a rotten unheatable,unliveable hulk.
Seen that, a new Airstream interior destroyed in one winter in Coronach, Saskatchewan, Canada

[pianotuna]

Time2roll has done lots of cold weather camping. Listen to him carefully.

Power outages do happen--so I keep my furnace on ready to jump in to keep things from freezing.

[time2roll]

If there was no electric power or you experienced a loss of electric power I would be far more worried about keeping the furnace going than the tanks freezing.
Collectively the heaters could draw 40+ amps from the battery and shut down the furnace with a dead battery.

[pnichols]

I would go with 12V heaters so that in the extremely rare situation in which you were caught having to drycamp in the extreme cold you could still keep the tanks heated.

Whenever on hookups camping in the extreme cold, the built-in converter will of course keep the batteries from being drained while powering the 12V tank heaters.

12V heaters for your tanks is the more versatile approach.

[time2roll]

JoshuaH wrote:
I would want to go with 120V heaters.

My tanks are completely exposed. I'm in central Missouri, we don't often get really cold weather for very long periods, worst case if needed she could check into a hotel for a few days. I'm just wondering if I added heaters what temps I could safely do.

I would guess you could go to 0F overnight fairly easy if you add heat to the exposed areas. Going to burn a lot of propane, consider getting an extra cylinder or two.