TT ability to withstand the cold.

[BeerBrewer]

We just got back from the RV show in PA and I've got questions about the best way to protect the tanks and piping underneath the TT from freezing. I understand that even though some RVs claim to be 4 season campers, they usually aren't. Now we're not looking for, nor do we expect a TT to function up north in the dead of winter, but were I'd like to camp in the fall you can get a day or night where it drops well below freezing and I'm worried about the consequences and the best way to protect the TT against it.

Some of the manufactures claimed that they heat the underneath area of the TTs. Some used forced air, some claimed to wrap the pipes and use heating pads. Do these methods really work? Some claimed to use an abundance of insulation. Some also claimed to have tested their TT to 15 or even zero degrees. Ca I trust that or is this all just marketing hype?

Is there anyway that I can climb underneath the TT and add some extra protection my self?

Thanks

[Community Alumni]

Earlier this year I had my trailer in -10°F nights and 8°F days. My trailer has a heated underbelly and it did ok. The furnace ran pretty much all of the time and we had a space heater going on the inside. The only thing that froze was the low points because they hang below the belly and the regulator froze once.

[myredracer]

...

[myredracer]

Having just had our underbelly coroplast off, the design of "heated underbellies" is ridiculous besides being very inefficient. There's a 2" layer of batt insulation under the tanks which gets squished and thus reduces it's R-value plus the insulation blocks air flow. The only way "heated" air gets from the front of the TT to the rear is via a small gap between the tanks and I-beams. It would be interesting to know what manufacturers do a better job, if at all, like maybe Northwoods products, OutdoorsRV, Nash & Arctic Fox. (These also have thicker walls.)

I also know they do a poor job of insulating ceiling cavities in TTs. I've seen the ceiling cavity in 3 TTs we've owned and it's sad what they do. Our current TT has an arched ceiling and because the joists taper down at the outer perimeter, there's no insulation for up to 6" in from the exterior wall. Lot's of voids too.

RVs in general aren't designed very well for cold weather. The exterior walls and ceiling assemblies have an exterior skin which is the moisture barrier/retarder and is opposite to buildings. Warm moisture-laden air migrates to the exterior surfaces and condenses on the interior side which can lead to mold, rot & delam. It's important to remove the moisture-laden air by cracking open some vents and windows or using a dehumidifier. Venting air out of course means you're losing heat and the furnace will need to run more.

[shum02]

Huntindog wrote:
My present TT came with the heated underbelly. Had a cold snap shortly after getting it. We lost flowing water at 5 degrees. This was with the furnace running non stop with the roof vents wide open to keep us from baking.

Here is a link to the thread about the mods I did to improve it:Cold weather mods

Basement water lines are the first to freeze. Running heat trace on them solves that problem.

[Huntindog]

My present TT came with the heated underbelly. Had a cold snap shortly after getting it. We lost flowing water at 5 degrees. This was with the furnace running non stop with the roof vents wide open to keep us from baking.

Here is a link to the thread about the mods I did to improve it:Cold weather mods

[camperdave]

My waste tanks hang out in the open. But the fresh water system is all inside. I've camped in the snow a few times and had no issues (other than using lots of propane for the heater, and gas for the generator). The dump valves were frozen, so I just waited till I got home to dump. If I were staying long term i'd have a poopsikle problem.

[RobWNY]

It's my understanding that most RV Manufacturers believe that their "4 Season" RV's means you can use them in the Northern United States and most of Canada during May, June, July and August.

[jamesu]

If it is supposed to freeze during the night, disconnect the outside hose and drain it so no ice forms in it. In the morning reconnect it. You’ll be fine. During the day if you are concerned about freezing leave the taps drippings like at home.

My present TT is a “4 Season”; my previous TT was not. Using the above protocol I have never had a problem in either late February or in early October, the outside limits of our camping schedule.

[Lynnmor]

RSD559 wrote:
I wasn't even thinking about the cold temperatures at night until our water stopped working. Everything in the trailer was fine, but the hose from the spigot had frozen solid.

Some campgrounds no longer rely on signs posted about disconnecting hoses in freezing weather, but instead shut off and padlock the hydrants.

[ppine]

You have to look under there and see what 4 season means.
Plenty of people in places like Alaska and Wyoming live in RVs year around. They figure out ways to make everything work in extreme temperatures.

[ktmrfs]

ours has the covered underbelly with "radiant" heating. E.G. no direct heat vent to the underbelly. I modified that slightly by pulling up one of the floor vents and drilling a 1/2" hole in the side of the vent to direct some air into the underbelly. Then I dropped a temp probe in the far end of the underbelly. underbelly stays well above freezing even in cold temps. And at night we set the heat to 45F, turn in on in the AM.

We've had nights well below freezing, with daytime above freezing with no issues.

the limit is likely the lowest average temp where the furnace can keep up with heat loss during the day and bring the trailer up to temp in the morning.

[shum02]

If you get a night of below freezing temps in the fall, in PA and have a factory covered and insulated belly with direct heating from the furnace you have ZERO to worry about.

If you are like me and camp in Northern Ontario at -22F for 5 days then you have something to worry about.

[wanderingaimles]

Any and all measures you mentioned can help to varying degrees in varying circumstances.
Enclosed underbelly for a first step, then decide on how youre to use the tt.
If you are using it in a campground, using all elec space heaters to warm you in the winter will not help protect your tanks as much as the furnace on a unit that uses some of the furnace heat to warm the tank areas.
Pad heaters are great, as are heat tapes on piping, but you have to have sufficient electricity to power them.
For a weekend trip, where temps may dip just below freezing in the evenings, most units claimed as "4 seasons" will be fine if you are keeping the interior at a comfortable temp. But once you go below freezing, time and temp are working in tandem against you, prolonged time can make even moderate freezing temps a problem.

[RSD559]

Our trailer has the heated underbelly. We were visiting family in northern Utah last November. I wasn't even thinking about the cold temperatures at night until our water stopped working. Everything in the trailer was fine, but the hose from the spigot had frozen solid. So I guess the heated underbelly works. An older trailer we owned had heat pads glued to the underside of the tanks, which would help them, but leave the connections unprotected.