would a reptile heat bulb underneath keep things from freezing?

[jls]

would a 150W Reptile Heat Bulb and Digital Thermostat Controller Combo Set placed under the van keep my tarp-skirted van's water tanks & lines above freezing on nights that dip into the 20s F.? (or maybe a couple 80W or 100W ones would be better than 150W?)

anyone already been down this road?

[SteveJ]

That's a slick package. I would think it work fine with a tarp, assuming you can keep the wind out.

If for you get colder you could run the van engine for a few minutes to create heat in the exhaust system.

[avanti]

Originally Posted by SteveJ

If for you get colder you could run the van engine for a few minutes to create heat in the exhaust system.

Don't do that. Running an engine without letting it get up to full operating temperature is not at all a good thing. And, don't underestimate how long that takes, especially with a modern Diesel engine, which may NEVER get up to temperature at idle..

[<<B-Guy>>]

My feeling is that it may not be enough - I'd be inclined to use the type of small ceramic cube heater that we use inside the van - 1500W.

[Belzar]

150 watts is not much heat - just a light bulb. If you have electric available, a ceramic heater costs less than $30. If your skirting keeps wind out that will probably be enough.

[jls]

i've been shying away from the ceramic heaters with fan because a couple reviews noted they caught on fire! they are a higher wattage plus the fan (maybe those were a factor?) but they also have a heat coil embedded in ceramic like these reptile ones, so i'm not really sure how much more of a fire hazard they are.

[SteveJ]

Originally Posted by avanti

Don't do that. Running an engine without letting it get up to full operating temperature is not at all a good thing. And, don't underestimate how long that takes, especially with a modern Diesel engine, which may NEVER get up to temperature at idle..

I would agree on an ongoing basis but I don't think occasionally doing this is a problem.

That said, upon thinking on this, this van will likely not be moved, so idling not the best solution.

[avanti]

Originally Posted by SteveJ

I would agree on an ongoing basis but I don't think occasionally doing this is a problem.

Well, even a single instance of an engine start not followed by a warmup will pump water vapor from the air into the engine and exhaust, where it will condense and remain as liquid water until the next start. How serious this is is dependent on the relative humidity at the time.

[pomerlo]

My feeling is.... if it is well protected/skirted against the wind then yes it would be sufficient. For water to become rock solid frozen to the point where it could expand and crack your pex pipe the temp should go lower than 20's.

I would make sure the wind cannot lift the skirt in any ways and for an extra security, why not put some Styrofoam or pink fiberglass insulation squeezed around your van.

[avanti]

Originally Posted by pomerlo

For water to become rock solid frozen to the point where it could expand and crack your pex pipe the temp should go lower than 20's.

This is not accurate. When water freezes, it freezes. It is a phase transition--it doesn't freeze "more" when it gets colder. It does get somewhat harder, but it does NOT continue to expand. The danger point is exactly at the point of freezing, which is 32 degrees F under normal conditions. After that, as ice gets colder, it contracts just like any other solid.

P.S. -- Pex pipe is rarely damaged by freezing. It is the plastic and metal fixtures and fittings that are most often damaged.

[pomerlo]

Yes Avanti I totally agree with you. The expansion is at max at around freezing point.

I should have phrase that differently. I was talking about the outside temp.
So in short, If the underbody of the van is isolated somehow and an heat source is set up there and the outside temp is not gowing lower than the 20's
then the water should not freeze rock solid in his pipes.

Thanks for pointing that

[hbn7hj]

Should be OK with the interior kept at 55F with a skirt without a heat source. You can always try it and see.

[Deano]

Just curious, why not drain the tanks and lines?

[jls]

I live in coastal california so i plan to use the vehicle throughout the winter. it's just a few times a year temps dip below freezing so i'm trying to come up with a solution for those frosty nights.

[otr]

I am skeptical of keeping it from freezing in this situation. remember, air will get in around the wheels, engine, on our 2000 190, the water outlet from the fresh tank is just inside the drivers rear wheel.
Here in Vermont I almost missed my garden hoses the first cold night we had this fall. I ran out at about 9PM and pulled them from the faucets, and the water was slushy consistency, it5 was 27 degrees.
As another poster said, the pex will "probably" be fine, but the fittings "may"crack.
If there was a way to tarp the van and blow heat under it, maybe, but it seems to be very risky to me.

[DAWg134]

Freezing water conditions involve not only temperature but also duration - the lower the ambient temperature, the less time it will take for the water to reach 32 degrees. If you're located in coastal California, chances are that the temperature only dips briefly below 32 degrees - this is much different than parts of the country that experience sustained temperatures below freezing. If you can protect the most vulnerable components such as exposed exterior pipes with insulation to slow the heat transfer, then chances are you'll be okay. It all depends upon how cold for how long and also how warm during the day.

[Nic7320]

Heat lamps can create a hot spot, and can do exactly what you're trying to prevent -- damage your tanks! Best to use a heat blanket, a pad that distributes heat evenly.

There's an RV surplus store in Quartzite, AZ that had 12 volt heat blankets for $5 or $10/ea. called Gamblers RV. Also check with a place in Corona, CA on Railroad St. -- Walts? I forget the name. And there's aways Amazon and eBay.

My RV started life in NY state, so it came with "Arctic Pack" heaters. Haven't had to use them yet, but someday I'll need them!

[jls]

Thanks for caution. Noted! The heat mats i found previously were quite a lot more expensive than this ceramic bulb. I also figured i'd need a way to keep the mats off the ground so wouldn't be just heating the ground. i'll take another look at how to make this work.

This Thermo-Cube seems ideal for turning on some heat under the van when the temps reach 34.

A couple nights ago the temps went to 28 at Pismo Beach (central CA) which was quite a bit colder than forecasted. I ran my hot and cold water taps a couple times to keep things flowing but did wonder about the tubing between the city water connections and other things that might not be part of the flow.

[wny-pat]

Originally Posted by jls

i've been shying away from the ceramic heaters with fan because a couple reviews noted they caught on fire!

Ceramic heaters are not created equal. There are good ones and bad ones. Never buy a bad one. Read the reviews. Search out all the reviews. Find a good one!!! Then remember to operate it safely!!! Never place anything flammable near it or where something could fall on it. That goes for your furnace too! That is how most RV fires start.
You don't say what type of RV you have, just that you have skirting around it. You live in coastal California, so I doubt you have to worry unless you are talking northern California. A couple hours with temps below 32 degrees are not going to hurt anything. It is a hard freeze over several hours that you have to worry. Some of the newer coaches have the tanks in insulated compartments. And if you have a diesel, they are notoriously cold as internal combustion engines go. I have driven some here in the north that would not put out any heat into the cab of the truck. A gas engine tends to be warmer once up to operating temp.
I use to use a ordinary old fashion 60 watt light bulb in the utility compartment of my old Class A as a safety measure, but I always winterized everything. I also left it plugged in to maintain the batteries and ran a cube ceramic heater on a low setting to keep the chill off in the coach, just enough to keep it above freezing.
If you are in a newer coach that used PEX plumbing lines, you should have to worry about the lines. I have a friend who is a plumber who has filled a couple PEX lined filled with water and capped that he keeps in the freezer. He always takes those frozen PEX pipes with his when he is estimating a new job, to show the customer how strong PEX is and how well it handles freezing.
I tried the Thermo-Cube you mentioned, but was in that 8% group that had bad luck with them. Mine never worked. I tried two of them. Wondered it the people who had good luck never checked on the operation once they set them up. Maybe they are a better product today. Your water pump should be inside the coach I would think. That would be one of your problem area.
Good luck and hopefully it doesn't get as cold there as it already has here!!!