leaving furnace on in winter?

[handn]

Here in Colorado, we winterize.
Running the furnace uses lots of propane. When winter camping, I go through a seven gallon tank of it in a few days
R.V. furnaces are not as reliable as home furnaces and the possibility of shutdown and freezing your rig is significant.
I winterize like markdoane, except I drain the water pump. It takes me about an hour and uses a half a gallon of r.v. antifreeze and I am not that handy. Just fill the tank and turn on the pump when you are ready to go camping.

[jcanavera]

Originally Posted by osolow

I am curious if anyone out there leaves there furnace on in the winter mouths, or if you turn them on if it's going to get extremely cold?

also how many people are lucky enough to store there A/S in a garage or building?

Nope, we winterize the trailer so how cold it gets is inconsequential. The only time we've used the furnace to warm the unoccupied trailer is when it's at home in the drive and we are early or late in the season with a night forecast for freezing temps.

We are extremely fortunate to have an indoor storage locale where the trailer spends it's idle time.

Jack

[nohillgrish]

As we use our unit throughout the winter, it get's winterized in late October-early November. All that means is that it gets a shot of antifreeze in all the right places, water and waste containers brought out of storage and put in trailer and three backup heating systems double checked. Winter camping has it's unique pleasures/challenges, but I just love a 12-month camping season. Would be nice to have inside storage, but we've not had any problems being outside.

[78GussyTX]

Wow, I am glad to live in Texas! I'm surprised AS has not developed some kind of plug-in electric option to keep things above freezing, like the diesel block heaters. As for -40 F or C, neither one sounds very hospitable to me!!

[Sky]

I winterize the trailer, but I still try to maintain a constant temperature of 40F inside. I set furnace to 40F and supplement it with a ceramic heater on very cold nights to conserve propane. I am afraid a cycle of freezing and thawing is not good for the joints throughout the interior (especially the wood cabinets).

I am guessing this costs me about $100 over the winter months that we are not snow-birding. Am I wasting my money?

[Inland RV Center, In]

Originally Posted by Sky

I winterize the trailer, but I still try to maintain a constant temperature of 40F inside. I set furnace to 40F and supplement it with a ceramic heater on very cold nights to conserve propane. I am afraid a cycle of freezing and thawing is not good for the joints throughout the interior (especially the wood cabinets).

I am guessing this costs me about $100 over the winter months that we are not snow-birding. Am I wasting my money?

Keeping the interior at about 40 degrees in the freezing weather pays huge dividends.

First of all that heat must come from the furnace, since it forces the heat near the water lines and holding tank(s), which prevents a freeze up.

Should the ambient temperature be forecasted to be below 10 degrees, then it would be wise to increase the interior temperature another 5 degrees or so.

Another wise step is to open all the cabinet doors that hide the water lines and other plumbing. That permits even better circulation.

That saves winterizing costs.

Oil or electric heaters have no way of circulating the heat around the water lines and holding tank(s).

Keep an eye on the propane level.

Don't run out of fuel.

Andy

[Silverhobby]

"That saves winterizing costs. Andy" --- Where I live, a couple of gallons of antifreeze, even installed multiple times, is CHEAPER than P R O P A N E !!

[jcanavera]

Originally Posted by Sky

I winterize the trailer, but I still try to maintain a constant temperature of 40F inside. I set furnace to 40F and supplement it with a ceramic heater on very cold nights to conserve propane. I am afraid a cycle of freezing and thawing is not good for the joints throughout the interior (especially the wood cabinets).

I am guessing this costs me about $100 over the winter months that we are not snow-birding. Am I wasting my money?

My gut on this is if the only reason is to protect the cabinets, you're wasting your money. Consider the fact that your cabinets flex big time when you are under tow, the temperature change that occurs is minor in the big picture. Also consider that any appliance has a limited amount of uses. Personally the wear and tear on your furnace is not worth the amount of flex that might occur with the joints. Especially in light of what goes on when you tow.

One final thought, if you consider the temperature varriance when considering flex, summer creates a much bigger temperature gap considering the temps in a closed trailer. My advice, winterize the plumbing and turn off the heat. You'll save money and lengthen the life of your furnace.

Jack

[Sky]

Thanks Andy and SH. I should be clearer in my question. I do have the trailer winterized. It has antifreeze in all the lines. All tanks are empty. Hot water tank empty. Traps have antifreeze in them. I am just concerned about expansion and contraction of interior parts during the daily temperature swings above and below 32F.

[HowieE]

Originally Posted by Sky

Thanks Andy and SH. I should be clearer in my question. I do have the trailer winterized. It has antifreeze in all the lines. All tanks are empty. Hot water tank empty. Traps have antifreeze in them. I am just concerned about expansion and contraction of interior parts during the daily temperature swings above and below 32F.

The expansion and contraction of metal is a constant over any range of temperature and not effected by the transition across 32 degrees F.

The expansion coefficient for 1 meter of aluminum is 2.3mm per 100 degrees F
so the effect at + or - 32 degrees is no greater that the effect at + or - 85 degrees.

[Gene]

I have seen furniture left in an unheated cabin in the Colorado mountains and it eventually starts to fall apart and warp from the expansion/contraction cycle. But it was pretty old furniture, the glue had probably dried out a bit faster in the dry climate and it was solid wood. So, if you have that kind of furniture, there may be a problem over decades. Even furniture kept in a house will eventually have dried out glue joints, sometimes in a few decades. High humidity can be a problem with furniture and the humidity can get pretty high inside when the trailer is being used.

Some Airstreams have solid hardwood cabinets. Some have plywood and soft woods. The partitions in our Safari look to be plywood and some fiberboard. For freeze/thaw purposes, the plywood and fiberboard is pretty stable dimensionally and will withstand the cycle better than solid wood. But how the cabinets are put together matters a lot—do the interior panels on cabinet doors "float" or are they glued, are the glues used stable for temp. changes, are the cabinets just stapled together, or glued with dowels or biscuits? Are drawers stapled or dovetailed? The glues used for the Formica countertops and dinette table may be a problem. I have had the edge banding loosen in the bathroom. The solution is to iron it back on. Use a low heat. Do not use an iron that your wife is uses—she will not like that because there can be some residue on the bottom of the iron (I speak from experience). The fake wood grain on the partitions may be glued on with contact cement. That cement is pretty intense, so I imagine it won't separate. The vinyl floor is probably glued to a plywood subfloor. I don't know if the vinyl moves more than the plywood, but I can see it could fail eventually. All these potential problems exist in houses, but take longer to manifest. Houses usually get remodeled before cabinets and other built-ins fail so we don't think about it. I read on the Forum that the cabinet work was much better years ago and maybe we will see problems much sooner now.

For the record, the Safari stays outside. We considered a shelter and then decided it wasn't worth the investment since we won't stay here forever. No problems after nearly 14 months. Since I keep reading the cabinets are simply stapled to the walls, that concerns me because I can't imagine how that would be. Big staples into wood are fine—basically 2 nails—but stapling to the frame? If there were a staple into metal I'm wondering what expansion/contraction does to that, but I can't imagine stapling into metal though I'm sure it can be done.

The question about the freeze/thaw cycle is an interesting one and I hope to promptly forget about it so I can worry about my tires exploding, corrosion, batteries and everything else that I have discovered I can worry about since we bought this thing.

Gene

[phoenix491]

We live in north Texas, so we don't have to worry much about long stretches of sub-freezing weather ... We've been below 32 for the past few days, so I've kept a small ceramic heater running in the trailer, with all the cabinets and closets open.

It's only a 20' trailer, with new insulation, so it traps heat incredibly well. In fact, when we camp in the winter months, we can only keep that little heater going for an hour or two at a time, or it will get unbearably hot. I'm not sure what the hit to our electric bill will be, but it's worth it to me to have a little peace of mind.

[1cericks1]

Well I didn't get to winterizing my airstream yet, but did a little experiment last night. The temps here in golden dropped to 16 degrees F most of the night. Now it's 25 degrees. I've had the furnace on at 42 degrees and have been regularly monitoring the water temperatures (simply by running water into a pot and measuring the temps with our digital rubber ducky baby bath thermometer). I'm surprised that the water has not dropped below 40.

If the water get's below 35, I was planning on running the hot water from the external shower back into the fresh water fill to increase the temp of the water tank. Then every few hours I'll turn on each tap for a few seconds. Unfortunately I don't have an easy way to run hot water from the house but since the fresh water is about 1/4 full, I figure 6 gallons of steaming hot from the airstream should keep the water well above freezing range. Overall I was really surprised that the furnace is keeping the water tems so warm.

[Gene]

Since we haven't finished traveling yet, I haven't winterized. I'm keeping the heat pump set at 40˚. In the upper 20's, it switches automatically to the furnace and starts heating the water tanks. Unless the temp stays a few degrees below freezing for days, it won't freeze solid—but if the low temp is 28˚ or 30˚, it will quickly warm up, especially in Colorado, so I wouldn't worry too much. The heat pump won't warm the tanks, but it does keep the pipes warm enough; the furnace warms the tanks when it turns on. I leave the potable water tank close to full because it takes longer to start freezing with a lot of water storing the day's heat—this is unproven, but might make sense. I do not want it full because if all goes wrong—neither heat pump nor furnace works—the frozen water will expand 11% and burst the tank. Who needs that?

This automatic heat pump to furnace feature is only on later models. The thermostat can go to 40˚ and that's where I set it. I use the heat pump because it doesn't use any propane and I want to have some when we leave in 10 days.

When traveling when it's cold, sometimes I use the heat pump and sometimes don't. It's noisy, doesn't run as efficiently in the 30's, and does put wear on the unit. When it's no going below 30˚ at night, we use a small ceramic heater—efficient, quiet, and uses the CG's electricity. If I wake up during the night, I may turn on the furnace.

I think your experiment, 1cericks1, proves the furnace works pretty well at keeping the temps very close to the thermostat setting.

Gene

[2airishuman]

Originally Posted by 1cericks1

... I was planning on running the hot water from the external shower back into the fresh water fill to increase the temp of the water tank. Then every few hours I'll turn on each tap for a few seconds...

hi 1'

imo trying to transfer hot water to the fresh tank is not wise, a lotta work, will expose bits to freezing and the net benefit is minor.
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MANY OVERESTIMATE the approach a/s used to 'warming/insulating' the plumbing, here are the basics.

-MOST of the pex pipes are ABOVE the floor and warmed by interior heat, this is why the FURNACE or space heaters protect the PIPES...

-the water PUMP is generally located INSIDE/ABOVE the floor in an interior space with heat ducting NEARBY...

-the fresh tank has ONE duct from the furnace directed toward it, but the tank is poorly sealed/insulted from the outside.

but the WASTE tanks do NOT have ducting (my understanding) or insulation beyond the metal belly pan and 1-2 pieces of styrene spacers...

-the water heater is encased IN styrene/foam...

-so the real items at risk (on modern units) are ANY exterior pipes, AND the DRAIN pipes/VALVES on the tanks...

-AND THE TANKS ARE AT RISK in really cold temps, or at the filling/drain connections, EVEN WITH THE HEATER ON...
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IF you have a good supply of lp gas, and electricity AND are comfortable leaving the furnace ON...

-set the furnace to 40 something.
-open all of the cabinet doors to circulate air
-FILL the fresh tank to at least 80%.
-DRAIN the external shower fixture and disconnect ALL hoses
-turn ON the water heater (gas or electric) unless it has been DRAINED of water.
-turn OFF the water pump
-OPEN the faucets in the lav and galley (BE SURE THE PUMP IS OFF)
-DRAIN the black and gray tanks AND add ~1/2 gallon of rv ANTIFREEZE to each (this will protect the seals/valves from freeze/thaw stress
-OR make sure the black tank has a lotta crap in it and there is a LOT of soap and stuff in the gray tank (this will lower the freeze point)

these steps will generally keep the INTERIOR water lines and tanks from freezing down to the 20s....
______________________

below 15 the fresh tank may STILL freeze at the drain valve, so EMPTY it and/or OPEN the drain valve.

providing the AVERAGE of daytime times (warmer) and night temps stays ~ in the mid 30s this is effective.

ONCE the daytime highs are freezing and night colder, the furnace need to be turned UP, insulation or full wintering is needed.

and a LOT more lp gas will be used.
______________________

i have used the steps above WITHOUT problems for many years while camping or in connected storage, down to about 5-10 F.

below 10 things OUTSIDE or the fresh tank can freeze, unless the furnace is UP THERE (60-70s)...

IF electricity is available 2 space heaters will help (and keep the furnace from cycling ON so much) with the interor...
______________________

ALL of the above uses a LOT of btus and is really just a temporary solution to iced water...

the definitive solution is a change of latitude...

cheers
2air'

one last generalization n analogy about this...

the PEX piping has some tolerance to expansion/contraction but the JOINTS are copper and at risk.

water EXPANDS and CONTRACTS around the 'freeze point' and this issue is different than HARD freezing (mid 20s and lower)

just like the human body, it's the stuff at the EDGES that can be harmed even if the interior is ok...

think about frostbitten toes and noses and cheeks and ears happening even when the guts are warm...

[Ag&Au]

I heated (to 55 degs F) an 8 x 12 semi insulated greenhouse with an RV furnace all winter for several years. I had a 12v battery with an automotive battery charger in the greenhouse. These are the things I learned.
You need a spare furnace to swap out if the primary one requires maintenance. You need a remote reading thermometer with a loud (loud enough to wake you at night) settable alarm in the house. You need a backup heating system if the power is out long enough to exhaust the battery, or to keep the heat on while you swap furnaces. I used a gas bottle top mounted propane unit. You don’t want to find the need to winterize your trailer when there is a blizzard going on. Plan on frequent trips to get bottles filled.
We finally solved the problem by adding a sun room to the house to store the tropical patio plants in the winter.
The bottom line is - I would not want to rely on the furnace to keep my AS from freezing in the winter. In my opinion it is expensive, time consuming and risky.
Regards,
Ken

[Gene]

The trailer is not made for winter—insulation is not very good and single pane windows help transfter heat outside. Models with panoramic windows are especially prone to this (I know from experience, they look cool, but…). When it's really cold and propane is disappearing fast, keep curtains and blinds closed and go to an RV store or Lowe's and buy some Reflectrix. Cut it to the window sizes and use Velcro to attach it and it will reduce heat loss (or A/C cooling in summer). If you want to look out the windows, it's easy to remove.

Gene

[Mike Leary]

Originally Posted by CrawfordGene

The trailer is not made for winter—insulation is not very good and single pane windows help transfter heat outside.

Nor a mo/ho. We're heading out next week, moving south for the winter.
We carry two liquid-filled radiators; fore & aft....quiet and warm.

[1cericks1]

Thanks for the advice. I do plan to winterize it, just hadn't got to it yet. I guess I was just surprised by how well the furnace worked in keeping the water temperature almost the same as the indoor temperature. I'll be able to sleep better tonight and not feel the need to go out turn on each faucet every few hours.

[Gene]

Did you run the water long enough to clear the line and actually get to the water from the bottom of the tank? Did you take into account that friction in the lines and the water pump will increase the water temp slightly?

The 2nd point probably makes no difference.

Gene