I thought that as we're not using the van in the winter months and it's parked up at home I'd run the heater for a few hours every month or so during the damp winter season. Might just keep damp and mould at bay.
Anyone run their heater when caravan not in use?
- Thread starter Sam Vimes
- Start date
Never heated the caravan over winter as it was in store or being used. Just ensured good ventilation and opened everything up, and put furnishings on their sides. Prior to winter all surfaces had a wash down but never used spray polish or the like. Was never affected by mould. But western Scotland could be different given its propensity for wet stuff.
Good ventilation is far more important than heating. I have never heated any leisure vehicle over winter for 20+ years, but I have always ensured good ventilation. Never had any mould etc.
I believe the constant warming up and cooling down creates an environment conducive to mould growth. I too have never heated the caravan in winter storage, only when we use it.
As you may remember condensation usually occurs when warm air takes up moisture then as it cools it cant hold as much moisture so it deposits it as rain or as condensation on cooler surfaces the air touches. Exactly the same applies to the wooden structure of the caravan, as you warm wood it can absorb more moisture than which it has to try and get rid of when it cools down again. That moisture in the wooden and other absorbent materials is held on the surface which is one of the causes for mould to grow.
Basically adding heat can cause the caravan to absorb even more moisture which means when you turn the heater off it provides even more surface moisture which mould loves.
Incidentally the same thing can happen if a caravan is stored where sunshine can heat parts, whilst other parts in the shadows are still cool and that is another mechanism that can promote mould growth.
Ventilation is the simplest and cheapest method of helping to prevent condensation, and mould. A good wie round with an anti mould solution is also helpful to remove as many dormant spoor's as possible.
Basically adding heat can cause the caravan to absorb even more moisture which means when you turn the heater off it provides even more surface moisture which mould loves.
Incidentally the same thing can happen if a caravan is stored where sunshine can heat parts, whilst other parts in the shadows are still cool and that is another mechanism that can promote mould growth.
Ventilation is the simplest and cheapest method of helping to prevent condensation, and mould. A good wie round with an anti mould solution is also helpful to remove as many dormant spoor's as possible.
Yes we did back when we caravanned all through the year, saved having to drain down completely to avoid frost damage.
Most times I used a thermostat switched electric fan heater as the Alde's minimum of 5 degrees is a bit higher than needed, but have used that on those occasions when it was the more expedient method.
When van properly drained there is little point, other than I tend to like to periodically use systems like this, rather than leave unused for months.
The higher cost of energy today might make a difference, if we were continuing with our all season caravanning. But in reality a stat set to just above freezing would see little running time here in the southern area.
Most times I used a thermostat switched electric fan heater as the Alde's minimum of 5 degrees is a bit higher than needed, but have used that on those occasions when it was the more expedient method.
When van properly drained there is little point, other than I tend to like to periodically use systems like this, rather than leave unused for months.
The higher cost of energy today might make a difference, if we were continuing with our all season caravanning. But in reality a stat set to just above freezing would see little running time here in the southern area.
What do you do to ensure good ventilation? On my caravan there are two mushroom vents, one above the shower and one above the microwave. I believe that the skylights allow some airflow even when closed, and there is at least one vent in the floor under the bench seat (there might be one each side). I leave all cupboard and locker doors open. Is that enough or should I be doing something else?
I am fortunate insomuch as my caravan is stored alongside my house, so I am able to open the door and roof hatch on fine winter days. I do also leave the (downwind) windows on the ventilation setting permanently.
If it was in storage then I would probably leave a couple of windows cracked open on the ventilation setting.
If it was in storage then I would probably leave a couple of windows cracked open on the ventilation setting.
It also helps to remove all soft furnishings, and open cupboards and bed lockers to allow free flow of air inside.
.....the advice of good ventilation is sound.
Heating the air inside a caravan increases it's ability to remove moisture from the hygroscopic materials present.
The moist air then has to be removed from the caravan to complete the drying effect.
Damp levels vary as to the geographical location of the caravan.
Annual rainfall.....
Isle of Skye = 1770mm
Weymouth = 770mm
Whether it is worth the expense of heating is an individual decision.
Heating the air inside a caravan increases it's ability to remove moisture from the hygroscopic materials present.
The moist air then has to be removed from the caravan to complete the drying effect.
Damp levels vary as to the geographical location of the caravan.
Annual rainfall.....
Isle of Skye = 1770mm
Weymouth = 770mm
Whether it is worth the expense of heating is an individual decision.
Mel
Moderator
We have an electric air conditioner/dehumidifier. Free standing unit. If our van was on our drive ( which it isn’t), I would run that in there a couple of times a month for a few hours.
Mel
Mel
When our caravan was in storage in the winter months it had a breathable cover on but we left all of the windows on the night latch .and all the cupboards and doors left open to allow the air to flow .
Mel
Moderator
I agree that running it constantly is ineffective but on a short stint it would presumably draw out the moisture in the immediate vicinity first, i.e. the caravan, before attempting to dehumidify the rest of the East Midlands, and in doing so would move the air around in the caravan, drawing it through ventilation points and aiding ventilation.
Mel
Given that hot air rises, some of the moisture laden air would leave the caravan through the vents in the roof and cooler dry(er) air would be drawn in through the vents in the floor, so I agree that it would aid ventilation. It would be interesting to know how long a complete air change would take. The same must happen when the sun hits the caravan and increases the inside temperature.
On my caravan there is, by design, an approximately 1cm gap held by spacers between the floor panel and the walls all the way round and of course the roof lights also have provisions to let a certain amount of air through even when shut, so adequate ventilation is assured even if the windows are fully shut.
Some UK made caravans can create their own gap between the floor and walls. How cool is that?
I use a small(ish) electric dehumidifier as the van is parked at the side of the house. I have heard many times the argument that I am "trying to dry up the world"
I block most of the vents while it is on and after a couple of days the tank is full then it takes progressively longer to fill until it does not remove any more moisture at all. This I repeat a couple of times over the winter and I have never had any damp or mould at all so it either works or I have just been fortunate!
Either way I do know that it is 3 to5 l of water each time that is not in the van and I happen to have the dehumidifier anyway so why not?
I block most of the vents while it is on and after a couple of days the tank is full then it takes progressively longer to fill until it does not remove any more moisture at all. This I repeat a couple of times over the winter and I have never had any damp or mould at all so it either works or I have just been fortunate!
Either way I do know that it is 3 to5 l of water each time that is not in the van and I happen to have the dehumidifier anyway so why not?
That may work but you MUST ensure all the vents are unblocked before using the caravan.
As soon as you use the caravan the humidity levels will begin to reset to ambient conditions. It questionable whether use of a dehumidifier whilst in storage has any real benefit - It won't do any harm except to your wallet.
Mel
Moderator
OK clearly I am using faulty logic here; so here are my “workings out”. Which step is sending me in the wrong direction.
1. Using a dehumidifier immediately after using the van will remove the moisture generated by use ( breathing, showering etc). Thus the van now contains less moisture than before I used the dehumidifier.
2. When the van is not used, over time the moisture inside increases due to airborne ambient moisture.
3. Even with some ventilation the moisture will increase over time as it is trapped in the van so that it rises above external ambient.
4. Deployment of a dehumidifier for a fixed period will reduce the moisture content to below external ambient especially in a small 2 berth such as we have as the dehumidifier will remove moisture faster than it is getting in.
Steps2, 3 and 4 repeat over storage time.
Outcome: the moisture content of the van is managed to be at or below ambient for considerable portions of storage time.
Couple of caveats; our van is not on the driveway so cannot try this- it is a thought experiment ( Shrodinger’s dehumidifier 😀)
Also not read any peer reviewed papers that experimentally demonstrate results.
Thoughts?
Mel
I can see your logic but I question what it is actually achieving as you dont measure humidity and moisture content over time and compare with ambient. When I shut down our caravans I never attempted to heat or dehumidify them. Just opened all doors and lockers and turned the furnishings on their edges. I never experienced any mould during those periods. Before setting off on our New Years and later winter breaks I didn’t even pre heat the van when I bought it back from storage. Once on site the heating was turned up and it quickly became comfortable. If you are not getting mould why waste electricity and cash? If you are getting mould then something is wrong.
This is essentially correct, becasue when the caravans internal moisture levels are above the ambient air levels, the caravan will be ready to redress that imbalance by releasing its excess levels to the circulating air. The air is carried outside, and the replace by fresher air at a lower level of humidity. This will will continue until the internal and external levels are equalised. Using a dehumidifier accelerates this process, which is why it may make sense to use one for a few days at the beginning of storage.
This is not accurate. Assuming the caravan is ventilated, the moisture levels inside a stored caravan will track the moisture levels in the ambient outside air, they can go both up and down becasue the air is continually exchanging with external air.
No. See the comment above.
This is uncertain and should not be assumed to be true, it would depend on the dehumidifier, size of the caravan and the relative levels of humidity in the atmosphere, because a caravan with unimpeded statutory ventilation would be able to exchange quite a lot external air to offset the moisture removed by the dehumidifier.
A caravan put into storage will naturally over time settle to match the ambient levels of moisture - with appropriate ventilation.
Attempting to remove moisture by using a dehumidifier is only removing the moisture from the air around it, but if that air is constantly being replaced with external air through the fixed ventilation you are effectively only removing th e moisture from the air entering and leaving the caravan. The effect on the materials in the caravan will be minimal if any.
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