Our Puck L windows are on vent setting, under a cover which was designed for a Familia. Lots of circulating air.

So am I to understand that if using a dehumidifier I should seal the van, or would this create other problems?

Alan

No. I just happen to have read several threads on this subject on this forum and am interested in finding out more.

Maybe I should get out more often

Alan

OK, I think we're getting a bit bogged down here so it might help to clarify a few points in my thinking.

Recommended humidity levels in a home, and a caravan is essentially a home when one is living in it, is between 30-50%. However, experts (whoever they might be) suggest that for optimal health and safety 45-55% is recommended.

There comes a point of course at which a humidity level that is too high is not only damaging to health but can also result in mold which is definitely hazardous to health.

Now without having a pretty good hydrometer to hand an accurate measurement of humidity isn't really possible although some indications are obvious e.g. constantly wet window surfaces and damp walls (humidity too high), and dry throat/slight headache, mugginess especially in winter when the central heating is running (humidity too low). Some experts actually recommend a relative humidity lower than 40% during the winter months to prevent condensation.

The use of a Humidifier was mentioned a little earlier so OK, what do these things do? Extract moisture from the atmosphere obviously but if they deplete the atmosphere of sufficient moisture (I'm thinking caravan here) then one possible result is that the woodwork in the van starts to dry out below an acceptable amount and begins to crack. Those who have had the damp test completed by their service workshop will have surely noted from the test report that the crib sheet provides for a minimum and maximum moisture content at various locations in the van.

The green sacks that I referenced to earlier are designed to begin absorbing moisture when the relative humidity reaches 60% or higher and when the air dries out release some of the collected moisture back into the atmosphere again. But, and I know that one shouldn't really start off a sentence with the word but, but who cares lol, the exchanging of the atmosphere e.g. ventilation is also part of the solution and this entails circulation.

It is my contention that whilst a limited amount of air is entering the van from ventilation points dotted around the floor area of the van, with the pop-top down and the covers on there will be very little - if any - circulation of air. I suppose one could also present an argument in saying that by fitting a cover over the van one is essentially providing a double skin because with all the vans windows and door closed tight (seals in excellent condition) there's already a cover on the van. How on earth is air supposed to circulate under these conditions? It would be akin to battening down the hatches at home - a four bedroom detached - and then opening the cat flap for one minute and satisfy oneself that the property has been ventilated.

Low-level background heat, OK, but only if there are not large movements of air i.e. all windows left open on their ventilation settings otherwise one is simply warming the surround atmosphere. The green sacks that I use are effective when the van is locked down tight other than bottom ventilation points of course but the most effective method of keeping damp and the resulting mold at bay is regular ventilation.

Why would you want to ventilate your van after installing the green sacks. It seems to me that all you would achieve is the introduction of more air laden with moisture for the sacks to extract. I say this with very little knowledge or experience, a brief foray on Google informs me that the average humidity in my part of the world (Kent, SE England) is over 70% and you say the green bags are trying to achieve 60%, so it would appear that M Le Pew is right and you would be trying to dehumidify earth. Would you not be better sealing your van rather than ventilating it?

Alan

Quote: Deeps wrote in post #20

---

OK, I think we're getting a bit bogged down here so it might help to clarify a few points in my thinking.

Recommended humidity levels in a home, and a caravan is essentially a home when one is living in it, is between 30-50%. However, experts (whoever they might be) suggest that for optimal health and safety 45-55% is recommended.

There comes a point of course at which a humidity level that is too high is not only damaging to health but can also result in mold which is definitely hazardous to health.

Now without having a pretty good hydrometer to hand an accurate measurement of humidity isn't really possible although some indications are obvious e.g. constantly wet window surfaces and damp walls (humidity too high), and dry throat/slight headache, mugginess especially in winter when the central heating is running (humidity too low). Some experts actually recommend a relative humidity lower than 40% during the winter months to prevent condensation.

The use of a Humidifier was mentioned a little earlier so OK, what do these things do? Extract moisture from the atmosphere obviously but if they deplete the atmosphere of sufficient moisture (I'm thinking caravan here) then one possible result is that the woodwork in the van starts to dry out below an acceptable amount and begins to crack. Those who have had the damp test completed by their service workshop will have surely noted from the test report that the crib sheet provides for a minimum and maximum moisture content at various locations in the van.

The green sacks that I referenced to earlier are designed to begin absorbing moisture when the relative humidity reaches 60% or higher and when the air dries out release some of the collected moisture back into the atmosphere again. But, and I know that one shouldn't really start off a sentence with the word but, but who cares lol, the exchanging of the atmosphere e.g. ventilation is also part of the solution and this entails circulation.

It is my contention that whilst a limited amount of air is entering the van from ventilation points dotted around the floor area of the van, with the pop-top down and the covers on there will be very little - if any - circulation of air. I suppose one could also present an argument in saying that by fitting a cover over the van one is essentially providing a double skin because with all the vans windows and door closed tight (seals in excellent condition) there's already a cover on the van. How on earth is air supposed to circulate under these conditions? It would be akin to battening down the hatches at home - a four bedroom detached - and then opening the cat flap for one minute and satisfy oneself that the property has been ventilated.

Low-level background heat, OK, but only if there are not large movements of air i.e. all windows left open on their ventilation settings otherwise one is simply warming the surround atmosphere. The green sacks that I use are effective when the van is locked down tight other than bottom ventilation points of course but the most effective method of keeping damp and the resulting mold at bay is regular ventilation.

---

I'm reading this thread with avid interest as we have just bought our Eriba and after one shakedown trip this week we're putting it away (on the drive) for the winter. On previous vans we've had (not Eribas) I drained down the water systems but never bothered to do anything other than leave the windows on the vent setting and never had any problems (we live in S. Hampshire if that makes any difference). Main thing I think is to thoroughly inspect every crevice inside to make sure there have been no leaks you haven't noticed since last time - even a small seepage can raise the humidity and cause mould and rot in the vicinity. Our Eriba came with one of these green, 'breathable' covers so I want to try that because the main problem in the past was having to clean all the green gunge off the outside in the spring. I think also on 'nice' days it's worth popping the top too - Mrs Rockin Papy (Scout Leader) says that canvas should never be stored wet and I guess condensation could get in the folds when it's down.

I often wonder why people wait until spring to give their vans a wash. Surely it's not a days job to give it the odd quick wash once or twice before. Or do people not give the car a clean for 4 months of the year LOL.

Went into the van yesterday to bring the cushions and any other fabric/teatowels etc. Found that the cushions were damp from condensation either on the wall or window. Main issue has been some days warm and wet, then sub zero nights followed by lots of sunshine. Perfect for condensation as witnessed in the house.
Part of this is caused by the fact the van is parked East/West with a big hedge on the South side. So, the rear corner gets a lot of sun but the front doesn't. Hence the condensation at the bed end.
Agreed dehumidifier waste of time and unless running at a reasonable temp 24/7 not sure that heating will actually do enough to keep the air dry enough.
So, working on the ventilation side I'm fitting a 4" computer fan which will be running all the time.
Initially I may try putting this below the roof vent, though this would seem to be encouraging more damp air to be sucked up through the floor vents. On the other hand the outside air is going to be drier than trapped warmed air - so, we'll see how it goes. The other option is to put it in the middle pointing the air flow from front to back - just to keep stuff moving.
Not sure about leaving windows in vent position as that will encourage eight legged wildlife of which we have an abundance thanks to the hedge.

Just for fun I thought I'd see what the owners manual has to say on the subject - http://www.325099.co.uk/2012%20Eriba%20Manual.pdf from page 114. Now where did I put the talc?

Quote: Rockin Papy wrote in post #27

---

Just for fun I thought I'd see what the owners manual has to say on the subject......

---