Camper Conversion Fan/Ventilation... Necessity or Luxury?

[fionnwilliam]

Looking at various 12v fan installs and am beginning to feel unsure about the necessity of fan ventilation...

Van usage sees us away for two or three nights at a time, using gas stove with potential to cook outside undercover of awning if needs be. Sliding bonded window on near side allows fresh air to circulate but the further I get into the conversion and the more im considering a roof fan to avoid excess future damp/condensation. Despite this, I'm not a fan (pun time) of the effect it would have on our T6's outline, so keen to hear if you can manage living comfortably without savaging a hole and sticking one on the roof.

Found this fan that seems to do a better job of maintaining a low profile but am all ears for other suggestions..
Thanks in advance

Black 12v Low Profile Motorised Turbo Roof Air Vent & Extractor Fan - H Bowers

Black 12v Low Profile Motorised Turbo Roof Air Vent & Extractor Fan from H Bowers who specialise in the sale of automotive components.

www.bowerspartsonline.co.uk

 

[Bigsidavies]

The thing is that ventilation and a warm van are a compromise. So you’ll lose all your heat if you have an extractor on the roof.
Also, when it’s cold and damp leaving a window open can be letting in cold wet air in exchange for your warm damp air.
We find that it makes very little difference if we leave the slider open slightly and/or the front windows down an inch. We still get plenty of condensation.
If we put our external thermal blind on the screen and front windows then they get no condensation at all, even with all windows shut.
Other windows get condensation, but it seems localised to the window (ie the carpet around the sides and bottom of the windows is not damp) and in the morning we open the blinds and wipe the windows with a cloth.
Obviously it’s only a problem in colder months.
Personally I wouldn’t want a fan on my roof and the compromise is easily dealt with.

 

[fionnwilliam]

The thing is that ventilation and a warm van are a compromise. So you’ll lose all your heat if you have an extractor on the roof.
Also, when it’s cold and damp leaving a window open can be letting in cold wet air in exchange for your warm damp air.
We find that it makes very little difference if we leave the slider open slightly and/or the front windows down an inch. We still get plenty of condensation.
If we put our external thermal blind on the screen and front windows then they get no condensation at all, even with all windows shut.
Other windows get condensation, but it seems localised to the window (ie the carpet around the sides and bottom of the windows is not damp) and in the morning we open the blinds and wipe the windows with a cloth.
Obviously it’s only a problem in colder months.
Personally I wouldn’t want a fan on my roof and the compromise is easily dealt with.

Thats the sort of feedback I was looking for. Thanks!
Have been looking at the Rainbow thermal blinds recently. Do they cut it?

 

[Bigsidavies]

Thats the sort of feedback I was looking for. Thanks!
Have been looking at the Rainbow thermal blinds recently. Do they cut it?

I believe they are premium (price reflects this).
I’m using the ones from JustKampers. They’ve been great. Fit fine. Go on quickly and a quick shake gets most rainwater off. I’ve got the knack now of folding them up on the bonnet so they fit straight back in the cupboard without getting all the crap on them from a field or wherever.

Just Kampers External Thermoscreen (Silver) VW T5 2003–2015 VW T6 2015 on

Please note: These are shower proof but NOT waterproof. They will need to dry out before packing away

www.justkampers.com

 

[TrevorK]

I believe they are premium (price reflects this).
I’m using the ones from JustKampers. They’ve been great. Fit fine. Go on quickly and a quick shake gets most rainwater off. I’ve got the knack now of folding them up on the bonnet so they fit straight back in the cupboard without getting all the crap on them from a field or wherever.

Just Kampers External Thermoscreen (Silver) VW T5 2003–2015 VW T6 2015 on

Please note: These are shower proof but NOT waterproof. They will need to dry out before packing away

www.justkampers.com

Another vote for JustKampers screen.
I was reluctant to cut a hole in the roof and made an extractor fitted in my sliding window.
Very little condensation now.
Fan heater rally helps if you are on hook-up.

 

[CAB]

Wind deflectors (Heko or Climair) allow cracking open the front windows.

 

[Stuka]

Another vote for JustKampers screen.
I was reluctant to cut a hole in the roof and made an extractor fitted in my sliding window.
Very little condensation now.
Fan heater rally helps if you are on hook-up.

I am looking for some sort of forced air van cooling on site. What was the extractor you fitted to the sliding window and how did you fit it.

 

[TrevorK]

I tried to find something suitable a few years back.
Apparently everything out there is designed for VW factory windows only, so I made something similar with 4mm ply and bits and bobs off of eBay.
The top and bottom slides secure it in the glass channel, held tight by wing nuts. When camping I leave it in place all the time.

Gelid Silent 12 120mm Quiet Case Fan 4897025780118 | eBay

For full item description.

www.ebay.co.uk

I bought this fan as I wanted to leave it on overnight although it’s on 24/7 at the moment.
There are various speeds available, the higher the speed the greater the volume (dB and cfm!).
Runs on a 12v plug, though USB versions available.
Combined with a small fan heater it does enough to avoid condensation.

 

[Stuka]

Thanks for the reply Trevor. I will look into making something similar. Thanks

 

[TWB-Mark]

I've been looking into this too.
I think this product may be a good option:

https://www.amazon.co.uk/dp/B09CRB7Z3P/?coliid=I2BCJD00DA29K2&colid=2Q8OD6ITQ28JY&psc=1&ref_=lv_ov_lig_dp_it

It's a self-contained solar powered roof extractor fan. Doesn't cost the earth and wont drain the battery or need wiring in.
My logic: Will only be powered up in the daytime when there is sufficient sun so will do a good job of cooling the van on a hot day. On a cold day there wont be much sun and I can always put a small cap over the inner end or cover the solar panel with tape in winter if I want to force it off.
Just wondering if anyone's installed one of these in a pop top before and has any feedback?
Personally from having had a T2s, Rapido motorhome, self-builds 3.5 Movano before becoming a very happy owner of a T6 with pop top, I've found that dew point condensation is always a real issue. When I first got my panel van to do a self-build and it was completely empty every morning there were puddles of water on the floor and this was in summer! I installed one of those wind-blown spinning fans on the roof and the condensation puddles disappeared. In winter when I had the heating on I'd block it off, but in the day I'd open it. What I've found is that whenever there's a cold surface (windscreen) and humidity (breath/cooking) there's going to be condensation. For example even on a hot day if you take a cold beer out the fridge and pop it on the table you'll see condensation on the bottle.

 

[Tekniques]

I have a SWB 6.1 and am planning out my build. Looking at the Max Air Fans, popular with the Sprinters in the US and generally larger vans, they just seem too big and I don't want to cut a 300 or 400mm hole in a SWB van. Watching all the YouTube videos it seems most of you with pop tops don't have a fan on the roof due to the pop top and likely don't need one when its up anyway. But what is everyone else doing that don't have pop tops for roof ventilation? I only plan on using it as a weekender, 2 nights sleeping and no cooking inside etc...

 

[DXX]

Keep it simple, slightly open cab windows and if necessary a tail gate bar does the job. Spend the money on fully insulating and avoid a black or dark coloured van