sky light open?

[rooster63]

Was wondering about the wisdom of driving with the sky light open on a campervan. The type that hinge at the front with various opening widths. Realise it might effect mpg but with a TV aerial and awning not sure how much difference that would make. Is there any likelihood that the skylight could be damaged by the slipstream? Does it help make the van any cooler when driving? No air-con in the van and had a very hot journey home today!

[peterjl]

Hi

 

There are two issues.

 

Firstly likelyhood of damage. You are going to put a lot of strain on the arms and winding gear. This will be exacerbated by any crosswinds, eg from large lorries or in areas prone to wind.

 

I have done it by accident and my winding gear jammed. It took some fiddling to unjam so I would not.

 

The second issue is noise. I noticed I had driven off with it open because of the noise. Motorhome are often noisy anyway so why add.

 

Peter

[tonyishuk]

Try a search on "rotating vehicle ventilation ".

 

Some are fairly basic, but some are adjusable and have a maritime look

 

Rgds

[Derek Uzzell]

rooster63 - 2018-05-28 4:00 PM

 

Was wondering about the wisdom of driving with the sky light open on a campervan...

 

Most (all?) motorhome owner manuals will state that roof-lights be fully shut when the motorhome is being driven. For example AutoTrail’s current manual advises in the “Before you set off in your motorhome” section that the motorhome’s owner should “Close and secure all roof lights”.

 

Motorhome design pays little attention to aerodynamics and there’s no guarantee what air-flow over the roof will do. Air-flow over a roof-light might produce a downwards or upwards force but, either way, there’s likely to some loading on an open roof-light. A sturdy roof-light (say a Heki Mini that can be firmly locked in a partially open position might be ‘safe’) but there’d be a much higher risk driving with an open Omni-Vent.

 

This 2007 MHFacts thread discussed driving with roof-lights/windows open

 

http://forums.motorhomefacts.com/21-newcomers/29397-driving-windows-skylights-open.html

 

but there are also plenty of reports of motorhome/caravan roof-lights spontaneously opening during travel despite having being closed beforehand.

 

Personally, I think driving with a roof-light open is just asking for trouble and that the potential negative results of doing so - wind damage to the roof-light, noise, forgetting that a raised roof-light increases the motorhome’s height and hitting it on (say) a tree branch - are plain.

 

If you want more air in the cab, you might consider fitting wind deflectors as discussed here

 

http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Ducato-Spoilers/45871/

[Brock]

Tonyishuk and Derek suggest viable solutions. The devices mentioned by tonyishuk are in common use where ventilation is required in the rear of vans. We have wind deflectors on my wife's car which has no air conditioning. Some motorhomers who go to hot countries fit dashboard fans. These will all improve air flow but I'm not convinced they will cool the air unless the outside air is cooler. We have cotton towels over the seats which help keep us cool, we open cab windows, we wear clothes designed for hot temperatures; we rarely use the cab air conditioning.

 

If you leave your roof light open, there is a risk your roof light will be ripped off. From that, there is a risk that the roof light will hit a pedestrian or more likely a vehicle. You may then be prosecuted and your insurance may be invalid because you did not secure the vehicle. There is a risk the Traffic Police will pull you over and decide to do a thorough check of your van, at best delaying your journey. Risks rarely happen in isolation!

 

I'm sure I must have driven with the roof vent open by mistake and come to no harm. I've seen reports over the year where roof lights have been ripped off with no damage to anyone/anything else and only minor damage to the motorhome.

 

My view is that the probability of the roof light being ripped off increases depending on the quality of build, speed/air flow, and frequency of leaving it open. The likelihood of flying roof light causing damage or injury is also low; but the consequences are very high. Better to suffer or pursue an alternative.

 

 

[malc d]

When touring we have a check list to ensure that everything is secure before we move off from each site - but on one occasion we stopped off at a friends, on the way home, and they were given a ' tour ' of the van.

 

We left them quite late in the evening - long after dark - and ( with the idea that we hadn't used anything ) drove off without the checks and travelled around the M25 for over half an hour with the large roof light fully open.

Although we were travelling at about 60 mph for most of that time, fortunately, no damage was done.

 

It was investigating increased traffic noise that drew our attention to my mistake.

 

My advice would be - if you don't know the possible effects of leaving it open - don't.

 

Why take the chance.

 

;-)

[Tall_Mike]

My recommendation is - don't do it, unless you have a skylight or vent specially designed for this purpose.

 

We inadvertently left our back skylight ajar, wasn't fully wound shut to allow just a little air in, - set off and drove down the motorway, no problem to a point - and didn't notice anything however once reaching a certain speed there was the most horrendous banging from it, guess it's all down to airflow and lift. - slowed down and it settled, - very lucky not to break the thing off - it did strain the joints and connections although fortunately nothing snapped, it was that severe.

 

Take great care now with our 3 skylights to ensure that they are fully closed and locked shut before going anywhere, guess it's a mistake you make once and once only.

[rooster63]

Thanks for all your replies, I had erred on the side of keeping it shut but had seen a number of vehicles with the roof light open so wondered if it was the done thing, obviously not.

[tonyg3nwl]

Hi, a number of years ago, we were following a car caravan combination, when the top roof vent on the caravan departed company from its van, and we managed to avoid it, then overtook the combination, flagged him down and advised him of the near miss,

 

moral, batten down the hatches at all times, or risk a major catastrophy.

 

tonyg3nwl

 

[StuartO]

tonyg3nwl - 2018-06-01 12:42 PMHi, a number of years ago, we were following a car caravan combination, when the top roof vent on the caravan departed company from its van, and we managed to avoid it, then overtook the combination, flagged him down and advised him of the near miss,moral, batten down the hatches at all times, or risk a major catastrophy.tonyg3nwl

We passed a caravan recently which had one of these new, large front-end skylights improperly secured.  It was lifting and falling (with changes of speed) as it was being towed along.  I made a hand signal as we passed (best I could do in the traffic) and I hope he got the message because it seemed unlikely that the skylight would survive for much longer. Some low profile motorhomes have similar large front skylights but I can't imagine one of those lifting without it being very obvious to driver and other occupants!

I have occassionally left out rear 400mm X 400mm, front-hinged skylight unlatched and it might therefore also have flapped up and down unobserved but routinely we either close it or have it in the part open but latched position, providing a mere crack of extraction, which seems to be stable. I doubt that any skylight which is not latched and relies entirely on friction hinges for position would be stable on the move.