On Thu, 25 Oct 2018 21:13:42 +0100, Rod Speed wrote:



"Gym Sulkinson Fork" wrote in message
news
On Thu, 25 Oct 2018 17:34:23 +0100, Rod Speed
wrote:



"Gym Sulkinson Fork" wrote in message
news On Thu, 25 Oct 2018 17:10:21 +0100, Pat wrote:

On Thu, 25 Oct 2018 16:58:21 +0100, "Gym Sulkinson Fork"
wrote:

On Thu, 25 Oct 2018 16:31:38 +0100, Rod Speed

wrote:



"Gym Sulkinson Fork" wrote in message
news On Thu, 25 Oct 2018 16:03:22 +0100, wrote:

On Thu, 25 Oct 2018 15:47:48 +0100, "Gym Sulkinson Fork"
wrote:

Why are these fitted instead of just a stationary vent like you
see
on
caravans?

http://www.flettner.co.uk/van-roof-vents/

I don't see the point in using the wind to power a vent, when the
air
was already moving. Surely that's like fitting a generator to
your
bicycle to power a motor to make you go faster?

They are just more efficient than a simple hole in the roof with
sufficient cover to keep the rain out. If there was a better mouse
trap, somebody would have made one in the last 200 years.

Yes I know they claim to be more efficient, but why?

Because they are a fan, powered by the wind.

A turbine converts wind to electricity. A fan converts electricity to
wind. What we have here is something that converts it and then
straight
back, pointless. You might aswell put a wind turbine and an electric
fan connected together on there, it would be no more stupid.

How can you take power from the wind to then give it back to make it
faster?

That isnt how they work. Think of it as a fan,
which even you should realise is better than
no fan, and powering that fan with the wind.

Isn't that breaking the laws of physics?

Nope.

But you're powering that "fan" by the motion of the air, then using
the
power to create motion of air, which was already there anyway. It
would
be like having a solar powered lightbulb.

I suspect you are just trolling,

I'm not.

but I'll chime in anyway. These
devices use the motion of the air traveling past your building (ie,
horizontal motion) into suction that draws hot air up and out of your
building. They work better than just using the upward motion of the
air created by hot air being lighter than cooler air.

I find it hard to believe it really matters whether the air goes in our
out.

Think of an electrically power exhaust fan.

Surely even you can understand that one that is mounted horizontally
at the peak of the roof will work better moving the hot air out of the
roofspace than moving external air into the roofspace.

That's what those things are, but wind powered instead of electrically
powered.

I would have believed it might make it more comfortable if you're sat
lower down in a building, but once it's been running for a while, the hot
air should still have escaped, no matter where it's going.

There is still more being heated by the less than ideal
insulation of the walls and roof and windows of the van.

And the furious wanking of the occupant in your case too.

It amuses me that you think of me in that way. Do you dream about me every night?