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Why do spinning van roof vents work better?
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? |
Why do spinning van roof vents work better?
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. |
Why do spinning van roof vents work better?
On 25/10/2018 15:47, 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? As it spins I think it disperses driver/passenger farts far more efficiently. |
Why do spinning van roof vents work better?
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? How can you take power from the wind to then give it back to make it faster? Isn't that breaking the laws of physics? |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:06:10 +0100, Andy Bennet wrote:
On 25/10/2018 15:47, 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? As it spins I think it disperses driver/passenger farts far more efficiently. Is there a special catalyst inside it for that? |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... 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? you should worry about something important...tee hee |
Why do spinning van roof vents work better?
Gym Sulkinson Fork wrote
Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... 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. 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. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:18:54 +0100, Jim GM4DHJ ... wrote:
"Gym Sulkinson Fork" wrote in message ... 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? you should worry about something important...tee hee Like? I wasn't doing anything else at the time, I was waiting for someone to answer their door. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:20:54 +0100, Ralph Mowery wrote:
In article , says... 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 powered by the wind that is blowing, not wind they are making. Why not just channel the blowing wind where you want it instead of converting energy twice? In the case of the van, they are powered by the wind pressure the van creates when moving. The above link claims it works when stationary too (by wind). |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:25:20 +0100, Rod Speed wrote:
Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. But the point is to move air into or out of (shouldn't matter which, air still goes through the van) where the vent is. Why not just let the wind blow the air into the van? Making that wind turn a vent which then sucks air in is utterly pointless. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:31:38 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... 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. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:20:54 +0100, Ralph Mowery wrote: In article , says... 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 powered by the wind that is blowing, not wind they are making. Why not just channel the blowing wind where you want it instead of converting energy twice? Because those things are extracting air from the house or van so that isnt possible. In the case of the van, they are powered by the wind pressure the van creates when moving. The above link claims it works when stationary too (by wind). Yes it does. You've likely noticed that houses don't actually move very fast and do have those vents too. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:25:20 +0100, Rod Speed wrote: Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. But the point is to move air into or out of (shouldn't matter which, air still goes through the van) where the vent is. It does actually, particularly when getting it to remove the hot air in the roof space in summer. Why not just let the wind blow the air into the van? Doesn't work when the van is stationary. Making that wind turn a vent which then sucks air in is utterly pointless. Wrong. That's the way the hot air in the roof space wants to go, out of the roof space, and so its better to help it go where it wants to go, with a fan and have the fan powered by the wind. Yes, with houses, an electric fan is better, but the big advantage with those wind powered fans is that its driven by the wind. |
Why do spinning van roof vents work better?
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 ... 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, 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. |
Why do spinning van roof vents work better?
On 25/10/2018 16:07, Gym Sulkinson Fork wrote:
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?* How can you take power from the wind to then give it back to make it faster?* Isn't that breaking the laws of physics? They are a Savonius rotor, which uses the wind to rotate a shaft. There is a fan attached to the shaft, which, unlike a simple hole, actively extracts air from the vehicle. They are also widely used on boats, to keep them ventilated while sitting at their moorings. -- -- Colin Bignell |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:04:57 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:20:54 +0100, Ralph Mowery wrote: In article , says... 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 powered by the wind that is blowing, not wind they are making. Why not just channel the blowing wind where you want it instead of converting energy twice? Because those things are extracting air from the house or van so that isnt possible. Why is it better to move it out instead of in? It still has to go in somewhere and out somewhere else. Same ventilation takes place overall. In the case of the van, they are powered by the wind pressure the van creates when moving. The above link claims it works when stationary too (by wind). Yes it does. You've likely noticed that houses don't actually move very fast and do have those vents too. I've occasionally seen them on old houses on chimneys. I thought that was to disperse the smoke. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:09:56 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:25:20 +0100, Rod Speed wrote: Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. But the point is to move air into or out of (shouldn't matter which, air still goes through the van) where the vent is. It does actually, particularly when getting it to remove the hot air in the roof space in summer. but if you let the wind blow it in, then it goes out where it's currently coming in. Why not just let the wind blow the air into the van? Doesn't work when the van is stationary. The same wind that currently spins the vent could do so. |
Why do spinning van roof vents work better?
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 ... 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. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:11:41 +0100, Nightjar wrote:
On 25/10/2018 16:07, Gym Sulkinson Fork wrote: 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? How can you take power from the wind to then give it back to make it faster? Isn't that breaking the laws of physics? They are a Savonius rotor, which uses the wind to rotate a shaft. There is a fan attached to the shaft, which, unlike a simple hole, actively extracts air from the vehicle. They are also widely used on boats, to keep them ventilated while sitting at their moorings. I'd just open the window (with a rain guard of course). |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:31:38 +0100, Rod Speed wrote: "Gym Sulkinson Fork" wrote in message ... 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. Yes, but that still does help move the hot air out of the roof space. What we have here is something that converts it and then straight back, pointless. What you actually have is a more efficient way of using the wind to power the fan, without the inefficiency involved in the use of electricity between the generator and the fan. You might aswell put a wind turbine and an electric fan connected together on there, Yes, that would certainly work too. it would be no more stupid. Much more stupid given how inefficient the wind powered generator is. Much better to have the wind turn the vent and have the fan part of that thing that turns, directly coupled. 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, Yes. which was already there anyway. Nope, not with the hot air in the roofspace. It would be like having a solar powered lightbulb. Nope, those are much less efficient and we do have solar powered light bulbs, with batterys in them so you get the light at night after the sun is gone. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:04:57 +0100, Rod Speed wrote: "Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:20:54 +0100, Ralph Mowery wrote: In article , says... 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 powered by the wind that is blowing, not wind they are making. Why not just channel the blowing wind where you want it instead of converting energy twice? Because those things are extracting air from the house or van so that isnt possible. Why is it better to move it out instead of in? Because the hot air in the roofspace is already trying to get out and it works better to help it do what its trying to do than to try to stop it doing what it is already trying to do. It still has to go in somewhere and out somewhere else. Yes, but its better to help it move faster in the direction it already wants to go. Same ventilation takes place overall. Nope, you move more hot air when you help it to go in the direction it already wants to go, with a fan. In the case of the van, they are powered by the wind pressure the van creates when moving. The above link claims it works when stationary too (by wind). Yes it does. You've likely noticed that houses don't actually move very fast and do have those vents too. I've occasionally seen them on old houses on chimneys. I thought that was to disperse the smoke. Nope, its just another example of a wind powered fan which helps the air in the chimney move the way it wants to go. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:09:56 +0100, Rod Speed wrote: "Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:25:20 +0100, Rod Speed wrote: Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. But the point is to move air into or out of (shouldn't matter which, air still goes through the van) where the vent is. It does actually, particularly when getting it to remove the hot air in the roof space in summer. but if you let the wind blow it in, then it goes out where it's currently coming in. Yes, but is going against the natural flow of the hot air coming out of the roofspace, so doesn't work as well. Think of electrically powered exhaust fans. The work much getter moving the air out of the roofspace than moving outside air into the the roofspace. Makes no difference how that fan is powered, still works better to move the hot air in the roofspace in the way it wants to go by convection. Why not just let the wind blow the air into the van? Doesn't work when the van is stationary. The same wind that currently spins the vent could do so. But with a van, it also works when there is no wind and the van is moving. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... 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 ... 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. |
Why do spinning van roof vents work better?
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:11:41 +0100, Nightjar wrote: On 25/10/2018 16:07, Gym Sulkinson Fork wrote: 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? How can you take power from the wind to then give it back to make it faster? Isn't that breaking the laws of physics? They are a Savonius rotor, which uses the wind to rotate a shaft. There is a fan attached to the shaft, which, unlike a simple hole, actively extracts air from the vehicle. They are also widely used on boats, to keep them ventilated while sitting at their moorings. I'd just open the window (with a rain guard of course). Doesn't work when the boat is unattended and those things are completely automatic, you don't need to know when it might rain and when to shut the window. |
Why do spinning van roof vents work better?
Hang on though, to make it spin it has to have drag. If it has drag its
using fuel. Might be moor efficient then to streamline the van and run the fan from the van electrics which is there already. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Rod Speed" wrote in message ... Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. |
CAUTION!!! Birdbrain, the Abnormal Pathological Attention Whore, Strikes, AGAIN!
On Thu, 25 Oct 2018 15:47:48 +0100, Birdbrain Macaw (now "James Wilkinson"),
the pathological resident idiot and attention whore of all the uk ngs, blathered again: FLUSH the abnormal attention whore's latest idiotic attention-baiting bull**** unread again -- about Birdbrain Macaw's (now "James Wilkinson" LOL) trolling: "He is a well known attention seeking troll and every reply you make feeds him. Starts many threads most of which die quick as on the UK groups anyone with sense Kill filed him ages ago which is why he now cross posts to the US groups for a new audience. This thread was unusual in that it derived and continued without him to a large extent and his silly questioning is an attempt to get noticed again." MID: -- ItsJoanNotJoann addressing Birdbrain Macaw's (now "James Wilkinson" LOL): "You're an annoying troll and I'm done with you and your stupidity." MID: -- AndyW addressing Birdbrain: "Troll or idiot?... You have been presented with a viewpoint with information, reasoning, historical cases, citations and references to back it up and wilfully ignore all going back to your idea which has no supporting information." MID: -- Phil Lee adressing Birdbrain Macaw: "You are too stupid to be wasting oxygen." MID: -- Phil Lee describing Birdbrain Macaw: "I've never seen such misplaced pride in being a ****ing moronic motorist." MID: -- Tony944 addressing Birdbrain Macaw: "I seen and heard many people but you are on top of list being first class ass hole jerk. ...You fit under unconditional Idiot and should be put in mental institution. MID: -- Pelican to Birdbrain Macaw: "Ok. I'm persuaded . You are an idiot." MID: -- DerbyDad03 addressing Birdbrain Macaw (now "James Wilkinson" LOL): "Frigging Idiot. Get the hell out of my thread." MID: -- Kerr Mudd-John about Birdbrain Macaw (now "James Wilkinson" LOL): "It's like arguing with a demented frog." MID: -- Mr Pounder Esquire about Birdbrain Macaw (now "James Wilkinson" LOL): "the **** poor delivery boy with no hot running water, 11 cats and several parrots living in his hovel." MID: -- Rob Morley about Birdbrain: "He's a perennial idiot" MID: 20170519215057.56a1f1d4@Mars -- JoeyDee to Birdbrain "I apologize for thinking you were a jerk. You're just someone with an IQ lower than your age, and I accept that as a reason for your comments." MID: l-september.org -- Sam Plusnet about Birdbrain (now "James Wilkinson Sword" LOL): "He's just desperate to be noticed. Any attention will do, no matter how negative it may be." MID: -- asking Birdbrain: "What, were you dropped on your head as a child?" MID: -- Christie addressing endlessly driveling Birdbrain Macaw (now "James Wilkinson" LOL): "What are you resurrecting that old post of mine for? It's from last month some time. You're like a dog who's just dug up an old bone they hid in the garden until they were ready to have another go at it." MID: -- Mr Pounder's fitting description of Birdbrain Macaw: "You are a well known fool, a tosser, a pillock, a stupid unemployable sponging failure who will always live alone and will die alone. You will not be missed." MID: -- Richard to pathetic ****** Hucker: "You haven't bred? Only useful thing you've done in your pathetic existence." MID: -- about Birdbrain (now "James Wilkinson" LOL): ""not the sharpest knife in the drawer"'s parents sure made a serious mistake having him born alive -- A total waste of oxygen, food, space, and bandwidth." MID: -- Mr Pounder exposing sociopathic Birdbrain: "You will always be a lonely sociopath living in a ******** with no hot running water with loads of stinking cats and a few parrots." MID: -- francis about Birdbrain (now "James Wilkinson" LOL): "He seems to have a reputation as someone of limited intelligence" MID: -- Peter Moylan about Birdbrain (now "James Wilkinson" LOL): "If people like JWS didn't exist, we would have to find some other way to explain the concept of "invincible ignorance"." MID: |
Senile Ozzie Troll Alert!
On Fri, 26 Oct 2018 02:31:38 +1100, cantankerous trolling senile geezer Rot
Speed blabbered, again: That isnt how they work. Think of it as a fan, We think of you and him as the two village idiots on these groups! -- Archibald Tarquin Blenkinsopp addressing Rot Speed: "You really are a clueless pillock." MID: |
Troll-feeding Senile IDIOT Alert!
|
Troll-feeding Senile IDIOT Alert!
On Thu, 25 Oct 2018 16:06:10 +0100, Andy Bennet, another troll-feeding
senile idiot, blathered: As it spins I think it disperses driver/passenger farts far more efficiently. ....and troll-feeding senile idiot no.2 appeared to do the Scottish ****** and attention whore the favour he is after! tsk |
Troll-feeding Senile IDIOT Alert!
On Thu, 25 Oct 2018 11:20:54 -0400, Ralph Mowery, another obviously mentally
handicapped troll-feeding senile idiot, blathered: They are powered by the wind that is blowing, not wind they are making. In the case of the van, they are powered by the wind pressure the van creates when moving. The Scottish sow, ******, troll and attention whore thanks you nicely for taking his latest idiotic bait, troll-feeding senile idiot no.3! BG |
Senile Ozzie Troll Alert!
On Fri, 26 Oct 2018 02:25:20 +1100, cantankerous trolling senile geezer Rot
Speed blabbered, again: FLUSH troll **** Let me get this straight: it's 02:25 am in Australia and you are up and trolling AGAIN? Just how many hours do you sleep every night? Is it your senile hormones that won't let you sleep? Or is it your loneliness? Or you medication? And why does obviously NO ONE in real life want to talk to you? BG -- FredXX to Rot Speed: "You are still an idiot and an embarrassment to your country. No wonder we shippe the likes of you out of the British Isles. Perhaps stupidity and criminality is inherited after all?" Message-ID: |
Why do spinning van roof vents work better?
On 10/25/2018 12:15 PM, Gym Sulkinson Fork wrote:
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 ... 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. If not trolling, just a hardhead that refuses to accept a better idea that works. Have you tried one? |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 16:07:30 +0100, "Gym Sulkinson Fork"
wrote: 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? How can you take power from the wind to then give it back to make it faster? Isn't that breaking the laws of physics? Any ambient wind will spin the turbine and pump air out. On a perfectly calm day, I doubt there is much gain at all. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:27:20 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:04:57 +0100, Rod Speed wrote: "Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:20:54 +0100, Ralph Mowery wrote: In article , says... 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 powered by the wind that is blowing, not wind they are making. Why not just channel the blowing wind where you want it instead of converting energy twice? Because those things are extracting air from the house or van so that isnt possible. Why is it better to move it out instead of in? Because the hot air in the roofspace is already trying to get out and it works better to help it do what its trying to do than to try to stop it doing what it is already trying to do. It still has to go in somewhere and out somewhere else. Yes, but its better to help it move faster in the direction it already wants to go. Same ventilation takes place overall. Nope, you move more hot air when you help it to go in the direction it already wants to go, with a fan. Ok, I accept your explanation. What surprises me though is just how much hot air rises. Is there a formula to determine for example, in a container of certain dimensions, how much hotter the top will be than the bottom? In the case of the van, they are powered by the wind pressure the van creates when moving. The above link claims it works when stationary too (by wind). Yes it does. You've likely noticed that houses don't actually move very fast and do have those vents too. I've occasionally seen them on old houses on chimneys. I thought that was to disperse the smoke. Nope, its just another example of a wind powered fan which helps the air in the chimney move the way it wants to go. I rarely see them here, on any type of boiler/fireplace arrangement. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:31:23 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:09:56 +0100, Rod Speed wrote: "Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 16:25:20 +0100, Rod Speed wrote: Gym Sulkinson Fork wrote Why are these fitted instead of just a stationary vent like you see on caravans? They act like a pump. 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. It isnt from the place you want to move it from. Surely that's like fitting a generator to your bicycle to power a motor to make you go faster? Nope, more like using a wind generator to generate electricity and using the electricity to drive a fan, but without the losses involved with the electricity generation and the electrical fan. But the point is to move air into or out of (shouldn't matter which, air still goes through the van) where the vent is. It does actually, particularly when getting it to remove the hot air in the roof space in summer. but if you let the wind blow it in, then it goes out where it's currently coming in. Yes, but is going against the natural flow of the hot air coming out of the roofspace, so doesn't work as well. Think of electrically powered exhaust fans. The work much getter moving the air out of the roofspace than moving outside air into the the roofspace. Makes no difference how that fan is powered, still works better to move the hot air in the roofspace in the way it wants to go by convection. I tend to do that when designing desktop computers, but mainly because of where the hot chips are and what needs the most cooling. I have intake fans front bottom cooling the disks, then across the graphics card, then over the CPU then out the top back and/or top. |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:34:23 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... 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 ... 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. And surely a van just isn't tall enough to have much of a temperature differential by height? |
Why do spinning van roof vents work better?
On Thu, 25 Oct 2018 17:35:48 +0100, Rod Speed wrote:
"Gym Sulkinson Fork" wrote in message ... On Thu, 25 Oct 2018 17:11:41 +0100, Nightjar wrote: On 25/10/2018 16:07, Gym Sulkinson Fork wrote: 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? How can you take power from the wind to then give it back to make it faster? Isn't that breaking the laws of physics? They are a Savonius rotor, which uses the wind to rotate a shaft. There is a fan attached to the shaft, which, unlike a simple hole, actively extracts air from the vehicle. They are also widely used on boats, to keep them ventilated while sitting at their moorings. I'd just open the window (with a rain guard of course). Doesn't work when the boat is unattended and those things are completely automatic, you don't need to know when it might rain and when to shut the window. That's why I said rain guard. I've seen caravans with a roof vent with a hat n top to stop the rain. |
Why do spinning van roof vents work better?
But the power taken from the alternator would surely be just as bad as the wind drag? Both are putting extra strain on the engine. I wonder if anyone has ever studied whether you should (for fuel efficiency) open your car window when driving on a hot day or use the cooling fan (ignoring AC for the moment).
On Thu, 25 Oct 2018 17:43:18 +0100, Brian Gaff wrote: Hang on though, to make it spin it has to have drag. If it has drag its using fuel. Might be moor efficient then to streamline the van and run the fan from the van electrics which is there already. Brian |
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