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Thread: Electric Fan without blade

  1. #41
    Deregistered wootsk's Avatar
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    Default Re: Electric Fan without blade

    If you think that the "fan" don't need to clean unlike the blade type, think again. The "fan" works by taking in air from the bottom unit and push out from the gap in the ring. So on the long run, the place where it takes in air will get larger partical stuck and then dust will stick to those partical and you might feel less air flow as time goes by. You might need to place a filter around it and reduce chance of such things happen. But by doing so, you will also has lesser air flow as air needs to pass throught the filter which is a resistance or the machine will have to work harder to get over the restriction. The selling concept of this new product is pratically because it is bladeless and cool looking compared to conventional fan.

    About drying your hair by placing your head close to the middle of the ring, there is no air flow in the middle of the ring. I have 100% convinced that air is taken from the bottom unit and pumped into the gap AROUND THE RING by moving my hand around the test unit in the shop during window shopping.

  2. #42
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    Default Re: Electric Fan without blade

    I found the output not as strong. Its more like a calm breeze. Actually quite expensive, you're paying more for the novelty.

  3. #43
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    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    Those intending to get the dyson fan might want to consider..

    Normally, the demo sets at besk denki, harvey norman etc.. are in an air-conditioned environment. The air is cool.. and when cool air blows on you.. it's feels good..

    But there is an inherent characteristic in the design.. It compresses the air. And, those that are familiar with thermodynamics will be aware that compressing air will heat it up.

    Hence, those close to the strong jet of air in a normal environment might feel warm air. those standing further away will feel less of the effect.

    On a hot day, w/o air-con, using the dyson fan "might" not feel so good..

    probably not a concern for those air-con environment thou.

    A simple experiment.. take a hair dryer, turn off heating. Set max speed and feel it at close range.. does the air feel warm?
    Hair dryer is warm due to heating element!

    The kind of compression for gases to produce heat is huge! The Dyson fan cannot produce that kind of compression. The pressure is even much lesser than a balloon. Balloons don't feel warm do they!?

  4. #44

    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    It's not that the air is warm.. it's warmer than the surrounding air.

    it's a valid point that pple may not need fan in air-con environment.. but the demo are usually in air con environment.. so those shopping for dyson fan, take note..
    Same go to air cooler, the aircon enviroment make it look and feel cool!

  5. #45
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    Default Re: Electric Fan without blade

    Quote Originally Posted by Zplus View Post
    Hair dryer is warm due to heating element!

    The kind of compression for gases to produce heat is huge! The Dyson fan cannot produce that kind of compression. The pressure is even much lesser than a balloon. Balloons don't feel warm do they!?
    Apparently, You didn't read my comments carefully.

    Some hair dryer have the option to turn OFF the heater. For fair comparison, of course we must turn OFF the heater.

    WHY balloon doesn't feel warm.. hmm.. Not sure if I should answer that question..

    ok, just simple facts.. If you fill a balloon from compressed gases cylinder, like helium.. it will feel COOL initially, then reach room temperature.

    If you used a pump to pump in surround air, it will feel warm initially, then reach room temp.

    Those are according to thermodynamic theories.. check out A level text if you're interested.

    Now, I wanna quote something from Primary/Sec school textbook where anyone can follow.

    If you pump a Bicycle tyre, it will feel WARM. It's in Primary/Sec (forgot which one) school science textbooks. After a while, it will reach room temp because of heat lose to surrounding.

  6. #46

    Default Re: Electric Fan without blade

    Just wait for those made in china knock-offs, why must pay few hundreds for a table fan (um...without blades).....
    Fenders American Vintage '62 Stratocaster® Reissue

  7. #47
    Member armadillo's Avatar
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    Default Re: Electric Fan without blade

    will get one if price drop below $200

  8. #48

    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    Apparently, You didn't read my comments carefully.

    Some hair dryer have the option to turn OFF the heater. For fair comparison, of course we must turn OFF the heater.

    WHY balloon doesn't feel warm.. hmm.. Not sure if I should answer that question..

    ok, just simple facts.. If you fill a balloon from compressed gases cylinder, like helium.. it will feel COOL initially, then reach room temperature.

    If you used a pump to pump in surround air, it will feel warm initially, then reach room temp.

    Those are according to thermodynamic theories.. check out A level text if you're interested.

    Now, I wanna quote something from Primary/Sec school textbook where anyone can follow.

    If you pump a Bicycle tyre, it will feel WARM. It's in Primary/Sec (forgot which one) school science textbooks. After a while, it will reach room temp because of heat lose to surrounding.
    Apprantely, my earlier post that there's a "compressor" inside is not true! It turns out that they are only vane. I tried to examine my fan again, I can't seem to see any moving parts!

    Anyway, even if it is compress air, in this case, it'll be insignifant to have any major effect on the temperature.


    Quote Originally Posted by guitarist View Post
    Just wait for those made in china knock-offs, why must pay few hundreds for a table fan (um...without blades).....
    Don't bother, I already got the China knock off..don't waste your money.

  9. #49
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    Default Re: Electric Fan without blade

    Quote Originally Posted by KiichiroToyoda View Post
    Anyway, even if it is compress air, in this case, it'll be insignifant to have any major effect on the temperature.
    Certainty not a "major" effect as compare to the case of the diesel internal combustion engine where the rise in temp is sufficient to ignite the fuel.

    It's just a minor effect.. maybe 0.5 or 1°C changes? No comment on the magnitude.. maybe some can feel, some cannot..

    I'm not trying to affect the sales of dyson fan.. there no need for me to convince anyone.

    It's just.. food for thought..

  10. #50

    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    Certainty not a "major" effect as compare to the case of the diesel internal combustion engine where the rise in temp is sufficient to ignite the fuel.

    It's just a minor effect.. maybe 0.5 or 1°C changes? No comment on the magnitude.. maybe some can feel, some cannot..

    I'm not trying to affect the sales of dyson fan.. there no need for me to convince anyone.

    It's just.. food for thought..
    While the air forced thru from inside of the hoop may be compressed but the air drawn by this effect is not! Hence, there's no effect on the temperature.

    Hope u can get the picture!

  11. #51
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    Default Re: Electric Fan without blade

    Quote Originally Posted by KiichiroToyoda View Post
    While the air forced thru from inside of the hoop may be compressed but the air drawn by this effect is not! Hence, there's no effect on the temperature.

    Hope u can get the picture!
    If you read carefully, I never said that the air drawn in around the loop will be compressed or heated. I'm referring to the air that goes thru the small gap which is drawn from under.

    As I mentioned compression, I presume that it's clear what I'm referring to. The air around the loop that is drawn by some multiplier effect doesn't get compressed at all.

    And, a gush of hot air mixed with surrounding air at RT will result in a net increase in overall temperature.. althou the magnitude maybe small, it is not correct to say that "there's no effect" overall.

    If the fan blows very hot air all over the place, dyson would not be selling it rite?

    It's just a very small effect.. BUT, some pple may felt it, when they are standing just next to the fan trying to embrace the strong air jet from the gap.
    Last edited by Limsgp; 3rd September 2010 at 12:59 PM.

  12. #52

    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    If you read carefully, I never said that the air drawn in around the loop will be compressed or heated. I'm referring to the air that goes thru the small gap which is drawn from under.

    As I mentioned compression, I presume that it's clear what I'm referring to. The air around the loop that is drawn by some multiplier effect doesn't get compressed at all.

    And, a gush of hot air mixed with surrounding air at RT will result in a net increase in overall temperature.. althou the magnitude maybe small, it is not correct to say that "there's no effect" overall.

    If the fan blows very hot air all over the place, dyson would not be selling it rite?

    It's just a very small effect.. BUT, some pple may felt it, when they are standing just next to the fan trying to embrace the strong air jet from the gap.
    Let me clarify this:
    When I say the air being force thru from inside the hoop refers to ur term as the air coming thru the gap.
    When it is inside the main body, it is force thru the gap, the air upon exiting the gap is no longer pressurized, since velocity increase as pressure is lowered.
    Due to pressure differences, this results in air being drawn from the surrounding and thru the hoop which I believe is the so call multiplier effect mentioned.

    I never mentioned that the air drawn thru the hoop from the surrounding is compressed.

    I also mentioned earlier that the temperature increase(if any) is insignicant. In practical I mentioned no effect, this is base on having my fingers on the gap and face very near the hoop.

  13. #53
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    Default Re: Electric Fan without blade

    Quote Originally Posted by KiichiroToyoda View Post

    I never mentioned that the air drawn thru the hoop from the surrounding is compressed.

    I also mentioned earlier that the temperature increase(if any) is insignicant. In practical I mentioned no effect, this is base on having my fingers on the gap and face very near the hoop.
    You didn't mentioned the air drawn thru the loop is compressed, so did I. but you said "but the air drawn by this effect is not!" seems to imply that I said that the air thru the loop is compressed, hence, my reply to clarify against this.

    Like I say, with regards to whether one can feel the air is warmer, YMMV.

    Whether it is a fact remains to be seen.

    Yes, you can say that you don't feel the air is warmer, that could be true. but note that in SG, the RT don't ever seems to raise above 36°C. In other words, the RT is ALWAYS below body temperature.

    So, when a 29°C stream of air blows against you, heat is taken away, and you feel cooler then w/o the fan.

    The fact is when a 30°C stream of air (heated by 1°C) blows against you, heat is still taken away, and you STILL feel cooler then w/o the fan.

    It is very difficult to say whether anyone can really detect the change in temperature.

    If there is no change, fine lor.. I don't want to argue over this thing.. I'm not selling competitor brand..

    I'm only saying that "there is a possibility" that the air could be warmer then surrounding.

  14. #54

    Default Re: Electric Fan without blade

    Quote Originally Posted by Limsgp View Post
    You didn't mentioned the air drawn thru the loop is compressed, so did I. but you said "but the air drawn by this effect is not!" seems to imply that I said that the air thru the loop is compressed, hence, my reply to clarify against this.

    Like I say, with regards to whether one can feel the air is warmer, YMMV.

    Whether it is a fact remains to be seen.

    Yes, you can say that you don't feel the air is warmer, that could be true. but note that in SG, the RT don't ever seems to raise above 36°C. In other words, the RT is ALWAYS below body temperature.

    So, when a 29°C stream of air blows against you, heat is taken away, and you feel cooler then w/o the fan.

    The fact is when a 30°C stream of air (heated by 1°C) blows against you, heat is still taken away, and you STILL feel cooler then w/o the fan.

    It is very difficult to say whether anyone can really detect the change in temperature.

    If there is no change, fine lor.. I don't want to argue over this thing.. I'm not selling competitor brand..

    I'm only saying that "there is a possibility" that the air could be warmer then surrounding.
    For the record..I'm just "debating" with u on the air temperature being affected in anyway.


    Me also not selling competitor brand too.

    Quote Originally Posted by KiichiroToyoda View Post
    Don't bother, I already got the China knock off..don't waste your money.

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