Sedalia Dave Posted December 9, 2020 Share Posted December 9, 2020 Link to comment Share on other sites More sharing options...
BLACKFOOT SASS #11947 Posted December 9, 2020 Share Posted December 9, 2020 That makes my head hurt! Blackfoot Link to comment Share on other sites More sharing options...
Marshal Mo Hare, SASS #45984 Posted December 9, 2020 Share Posted December 9, 2020 But the fog is not on the inside of my windows. Link to comment Share on other sites More sharing options...
Alpo Posted December 9, 2020 Share Posted December 9, 2020 About halfway through he explains that WHEN THE HUMIDITY EXCEEDS 100%. That's when I stopped watching. It is impossible to exceed 100%. As to what defrosts quicker, in my experience you should run air through the air conditioner. The heater blows hot air, but the air conditioner blows dry air. Link to comment Share on other sites More sharing options...
Rye Miles #13621 Posted December 9, 2020 Share Posted December 9, 2020 Sorry I couldn't get through the first two minutes!! Link to comment Share on other sites More sharing options...
Charlie Harley, #14153 Posted December 9, 2020 Share Posted December 9, 2020 As someone who’s spent his career engineering HVAC and manipulating air’s psychometric properties, his video is about 50% right. His “wet towel” analogy and the two cubes of hot and cold air are the best explanations of relative vs absolute humidity I’ve ever seen. They are getting forwarded to colleagues who teach engineering. As to his conclusion about the best way to defog a windshield, it will work under a specific set of circumstances. However, there are a lot more variables at work, and as they change, the optimal solution changes. The best overall option is still to turn on the defroster at a high temperature, get out of the car, and lock the door. 1. Heating the air lowers the relative humidity, thereby drawing condensation off the glass and back into the air. 2. Hot air will heat the glass, thereby melting frost on the window’s outside. His method could actually aggravate a frosted condition. 3. Hot air makes the car more comfortable for when you come back to it in ten minutes and drive away. And now back to our regular programming... Maryanne! Link to comment Share on other sites More sharing options...
Sixgun Sheridan Posted December 9, 2020 Share Posted December 9, 2020 4 hours ago, Alpo said: As to what defrosts quicker, in my experience you should run air through the air conditioner. The heater blows hot air, but the air conditioner blows dry air. Most automotive defrosters kick on the A/C pump as well. I used to own a very gutless Dodge Neon that almost came to a stop whenever I threw the lever over to DEFROST. Link to comment Share on other sites More sharing options...
Cypress Sun Posted December 9, 2020 Share Posted December 9, 2020 4 hours ago, Charlie Harley, #14153 said: As someone who’s spent his career engineering HVAC and manipulating air’s psychometric properties, his video is about 50% right. His “wet towel” analogy and the two cubes of hot and cold air are the best explanations of relative vs absolute humidity I’ve ever seen. They are getting forwarded to colleagues who teach engineering. As to his conclusion about the best way to defog a windshield, it will work under a specific set of circumstances. However, there are a lot more variables at work, and as they change, the optimal solution changes. The best overall option is still to turn on the defroster at a high temperature, get out of the car, and lock the door. 1. Heating the air lowers the relative humidity, thereby drawing condensation off the glass and back into the air. 2. Hot air will heat the glass, thereby melting frost on the window’s outside. His method could actually aggravate a frosted condition. 3. Hot air makes the car more comfortable for when you come back to it in ten minutes and drive away. And now back to our regular programming... Maryanne! Keep in mind that if you're going to turn on defroster at a high temperature, get out of the car, and lock the door.....try this at home 1st and make sure that you have a real key, not just a remote, that will unlock the doors. Ask me how I know. Link to comment Share on other sites More sharing options...
Assassin Posted December 9, 2020 Share Posted December 9, 2020 Buy a Tesla, the electric defrost works instantly. One of the doctors has one at work, they do have a few good options. Link to comment Share on other sites More sharing options...
Wallaby Jack, SASS #44062 Posted December 9, 2020 Share Posted December 9, 2020 5 hours ago, Charlie Harley, #14153 said: Maryanne! ....... I agree ... she could cook ... Link to comment Share on other sites More sharing options...
Hardpan Curmudgeon SASS #8967 Posted December 9, 2020 Share Posted December 9, 2020 6 hours ago, Alpo said: About halfway through he explains that WHEN THE HUMIDITY EXCEEDS 100%. That's when I stopped watching. It is impossible to exceed 100%. Actually, relative humidity can exceed 100%. Relative humidity is the ratio between the amount of water in the air versus the amount needed to completely saturate the air given the current temperature and barometric pressure. Saturate in this case means the point where water starts condensing out of the air because it can't "hold" any more. This is a "more or less" point rather than a clearly defined point, as you can feel damp and see water condense on surfaces far below 100% humidity. If the air is clear, providing few sources of nucleation where water can condense, and the temperature and/or pressure change very rapidly, the air can become supersaturated, meaning the humidity can exceed 100% until enough water condenses out. However, this should only be a case of a few percentage points. I remembered this from a meteorology class I took in 1969, but did have to look it up. Link to comment Share on other sites More sharing options...
Pat Riot Posted December 10, 2020 Share Posted December 10, 2020 Jees...H... I had the strangest desire to snap his little flippy girlie fingers. After all that I learned nothing...except I did debate myself on the best way to crack girlie fingers that flip about in the air...Snatch and snap? Grab and crackle?.... Sorry...just being honest. Link to comment Share on other sites More sharing options...
G W Wade Posted December 11, 2020 Share Posted December 11, 2020 Didn't watch your video but the topic reminded me of a post some where else. The poster wanted to get in touch with the person who recommended putting sheets of sand paper under your windshield wipers to remove ice!!!! GW Link to comment Share on other sites More sharing options...
Linn Keller, SASS 27332, BOLD 103 Posted December 12, 2020 Share Posted December 12, 2020 At one time, Ford Motor Company offered a gold windshield for their luxury cars. Claimed it was a one molecule thick layer between the windshield laminations; said a current passed through it to heat the windscreen, clearing it of frost and fog, went on to further claim this method was used on passenger jets. As this was a poster in a dealership, and anything at a dealership is engineered to part the customer from cash money, I regarded it as possible, but not worth buying a Crown Vic just to get a neat nifty windshield! Link to comment Share on other sites More sharing options...
Chili Ron Posted December 12, 2020 Share Posted December 12, 2020 Howdy, I did a quick search and that system is popular in Europe. Available on fiesta on up. Says it was 250 back in 86. Just a little too expensive??? Best CR Link to comment Share on other sites More sharing options...
Utah Bob #35998 Posted December 12, 2020 Share Posted December 12, 2020 21 minutes ago, Chili Ron said: Howdy, I did a quick search and that system is popular in Europe. Available on fiesta on up. Says it was 250 back in 86. Just a little too expensive??? Best CR Yeah too much$ Link to comment Share on other sites More sharing options...
Chili Ron Posted December 12, 2020 Share Posted December 12, 2020 Howdy, Seems like someone could make a cover for the windshield that would just pull off and take the snow and ice with it. Seen anything like that?? Best CR Link to comment Share on other sites More sharing options...
Alpo Posted December 12, 2020 Share Posted December 12, 2020 33 minutes ago, Chili Ron said: Howdy, Seems like someone could make a cover for the windshield that would just pull off and take the snow and ice with it. Seen anything like that?? Best CR Yes I have . I believe it is called a garage. Link to comment Share on other sites More sharing options...
Sedalia Dave Posted December 13, 2020 Author Share Posted December 13, 2020 10 hours ago, Chili Ron said: Howdy, Seems like someone could make a cover for the windshield that would just pull off and take the snow and ice with it. Seen anything like that?? Best CR Hundreds of them available on Amazon Link to comment Share on other sites More sharing options...
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