Why are CFM ratings BS?

gentlemen welcome back to the show you can't dazzling ones brilliance baffle them with [ __ ] and Yura was to the vagaries of marketing wanker tearing turn around and whammo reitman nuts I can't believe the utter gall of tool companies what make air compressors in their rating systems the mind boggles at how deceptive it is if any or anything like me it oddly strikes yeah that any compressor can never keep up even the highest rated compressor can virtually never keep up with the lowest rated tool and okay so there's gonna be some hyperbole in the rating so it's going to be some tweaking just so forth however there was a class-action lawsuit in the early 2000s what brought two term campbell haas field and develop lists and I think Coleman or Kenneth some other brand that were over rating their compressors and they got their their pecker punched and they had to settle out of court so we figured that the ratings on compressors would at least have a modicum of accuracy I on a year now we cannibalized the Campbell Haas feel of compressor and I replaced it with a roll air the that's bull this is just you know we don't I don't use that much air here so this is fine for me it's just a plug in unit hundred and fifteen volts rated at four CFM at 90 psi plenty of air to run little things even just a bust nuts with the a good dug of gun the reason I bought this one it's a good it's a good name brand to kind of Maiden aus na so in North America and also I like to cultivate really well not relationships but I put a premium on people not lying to me so I buy tools that are that has some ethics essentially that aren't all about the marketing wanker tearing that is you know stepping over their grandmother to sell a tool so I like to hit these I pay extra because they don't [ __ ] lie to me so the role they're paid a little extra because I fingered hey you gonna lie to me boy howdy was I wrong alright here's the test we get the FAP off 3.2 CFM at 90 psi average air consumption now this court bought this when I was young dumb and full of [ __ ] of course the Jacob Chuck got to be better than the collet right right yeah wrong never get a Jacob's Chuck die grinder same reason you never get a Jacob's Chuck milling machine okay so essentially what we're gonna do so this is 3.2 the compressor is rated for 4 CFM at 90 psi sigh so right now look have a have a look here huh see see I'm plugging in the compressor if you have a look at the gauge in the tank is 110 psi maybe a blonde went over now we're gonna run this and we're gonna see how much CFM it takes and if the compressor can keep up he or tact a parallax error aside that compressor cannot even come close to keeping up to the die grinder let's see you again now we've we're at 120 psi we're gonna try it again okay we topped out at 3.4 CFM negating the I'm right in line so I'm negating the parallax cameras a little off-kilter and test ii as with the first we saw 3.4 CFM cubic feet s standard cubic feet per minute of air through this flow meter and the compressor couldn't keep the pressure up to 90 psi just couldn't keep up it was dropping and dropping and dropping and we saw as the the pressure in the tank reduced so too did the flow makes a sense because there's a pressure differential there the higher the pressure differential the faster the flow okay so let's see how much air that this compressor actually can output at 90 psi what we're gonna do is give her the old French tickler just a lee trevino feather touch trottle how much hair is going through here measure it till we get steady state at 90 psi on the gauge and then we can back read how many CFM is actually flowing through that tool that'll give us the actual CFM that this guy is outputting that the compressor is outputting at 90 psi catfish there's models [Music] despite his bold-faced hyperbole of four CFM at 90 psi we saw a 90 psi it was only outputting but but between 0.8 and 1 CFM so we'll say 0.9 CFM that is a long way from 4 CFM what the [ __ ] over so if the ratings are so out of whack how are you supposed to buy a compressor what will run a given air tool now the rating systems what they're doing and this is in my opinion vile obfuscating I mean baffling people with [ __ ] is essentially what this I ain't no dummy and this they pulled the wool over my eyes for years I had no idea this is I just learned of this and interesting also comment in the patreon is that that's you know we get people from all over the world putting into the beer front Germans even and they in Germany they have to say what the rating is and there's a word there I forget what it is but it means essentially sucking power what they are doing when they're rating the CFM is they are rating how much flow they're getting at the inlet at zero psi gauge which is 14.7 atmospheric so they're measuring how much flow knot is coming out and going into your tool but how much flow is going into the compressor this is going to angry up the blood so if and you've been to beer festivals and eaten nothing but poutine you're gonna want to look away hi it's too late for me what their because they ain't lyin to you they're just given your alternative facts so what they're not telling you is the CFM that you see they're actually using s CFM which is standard CFM meaning that's taken at 14.7 PSI which is atmospheric pressure at sea level at a given temperature say 25 centigrade whatever 78 Frankenstein cubic feet per minute that means they're enacting Boyle's law to baffle you with [ __ ] but a flaw of course the unified gas law No Boyle's law piece up 1 V sub 1 is equal to piece up to V sub 2 where P is pressure and V is volume so we look at this now on the first side we get 14.7 PSI times the volume which is 4.0 CFM we take it as understood that we're doing this over a minute so that's going to be 4 cubic feet not per minute we can omit that so that gives us 15 times 4 which is 60 I'm going dimensionless here I'm not doing dimensional analysis so you go ahead and take a puck couple marks off there no worries I can handle it and the pressure too of course is going to be 90 psi what the tool uses plus that 14 that's going to give us right around 100 psi V sub 2 is what we want to find out which is the actual flow to the tool now because we have this very powerful tool here the equal sign that means on both sides of the equation everything has to be the same we want to get rid of that we have to divide on both sides so that V sub 2 is equal to 0.6 C fm 0.6 what the [ __ ] kind of tool you're gonna run with that partner wind storm I hear you you don't believe me I could scarcely believe it myself that a company let alone an entire industry so brazenly pulling the wool over consumers eyes over our eyes it's incredible I'm gonna I'm gonna prove it to you that that is how they are rating their compressors because what we're gonna do is we're gonna watch the gauge down here we're gonna have it set at 90 and we're going to open this valve here and read off how many CF we're getting no what happens is at 90 psi of course the air is compressed quite a bit when it goes through this valve up here it's open atmosphere that's zero psi fourteen point seven but a zero on the gauge so when we open this up we're at zero pressure the gas is going to expand that's going to give us our rated flow even though it's at zero psi and you can't do any work with it but that is exactly how they are getting the reading understandably this is confused I didn't figure it out myself until I saw it with my own two eyes and tested what was going on so effectively at zero psi there's no work being done here it that compressor is able to with 90 psi in the tank is able to deliver three point two four point five three point five CFM at zero psi so if you want to use a tool let's rate it at three point two at 90 psi you must if you want to size a compressor to buy you must use Boyle's law they there's no you're never gonna be able to keep up to a tool like this on a compressor rated for the same amount because the rating is complete and utter [ __ ] in furtherance to the [ __ ] if you wanted to run this tool Boyle's law right a 100 psi are a little more than 100 psi times 3.2 CFM divided by fourteen point seven that would give us right around 20 CFM of that standard cubic feet per minute rating on consumer compressors however real compressors that are used in industry they rate there's in the delivered CFM so if you were to buy a $5,000 ala scrap coal compressor what put out 20 CFM those are real CFM delivered at 90 psi to the tool so you could run all kinds of things off of that kind of power unit but on this kind of compressor consumer-grade compressors I mean you can't run anything essentially it will no consumer-grade compressor plugged into the wall will run a continuous duty tool it's physically impossible it will not supply the air that you need despite whatever ratings they want to walk on there it's complete and other douche beggary complete marketeering [ __ ] pisses me off what are you gonna do invent the new standard I guess Spanx for watching hey don't take any wooden nickels [ __ ] me keep your dick in a yeah

Channel: AvE

Views: 395,064

Keywords: air compressor, dewalt, milwaukee, rolair, ingersol, ir, test, atlas copco, review, tool, experiment, cfm, rating, air tool, husky

Id: cfjSm_ieRkE

Length: 13min 42sec (822 seconds)

Published: Thu May 23 2019