duty cycle- heat limited?

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yes i know i am probably going out on a limb here buuuut...so a duty cycle of 20% sucks. yes i know spending a few hunderd more will get me a better duty cycle with all other variables the same or similar in a different model.the first thing that comes to mind in the electrical sense of duty cycle to me anyways, is heat. therefore, would it at all be possible to pull air through say a HEPA filter and ducted to the fan, then blown through the welders case and increase duty cycle through better heat dissipation? i know this isnt one of those orthodox questions and many will just doff the idea off as an uninformed newbie trying to get more than what he pays for, but i do know that if i even installed such a setup (which i probably will anyway just to keep things clean, cool, and lower maintinence) it should not hurt anything. dont worry guys i am used to the wierd looks and criticism. i get a lot fo far-fetched ideas. some work and some dont. i would just appreciate any thoughts and comments on what your thoughts would be on running 40-50cfm of fresh, filtered air through a lincoln sp135 plus. also running a small power inverter to a 12v DC fan- how the inverter connected inline with (but before) the power supply would affect the flow of current to the power supply, or would sticking to an AC current fan keep the current flow in check and help the welder not notice a difference. thoughts, comments.  Just a guy trying to learn!
Reply:I think you are correct about the heat being the issue. What you suggest would probably get you slightly longer duty cycles. One thing most people overlook is the electrical supply to the welder being rated to handle full output on say a 100 % duty cycle machine. When I wired the garage for my welder that duty cycle came into play and determines wire size minimums. I don't have large duty cycle machines. If your running 100% duty cycle machines, that draw big time amps, your running huge wires from the box to your outlet. You may not mind having battery jumper cables size wire running in an out building but it doesn't look so good in a garage. If you machine has a smaller duty cycle then the wires can be sized smaller because the machines duty cycle allows the wires to cool also.
Reply:good call mate! see i get these wierd ideas but sometimes overlook some mundane detail that usually costs me something stupidly large. like an engine- or in this case my buddys garage . he might not be pleased with that hehehe. anyways for what its worth i dont think ill really be going over 20% duty cycle anyways but the extra protection and piece of mind will set me at ease. plus not having to clean it out as often is a bonus. any thoughts on a small DC converter screwing up the current flow to the welders power supply? i highly doubt it but i was just trying to think of all angles. thnaks again for the input!Just a guy trying to learn!
Reply:Just wanted to throw my thoughts in here .. I have a HF 151  120 AMP MIG .. It has a fan in it for colling.. and I have 10 gauge wire goingfrom the breaker box to the outletIt is rated at 15% duty Cycle at 120 Aand I have used it , still learning , and practicing , at anywheres from 50 amps to 120 amps .. Mostly on 50 and 75 amps .. And it seems like I have welded more than long enoughto kick of the MIG due to overheating .. But it doesnt .. I asked a " certified welder" what period of timethe duty cycle was based on .. and he saidit was based on an  hour.. But , in my online courses it says its based ona ten minute period .. which from a elect tech viewpoint,makes more sense to me .. Sooo .. which is it ?? and even at say 20% for 10 minutes..  thats 2 minutes of welding and 8 minutes of cool downtime .. not sure about anyone else .. but I'm hard pressed to weld 2 minutes straight ..  or even  3 minutes on and off over, say a 12 minute period .. Soo .. unless one was in an commercial environment .. where every welding moment was money ...   It seems like the 20% ish duty cycle would be fine?? BUT, I would sure like inputs on what the time period is .. Thanks all .. Randy
Reply:All the techs I have spoken to from Lincoln, Miller, HTP, etc. state the the duty cycle of a machine is based on the 10 period.  Dont know where the quy got that it was based on an hour.A few of my toys !LinuxMintManjaroMiller Roughneck 2E Lincoln WeldPak 100HTP MTS 160 Chicago Electric 80amp Inverter   Victor O/A
Reply:LoL an hour...hehe  Well I think I have heard it all.  As far as welding goes its 10 minute, and as far as general electrical systems its also based on 10.  Not sure where the 10 minute figure comes from actually, but thats what it is.  I would think you can help your duty cycle by removing heat from that unit.  Ive never actually tried.  However, I have heard of cases where with generator machines where you often mount on a truck and there are air flow restrictions. and a fellow had the machines air flow blocked he lost a certain amount of duty cycle due to lack of airflow.  It only makes sense the reverse wiould be true.  Good luck anyways, and I like your ideasCHRIS
Reply:any thoughts on a small DC converter screwing up the current flow to the welders power supply? i highly doubt it but i was just trying to think of all angles.