# What do I need to understand about PSI for a small air compressor? **URL:** \ **Category:** Factual Questions\ **Created:** [February 21, 2012, 12:21am UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476 "2012-02-21T00:21:12Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [February 24, 2012, 7:17am UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/21 "2012-02-24T07:17:31Z")
> [@Stoid](#): > > I’m only talking about the kind of blow you get from cans of air. The air being “blown” out of a small pump isn’t that forceful? Seems like it would be…maybe it would peter out quickly, but so do air cans, actually. A few good blasts and they lose force, you have to wait a while. > > I LOVE the way air cans work, but I can’t stand the incredible waste and cost of them- it seems strange that the same action can’t be created in a handy little compressor… The small air compressor without a storage tank will not blow anything. The compressor prodces a small volume of air. Put that air into a closed outlet, a tire or tank pressure can build up. But with a blow nozzle on the outlet of the compressor no pressure will build up and the compressor produces only a small volume. I manage trying to wash dirt off the side of a building with water on a hot day. Your small compressor would be like using a teaspoon. Canned air would be like using a large picture of water. And an air compressor with a tank would be like using a bucket with a hose replacing the water used. The size of the hose would compare to the compressor size. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [February 24, 2012, 6:56pm UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/22 "2012-02-24T18:56:14Z")
There’s an [oiless one with a 3 gallon tank on sale for $39,](http://manuals.harborfreight.com/manuals/97000-97999/97080.pdf) usually $80… will the 3 gallon tank do the trick? Where does the air come from that goes in the tank? Does the compressor suck it in and hold it? The manual says: > [@](#): > > tO PREVENt ExPLOSION: use only clean, dry, regulated, compressed > air to power this tool. do not use oxygen, carbon dioxide, combustible > gases, or any other bottled gas as a power source for this tool. I thought the air compressor pulled air from the environment and compressed it, what am I missing? The link, by the way, is to that manual. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 24, 2012, 7:07pm UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/23 "2012-02-24T19:07:41Z")
> [@Stoid](#): > > There’s an [oiless one with a 3 gallon tank on sale for $39,](http://manuals.harborfreight.com/manuals/97000-97999/97080.pdf) usually $80… will the 3 gallon tank do the trick? > > Where does the air come from that goes in the tank? Does the compressor suck it in and hold it? The manual says: > > I thought the air compressor pulled air from the environment and compressed it, what am I missing? The link, by the way, is to that manual. They must have copied and pasted that warning from one of their air tools, without really thinking about it (I would guess they can’t read English). Yes, compressors compress air. BTW, I have one of these (or a very similar one, from Checker Auto), and it works GREAT. I’ve used it for many years. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [February 24, 2012, 7:27pm UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/24 "2012-02-24T19:27:11Z")
It may be overkill for your use, but I have a couple of [these](http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW) for computer dusting and they work very well. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [February 24, 2012, 7:50pm UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/25 "2012-02-24T19:50:12Z")
> [@beowulff](#): > > They must have copied and pasted that warning from one of their air tools, without really thinking about it (I would guess they can’t read English). Yes, compressors compress air. > > BTW, I have one of these (or a very similar one, from Checker Auto), and it works GREAT. I’ve used it for many years. So this one will do the blow thing I want, seeing as how it has the tank? > [@yoyodyne](#): > > It may be overkill for your use, but I have a couple of [these](http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW) for computer dusting and they work very well. I don’t know about overkill, more overprice. The one I’m looking at is $39 with the coupon, and that’s about the limit I’m willing to go, plus I want it to multi-task: inflate tires as well as blow. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [February 24, 2012, 8:00pm UTC](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476/26 "2012-02-24T20:00:11Z")
> [@Stoid](#): > > I don’t know about overkill, more overprice. The one I’m looking at is $39 with the coupon, and that’s about the limit I’m willing to go, plus I want it to multi-task: inflate tires as well as blow. Well, that one only does dusting not tire inflating. I feel like starting a thread on how I want to buy a new Mac Air for no more than $49.95. [Previous page](https://boards.straightdope.com/t/what-do-i-need-to-understand-about-psi-for-a-small-air-compressor/613476.md?page=1)