Compressor recomendation

Still trying to wrap my head around this. So from the video I posted with the gentleman installing the B&M transmission cooler between the compressor pump and the compressor tank, he is trapping some water before it goes into the tank. Less water in the tank equals less water in the air?

Would this be correct?

Also, if I'm understanding you, a compressor pump that produces more heat than another pump, has no effect on how much water is generated? I'm trying to see if the transmission cooler really has any benifit?

How to read a physcrometric chart
https://www.brighthubengineering.com/hvac/41264-how-to-use-psychrometric-chart/

Physcrometric chart
https://www.engineeringtoolbox.com/docs/documents/816/psychrometric_chart_29inHg.pdf


If the trans cooler was removing moisture from the compressed air and draining it away before entering the tank, it would equate to less air in the tank, but not necessarily less air in the air system. Keep in mind that the air leaving that trans cooler would need to be a lower temperature than the temperature of the air lines in your shop, basically lower than the temp of your shop. If you were blowing ambient air across the trans cooler, the best you could hope for is a dewpoint slightly above the ambient temperature of the shop, and that assumes that the heat exchanger from the trans is large enough to reject all this heat which is unlikely. it appears to me that they are just exchanging the place that some of the moisture condenses from the tank to the trans cooler, without really affecting the moisture at the end of the system. It is akin to taking money out of one pocket and putting it in the other pocket, as nothing has really changed.

Remember, the air is basically at 100% humidity at almost any point in the system, and the only way to affect that is to lower the temp of that air dramatically to condense the water out, and then let it warm back up to room temp, or to run it through a desiccant.

Yes, you are correct. The amount of heat the compressor generates has absolutely no impact on the amount of moisture. The only factor is the compression ratio compared to ambient air. If the compression ratio is 10:1, then the grains of moisture in the compressed air will go up by 10 times. You can as others have stated, spin the compressor slower, and that will make less moisture over time, but it will also make less air over time, which means that you have to run the compressor longer, which then makes the same amount of moisture over time. It also does not change the fact that the air will still be saturated (100% humidity) at the air drop in the shop.



Regards, John McGraw
 
i've tried just about everything over the years . the 400 dollar HF dryer is the only real improvement i've had . filters before and in the booth helped a lot but the cooler did the trick . now days i have the luxury of picking the days i paint . i'm not sure how many more i will do . after 45 years i've grown a little tired of it .
 
This was very interesting and educational discussion about the functions of an air compressor, and how moisture / water is made.

Is there any other advantage to using the physcrometer chart other than knowing how much moisture will be made at a given ambient temperature?
 
This was very interesting and educational discussion about the functions of an air compressor, and how moisture / water is made.

Is there any other advantage to using the physcrometer chart other than knowing how much moisture will be made at a given ambient temperature?

It just gives you an idea of the relationship to moisture and temperature. You can make a lot of assumptions about temp and moisture, but until you plot out the desired conditions, you really do not know. I use one almost every day as an HVAC engineer but for most people, it is just to give them a feel for the relationships. When you truly understand the relationship of temp and moisture, you can make good decisions about how to treat the air and what makes sense and what does not.

Whenever you design an HVAC system, you have to be able to predict the moisture in air at several conditions, as this affects the size of the equipment. A HVAC unit is rated in BTU's, but there are two types of loads associated with cooling, latent load and sensible load. Sensible cooling actually changes the temperature of the air, while latent cooling is how many of the BTU's are used up removing moisture from the air. The more latent load on a system, the less that is available to actually cool the space. We have to understand each job we do in order to properly size the equipment.


Regards, John McGraw
 
Lol dont read that. That is clearly an advertisement page. Only good compressor on that list is the quincy. Couple others are just ok. The rest are junk. Campbell hausfeld and coleman....really? Lol. Quincy, champion are very good and more common. There are many others.
 
I have a 2005 Eaton compressor that's been very reliable. I just purchased a 10hp for work but haven't received it yet.
I've been very satisfied with the Eaton.
 
Back
Top