Air compressor issues...

Was at my neighbours this afternoon helping him change tires and wheels on one of his tractors. Anyway, he has two compressors in his workshop, an old 20gallon one and a new fangled 60 gallon upright, the new 60 gallon one always produces a very wet airstream, use a blow gun or impact wrench and there is always water out of the exhaust or nozzle. He drains maybe a gallon a day out of the tank and no longer leaves the air compressor on when it is being used. His old 20 gallon compressor is on all the time and never seems to have much water to drain out of it.

Any ideas why. Compressors are in the same building.please

Logically speaking, the moisture has to come from the air taken in by the compressor - unless it is somehow liquid cooled. Therefore, moisture coming from the newer compressor must be condensing from the air. The same happens with the older compressor - however, look it over carefully. It must have a water separator in the system somewhere. It also makes a difference where the air is drawn from to power tools. If it is drawn from the top of the tank, it will contain less moisture than if it were drawn from the bottom of the tank. Quite possibly, the newer compressor is drawing from the bottom of the tank to control water buildup, and is meant to be used with a water separator.

Larger tanks have enough surface area that they stay cooler and condense more water. there are valves that can be purchased that vent condensate from the bottom, and water separators to put in the air line as well. Look up EDT 25 on this link. Jim
One source

The water in tank is from moisture(humidity) in air. The bigger compressor pulls a larger volume of air there for more moisture. They do make air dryers that you can put on air compressor to stop the moisture from going throught lines to air the tools.

Separator
one that is pretty good. Less is not best. Jim

Lots of variables here, not a lot of information, but...

The reason the bigger compressor is making more water is because it is taking in more moisture laden air.

As the air is compressed, the air/water mix is heated. When the hot mix enters the tank it begins to cool and some of the water condenses to the cooler inside of the tank, runs down to the bottom and waits there to be drained.

But since the air still has some heat and moisture left in it as it leaves the tank, the remaining moisture continues to condense on the cool inside walls of the delivery pipes and hose. That's when the liquid water gets caught up in the moving air stream and comes out the end of the hose.

So, what is the solution?

Cooling the air so the moisture drops out before entering the line is the most efficient method, but also the most costly, not really worth it for a home shop application.

If the shop is plumbed with air lines, all the lines need to slant upward away from the tank so the water tends to drain back to the tank. If this is not possible, there needs to be drop legs at the low points to collect and drain the condensation.

Finally, install water trap filters near the point of use. Traps will only collect liquid water, so installing them near the tank won't do much good as the air will still be warm and carrying water vapor. Also, all connections from the lines need to come off the TOP of the line, not the bottom.

The automatic timer drains work well for keeping the tank and drop legs drained.

I installed a new to me compressor last winter. I built a water separator myself then added on a commercial one. The one I built consists of eight feet of 3/4 copper pitched down from the compressor running into a copper tee. From the tee the copper runs up two feet then turns and runs back down two feet, then into the commercial cleaner/dryer /regulator. From the down leg of the tee is a leg that drops one foot to a drain valve. I get a lot of water from it.