5 ms·

I think it’s harder to go 80–100 than it is from 60–80. I’m both cases, you need to stuff the same volume of additional air into the tank, but in the 80–100 ca

I think it’s harder to go 80–100 than it is from 60–80. I’m both cases, you need to stuff the same volume of additional air into the tank, but in the 80–100 case, the resistance to the stuffing is higher. At least I think that’s how it works. Assuming spherical cows and an ideal gas.

ars 3y ago
In theory if the resistance to the stuffing is higher, then it also pushes the air out harder - i.e. it's a wash. Except that it's not, because when you compress air you heat it, and all the heat energy is gone. This is why compressed air is a terrible energy storage method. The hotter you heat the air (higher PSI) the more energy you waste.
- function_seven 3y ago
  Wouldn’t the air not be pushing against my piston? It’s already in the tank and the piston is being pushed by atmospheric pressure for the next gulp. Good note on the heat. I’ll wrap my whole setup in a blanket to recover that ;)
- raverbashing 3y ago
  It does heat and you do lose some energy there, but not enough to lose all of the compression applied
Someone 3y ago
It must be harder. If it wasn’t, you’d be able to get to arbitrary pressures with a constant force. So, in the extreme, if you can get the air to 15 psi with your lungs, you’d be able to get the air to 1000 psi with your lungs, too. Another way to see that is to consider two tanks at different pressures that are connected to each other, and ask yourself why air will flow from the higher pressure one to the lower pressure one.