How does everyone here use and store their air compressor? I only use mine (5hp, 21gal) every few months, so I let it pressure up and use it for what I need and then when I'm done, I vent the air out and open up the T-couplers so it stays open to ambient air. Do I need to vent the bottom to let out any condensation if I have it open to air temp? Is it better to let it stay pressured up for a while? I check the oil level and make sure it's good but haven't changed it out since new 6 years ago.