Refrigerant is definitely NOT a consumable.
Whether your kitchen 'fridge, basement chest freezer, household air conditioner, or car A/C... The very basic principle is the same. Use a volatile chemical and trap it in a closed loop system. Use a compressor to pressurize it, which causes it to condense into a liquid. That compression generates heat which must be dumped out to the environment. Then, when much of the heat has been removed (via the finned condenser radiator just behind the grill), pipe the liquid to a restriction with much less pressure on the other side. As soon as the pressure is removed from the liquid, it instantly starts evaporating back into a gas. This TAKES heat to do. Then run that gas through a much smaller evaporator (which is inside the Ridgeline) which gets very, very cold. Blow air across the outside of the evaporator and the air gets cold, which is blown into the cab. When the gas comes out the other end of the evaporator, it has warmed up some and is fed right back into the compressor pump to be squeezed back into a liquid.
If the system doesn't leak that volatile chemical out (the Freon or R-134A or whatever), it should be good for the life of the car.
Unfortunately, a leak is just one thing that can go wrong. My last A/C failure was due to the electric clutch on the nose of the compressor going open.
But if recharging the A/C system made it work again, I think you've found the problem. If I were you, I'd just wait it out now. See how long this recharge lasts. If it only lasts a few days then you have a pretty good leak. If it lasts a long time, then you have a decision to make regarding how long you're planning on keeping the car and how much the recharge kit costs.
