My question has to do with charcoal filters. How long do they typically last and is there a way to replenish or recycle them?
The life of charcoal filters varies greatly based on size and usage but a good rule of thumb is not to run them more than two years. Most of the manufacturers of the units will tell you to change them every 18-24 months no matter what, but if you have a big room, with your exhaust blowing through the filter 24 hours a day, you might want to replace the filter every calendar year. The pores between the pieces of activated charcoal eventually become filled with odor particles, moisture, dust and other particulates limiting the ability of the charcoal to clean your outgoing air.
Rather than replacing and repacking the new activated charcoal yourself, I recommend purchasing a replacement filter and installing it according to the manufacturers’ instructions. Unless you’re an expert in how to pack the filters properly while avoiding air pockets, do yourself a favor and stick to the manual.