carbon filters

whats the life span on carbon filters, i have one running for about 4 years now and i dare say its not working as it should, going by the smell coming down from the roof-space, right enough its very warm today, wander should i close the hatch over and hope nobody goes up to their roof-space next door or the door after,
any ideas?
any roofspace growers here?
should i replace the filter maybe or in hot days like today it'l stink out anyway

Get a new filter ASAP I replace mine every 2-3 months

holy fuck, cheers think i will

Ever consider building yourself a carbon filter? It's a fairly simple DIY trying to create a container that pulls air that passes through activated carbon. Just make sure you build something of similar size to what you have now; can't use a 5 gal bucket with a 4" inline fan. You would only have to replace the activated carbon every few months instead of buying a whole new filter.

TD

this sounds good as im not to rich at the mo, will have a look on line for some carbon, could maybe get the old carbon out of the one i have and replace it

The actual filter screens should probably be replaced as well or beat and cleaned out at least. I set up a can fan and filter for a friend last week. It looks like those things are built Ford tough and stitched shut pretty well. Maybe you can reconstruct the filter you have now so you can change the carbon and filters periodically