hello ,fellow cannabis.com user "bordom children of" ,
made an awsome diy carbon filter thread
http://boards.cannabis.com/grow-faqs...on-filter.html

The most costly thing will be the normal household ventalation type inline fan those will run 30-50 us dollars depending on where you buy them for a cheap one.

Other solutions that might not work as well is getting a masking scent such as one those plug in air-freshiners like an glade plug in or air wick that have a little fan in them and release smellstuff into the air . Place one in the grow area , one in the room that the grow area is in , and maybe 2-3 thoughout the house. Those things only cost a couple dollars us each.