Are large air ionisers any good

[cybernut]

I'm thinking of getting one of those large floor standing air ionisers for my office which atm is a shed in the back garden to combat the problem of dust build up, bugs, spiders and such, but are they any good or a waste of money.  Any advice welcome.

[ATH019]

Here's my two quid's worth.  I had one of those once which wasn't that great, but in your case wouldn't do anything about spiders and such.  Why not open the windows now and then?

[McGaskil]

Don't know about the more expensive industrial one's but ordinary domestic ionisers are a fwot and as other poster said, won't prevent bugs or cobwebs, etc.