As someone who lives in a granite 'high Radon' zone, it might be moot to point out that an 'added on as an afterthought' fan will very likely not work anyway. Radon is 8 times denser than air, tends to collect in basements and is often expelled from a sump or collected from under the slab before it can get in the dwelling.

http://www.seered.co.uk/radon52.htm makes interesting reading.

The client may be better off [peace of mind-wise] by investing in a test kit rather than motor monitoring.

http://www.radonzone.com/ ... is just one I found.

Last edited by Alan Belson; 10/09/10 02:42 PM.
Wood work but can't!