Costco blog/discussion forum

If you have asthma or allergies, one of the first things to do is make sure you are breathing clean air. One way to do that is to purchase a Therapure 300D air purifier, available in Costco warehouses (Costco Item number 176245, $129.99 in July 2008; this item currently has a manufacturer's instant rebate of $30 making the total $99.99).

A standard exists to quantify how well an air cleaner works. This standard is called CADR, clean air delivery rate. The standard setting body, AHAM, publishes a list of certified air cleaners, along with their effectiveness, measured with the CADR number. Therapure claims a CADR of 180 (at high setting), however the AHAM database does not list Therapure as a certified manufacturer. Furthermore, CADR numbers are measured for three contaminants separately: dust, tobacco smoke, and pollen. So, it isn't clear what Therapure is referring to when they claim a CADR of 180.

As usual, Costco is offering the best price I can find. If you buy this direct from the Therapure web site, it will cost $150 plus shipping. If you hunt around the internet, most other sites will sell it for about $175.