I just recently joined in this forum.
but before this, I read this lowyat forum several times.
when I saw this discussion, then I think I need to give my opinion.

In the begining, Mr. Onemorething is giving technical explanation about air purifier.
he give you suggestion this and that. You'll feel he clarify your problem.
this is good and I'm respect him.

But if you open your mind...
seems he trying to do "BRAINWASHING". I'm sorry to say this.

people become more confuse and they feel that any HEPA filter
is not good enough as his "TRUE HEPA FILTER".

I'm not expert, but just watch this video:



He is Dr. and I think he has reputation to talk about HEPA filter,
because he works on Sinus center.

what do you think about suggestion from Dr. Jeffrey E. Terrell & Mr. Onemorething?

simply, right?
even Dr. Jeffrey E. Terrell suggest HEPA filter that cost only $25 is enough for your house.

keep open minded, just receive any information and judge it by yourself.
"follow your heart..."