Good air filtration

I have noticed long before my adventures with coal heat that filtering the house air has many health advantages for me. this is one of the many reasons why I choose a ducted whole house air system as I can estimate total changes per hour and the filtration level I want. Of course it can be done by hydronics or even a simple fire place but to filter the house becomes an additional consideration. The subject of filtration efficiency has been covered elsewhere on this forum

How to connect cold air return to Koker

and other examples. I used to have a winter hacking cough that only went away when I used a MERV 11 filter or better. What I love about the LL Anthraking as I start to get it set up now is the 1800CFM squirrel cage fan and the way it is integrated into the coaltrol (smooth as butta). There is an input with provision for a 20x20" 1" filter on which I was planning to put a Filtrete 1900 (about MERV 12). As I spent about 10 years in pharmaceutical clean room operations using filters which were about MERV 20 (expressed differently then and now), I was aware of the desirability of the more the better filtration systems. Now in dirty homes (comparatively) you reach the point of diminishing returns but sucking some bacteria and other fumes and smoke even unattached viruses has many health advantages. I pay $20 per filter and in about a week it is dirty. So 4" filters, prefilters other ideas are appropriate here. Any comments.

Electronic filter as a pre-treatment followed by a filter of your choice...

and the electronic filter of choice for this air flow is???????

I don't know, I use an old bath towel. But, this is Freetown. No, I'm serious, I use an old bath towel.Of course I don't suspect it's electronic anything.

I like the aprilaire...
http://www.aprilaire.com/index.php?znfAction=ProductsCat&category=cleaner

Thank you for the advice. Fred, we use old bath towels and worse to wash down horses. Twice a year I have to unblock the clothes drier exhaust vent. I just have a suspicion that will not help my coughing attacks. Geez, they breed them tough at Freetown.