I've always been more than a little suspicious that the units which try
to transfer moisture between airstreams will also transfer other stuff
(dissolved in the moisture) between airstreams, which you might rather
exhaust. An obvious example would be ammonia fumes from cleaning
products.

I'm also innately suspicious that this type of core is a better breeding
ground for unplesant life-forms.

--
Cats, Coffee, Chocolate...vices to live by