Does anyone have and idea about the tumble dryer Condenser Kits? It is a hoax?

Answer 1

Well, it's not a hoax, They are used to condense the moisture from the vented hot air and return the dry hot air to the dryer. This is supposed to reduce costs in heating the air to dry your clothes.
I personally don't know what the savings would be but a lot of the newer dryers are coming out with the condensers built in. The kits can be bought and installed on your older dryers.