Is it common practice to hook up the dryer vent to an ERV system?

Seems like alot of BTUs going outside...

Ian.

It is a lot of BTUs going outside, however if you hook up a dryer to an ERV you will plug it up in a week or two. Unless you can seriously filter the exhaust I wouldn't try it. I have seen a dryer ducted through a 20x20x2 inch filter setup, then maybe? I would bet it would void the warrantee on the ERV no matter what was in front of it filter wise.

What about a long vent that's fitted with cooling fins to disperse as much heat as possible before it exits the building? Would that be a problem in the summer when you don't want the heat? I guess you could have a short insulated vent run for the summer and swap the connection as needed.

The problem with a longer duct is it allows the exhaust air to cool and condensation will collect on the sides of the duct causing the lint to stick to the side and build up a nice layer (I am speaking from experience). If you don't mind cleaning out the metal duct at least once a year, this works. I had a system when we were in the heating season I ducted the exhaust out and back in about 60 feet of metal duct, in summer I just re-connected the dryer directly to the outside exhaust. I could easily get at the duct and drop it and clean it out.