TOPIC: Dryer vent has 3 90's and quite a distance to travel to exterior

Are you a code inspector? Why do you need a source.

If there is a static pressure drop (for any reason, length or otherwise) there is a problem.

There is a thing called GOOGLE you may be interested in too!

I do have Code certs but no, this isn't a code inspection. I just don't like to to preface a statement to a client with "I think". If I'm going to say something I like to be right or just say "I dont know, I recommend consulting with expert etc.
Cameron is a really smart guy, I've read his comments before on this forum, he's just the sensitive type I guess, gotta be careful how you respond. I'm glad he lives in Peoria though. Thanks Cam!

That would be the first time I've been considered sensitive, I gotta tell my wife!  ;D

You can't go wrong calling that one out, I don't imagine their clothes dried very quick with that setup.

The matter what you do you still have to say "I don't know", because they are going to put a new dryer in (at some point in time) and different dryers have different capacities.

If you "want to know", you must get the manufacturers static pressure specifications and go to a source of duct design(SMACNA) and calculate the length of duct and it's friction loss as well as the equivalent straight pipe length of the 90? fittings and add that into the equation.

The other information concerning code specs is basically a "rule of thumb". It does not actually determine a deficiency. This is a lot of work on information that is not readily  available to have a real answer.

my uncle, a plumber, always told me "4 90's make a plug"  ;D

Close...