Why does nobody talk about the 80% rule for dryer vent runs
Was reading the install manual for a Whirlpool dryer yesterday and it says the vent run should be under 80% of the max length for your duct type, which I had never heard in 9 years of doing this. Spent the afternoon checking my last few jobs and two of them were right at the limit. Do you guys actually go by the 80% thing or just keep it under the max and call it good?