What are the maximum number of joints a recommended in the dryer vent pipe for these electric Ge profile dryers.

Codes typically require that the dryer duct be no more than 25 feet long. It should be 2.5 feet shorter than 25 feet for every 45-degree bend and 5 feet shorter for every 90-degree bend. If the duct is more than 25 feet in length, the system requires a booster fan or a high-output dryer. Ducts should be smooth metal with a minimum diameter of 4". Flexible ducts shouldn't be used, since they collect more lint and can easily be crushed, impeding airflow and potentially starting lint fires. The ducts shouldn't have screws or connectors, which could collect lint, blocking the flow of combustion gases. Backdrafting can occur if the ducts are blocked, sending harmful carbon monoxide back into the home.