This could cause the lint ot build up and cause blockage as well. Third, using PVC to vent a dryer is a violation according to most residential building codes.
Ideally you want rigid metal duct. Having less change of crimping and bending means less chance of lint buildup, which means less chance of fire hazard.
Dryer vents should either be solid steel vent pipe or solid aluminum vent pipe. Do not use plastic vent pipe! its a safety and fire hazard. Aluminum foil vent pipes are almost as bad as plastic but still safer being less of a fire hazard...
Never ever use a plastic duct to vent your dryer! In fact, it is against many local building codes to use a plastic duct on a dryer. Modern dryer heating elements are very powerful and can ignite the lint accumulated inside the plastic duct and the dryer, starting a house fire.
Although dirty, this break allows heat and moisture to escape and limits your immediate risk of a dryer fire. PVC piping will not do this which leads to water pooling and severe clogs. These clogs will cause your dryer to overheat and become a potential hazard.
M1502.
Exhaust ducts shall be constructed of minimum 0.016-inch-thick (0.4 mm) rigid metal ducts, having smooth interior surfaces, with joints running in the direction of air flow. Exhaust ducts shall not be connected with sheet-metal screws or fastening means which extend into the duct.
All dryer ducting must be a minimum of 4" in diameter.
It's also resistant to corrosion, making it the perfect material for transporting harmful gases and fumes. Unfortunately, due to its temperature limitations, PVC duct may not be the right material for HVAC systems, and it's not designed to withstand pressurized liquids.
The dryer exhaust duct should vent directly to the exterior in a short, straight line, via a smooth, rigid metal duct. Figure 2. At the outlet of the dryer exhaust duct, install a hooded vent with a louvered damper.
conditions should be at least 1,200 FPM (feet per minute) to keep lint moving through the vent. (In a 4" (102 mm) diameter pipe, this requires at least 105 CFM of air flow.) Back pressure should be measured with an empty dryer, a clean lint screen and with the dryer operating in the Air Only cycle (no heat).
For clothes dryer venting, a 4-inch, rigid aluminum or galvanized steel duct pipe is a better option.
Be sure to keep 90-degree bends to a minimum. Every 90-degree bend is the equivalent of ten feet of vent run. Never install a dryer vent which has a bend greater than 90 degrees. Sharp bends restrict airflow and will lead to excessive lint buildup.
A rigid metal duct tends to be the best type of dryer vent hose. This tube provides a straight, direct line to the outside. Its inner wall is smooth, and it lacks the ribs found in flexible dryer hoses.
For example, flexi duct can be used for a bathroom fan's system, but is prohibited in dryer ventilation systems, and PVC and PVC coated aluminum can be used for bathroom fan ducts, but is very dangerous to use for dryers.
Fire Safety: Speaking of fire risk, a hard pipe is also safer than flexible accordion piping. The ridges and creases in flexible piping can trap lint and other debris, which can quickly accumulate and become a fire hazard.
National (international) plumbing codes identify vent pipe size, length above the roof, flashing and caps. But does not specify material. PVC, ABS and galvanized have all been used.
Where subject to physical damage, except as permitted in 352.10(K). Where subject to ambient temperatures in excess of 50°C (122°F) unless listed otherwise. In theaters and similar locations, except as provided in 518.4 and 520.5. PVC conduit smaller than metric designator 16 (trade size 1/2) shall not be used.
Per ASTM E84, PVC does not meet the 25/50 flame and smoke requirement for plenum applications as defined by the model mechanical codes in the U.S.
All PVC pipe and fittings have a max operating temp of 140 degrees Fahrenheit. Now think about how hot your dryer gets. All that hot air and moisture running through the pipe for years is bound to do some damage. This may cause the plastic to go soft and cause some blockage in the long run.
M1502.
5 code, the construction of a dryer duct has to be a minimum of 0.4 mm thick with a smooth interior. This means ribbed vents are no longer being used. Additionally, all duct joints must point in the direction of airflow.
Materials Approved for Dryer Vent Construction
Rigid Metal Ducting: Rigid metal ducting, such as aluminum or galvanized steel, is widely considered the gold standard for dryer vent systems. These materials are non-combustible and can withstand high temperatures, reducing the risk of fires.
504 requires a dryer exhaust to be vented to the outside. This has been in the code for many years. There is an exception for a ventless dryer but the dryer has to be listed and labeled. Also the room where the listed and labeled dryer is installed shall have a 70 cfm exhaust fan and a floor drain.
Some places or building codes may not allow indoor dryer vents due to safety concerns, so check your local rules.
Aluminum Foil Duct
The most common type of duct material, due to its low cost and flexibility. It's held in place with dryer clamps, and usually isn't allowed to be longer than 8 feet.