The reason your dryer needs to be cleaned is because lint can collect in the lining of your dryer vent hose, like cholesterol, and create a few problems.
1) When lint collects in your dryer vent hose it will start affecting the time it takes to dry your clothes. The lint slowly begins to choke off the air supply and will make your dryer less efficient.
2) When too much lint clogs up your dryer hose two things can happen: 1) the lint will start to collect behind the tumbler where the heating element is and may catch fire or 2) the dryer itself will burn out and replacing the dryer may be necessary.
3) The main danger of too much lint collecting in your dryer vent hose is once the lint becomes solid and thick the lint can catch fire very easily.
There are a few tell tale signs that your dryer needs to be cleaned:
1) If you notice a significant change in your drying time.
2) If you check the vent outside and you can't noticeably feel the air blowing out at least 12" from the vent.
3) If you look inside the vent itself and see lots of lint starting to collect inside.
There are a few differences between vinyl and aluminum flexible hoses.
1) Aluminum hoses have a much higher temperature range than vinyl. Aluminum hoses have a temperature range of -22F to 248F whereas a vinyl hose has a temperature range of 32F - 212F.
2) Aluminum hoses do not deteriorate like that of vinyl hoses. Vinyl hoses dry rot as a result from the heat and humidity from the dryer during its cycle. Once the dry rotting sets in the hose will develop holes and lint will collect wherever the hose is. The danger of lint collecting in the area surrounding the hose is if the lint should ever catch fire the fire will spread far beyond the hose itself and very fast.
3) Aluminum hoses, unlike vinyl hoses, are fireproof. When plastic hoses dry rot, they become brittle and extremely flammable.
No, a longer dryer vent hose is not better than a shorter hose. This is a myth.
*A shorter run from the dryer to the exit is more efficient, doesn't clog up with lint as fast and costs the customer less to clean.
*The longer the run of the hose the harder the dryer has to work to push the lint out.
*It doesn't take much lint to dramatically affect the velocity of your dryer the longer the dryer hose run is. Just a little bit of lint can affect your drying time more in a longer run than a lot of lint in a shorter run.
* Every 45* elbow counts as 2.5 feet of linear pipe and for every 90* elbow counts as 5 feet of linear pipe.
To keep unwanted critters from entering your dryer vent there are products you can purchase to cover your dryer vent.
Warning!!! Do not put any mesh on the dryer vent opening as it can become a fire hazard.
No. Although the leaf blower sounds like a good idea unfortunately it doesn't always work. The dryer is basically a slightly less powerful leaf blower and if it doesn't blow it out a leaf blower wont either. If the lint has become impacted and gloms onto the pipe (like Papier-mâché) because of the humidity created by the wet clothes it won't blow off. Think of lint as plaque on your teeth- simply spraying water on it won't remove it. You need to roto-brush the lint off.
That said using a leaf blower DOES NOT remove all of the lint from your dryer vent. Be cautious of any company that performs a dryer vent cleaning with only a leaf blower and no roto-brush.