Major Venting Problems

Dryer venting

Author Topic: Major Venting Problems  (Read 3626 times)


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Major Venting Problems
« on: June 25, 2018, 03:06:50 PM »
A little background. My house was built in the 1970s, with an addition made in the 1980s. The design of the addition was bad, as was the construction. When we moved in, I noticed that the dryer vent was flexible plastic. As a result, we never used the vent, planning to replace it with rigid pipe at some later date. Because of the addition, the dryer is on an inside wall, and the vent goes through the floor into the basement ceiling, then outside. The problem is with a lot of obstructions and the turns that would be needed.

The pipe will need to go through the floor, run about 32", then make a turn and drop 6". Where the joist is cut now, the turn would be about 45 degrees. I could move the cut and make it a 90. it will then run 5', make another 90, run 28", make a 45 degree turn and out. The wall behind the dryer was once an outside wall, and they bulit another wall behind it. Effectively making it six inches deep.

My questions are first, can the long radius Ell tie directly into the Dryerbox? I have just about 10" between the bottom of the sill the vent goes through, to the top of the drywall cieling. Could a semi-ridgid pipe be used for the turn and the drop? I'm thinking that I might be able to put two Ells together for the turn and drop, but I'm not sure of the exact angles. Let me know if you have any ideas or suggestions.

The amount of lint in the plastic vent was unbeliveable. I really don't know why the prior owner didn't burn the house down.

Thanks for any help.


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Re: Major Venting Problems
« Reply #1 on: July 10, 2018, 12:41:08 PM »
Super sorry for the delay in responding.  I had surgery. 
We like to say, that the LT90 works and fits in floor joists that are at least 11.5" and the flooring has two layers of plywood.  Sounds like we may miss that.  The LT90 will not fit into the hole or port of the downbox, but only needs a 3.5" long nipple and it works, but maybe not for you cause of the depth of the floor joist. 

Newer dryers are very capable of pushing 35 to 50 feet of pipe, and you have to then deduct 5 feet for each 90, assuming you are using the twisty turn ells.  Aluminum flex is prohibited from being used in concealed spaces per code, but it may offer a better means to getting around all the obstructions.  Using a dryerbox does eliminate the one ell behind the dryer in the wall. 

Am happy though that you discovered the vinyl flex and removed it. 

Feel free to call me or reply.  thanks. 
In-O-Vate Technologies, Inc
Jupiter, FL  33477