OT Dryer venting

Re: OT Dryer venting

Tim Greif - West of Chicago

I have 4 elbows and 30 feet of duct with a louver fitting at the end to keep birds and critters out. I blow it out every couple years with a leaf blower (or whenever LOML says it's taking too long to dry). It's been working fine or 30 years. Never heard of an indirect blower that's not in the air stream.

Here is what I am looking at

Mike L

https://www.amazon.com/dp/B00TUIF8LE/?coliid=I1EXDUC8NM2MF&colid=1NSH9OT4E5FF0&psc=1&ref_=lv_ov_lig_dp_it

2nd dryer blower

Mark Mandell - Gone Round In New Jersey

Saw one in a house we looked at last year. It was a 6" duct fan hooked into the line using a 6-to-4 reducer and a 4" wye in the exhaust line. Looked to be one of several Rube Goldberg installations in that particular house that included a massage tub without a GFCI circuit and a section of plastic water line that completely defeated the electrical ground!

We didn't buy the house

Correction - 20 feet of duct, not 30

Re: OT Dryer venting

Barry Irby

Dryer venting is a significant source of fires. Until a few years ago it was common practice to vent them through plastic slinky hose. Lint would accumulate and dry out. With reduced air flow the temperature would rise and find the ignition point and.... Some of the exotic fabrics we wear produce lint that burns readily. Also, as the air flow is reduced, the the dryer takes longer and longer to dry the load.

The vents now are supposed to be run in metal ducts and the only slinky hose should be a short piece behind the dryer. And IIRC the vent should not be over 25' long but that includes all of it, and each elbow is the equivalent 8' of pipe.

I did not know the booster fans existed. They might be a good addition. Check with the dryer manufacturer and local building code.

When I was building I always tried to locate the dryer on an exterior wall. On one of two occasions I switched to 6" pipe. The problem is that that drops the velocity through the pipe in half and the lint stays behind. Takes much longer to restrict the airflow, but when it does there is a lot more fuel for the fire.

Helped my son install the dryer in his new house. Found an inline filter to put behind the dryer. Easy to open and clean out. looks like a good idea. The builder set it up to vent upward into the attic. Bad idea. We set up a "drip leg" to catch the lint in the vertical. I have several of those in my rentals. Gave up on the tenants cleaning them out periodically and send the handyman once in a while.

Re: OT Dryer venting

Walta

Read the installation instructions for your make and model of dryer. It should give you the max length and number of bends allowed.

Walta

I have

Mike L

read the instructions. I know I need a duct blower to help push the air out. My question is simple

Does anyone have experience with the pressure activated fans or the current activated fans? If so which one is better?

Re: I have

Mark Mandell - Gone Round In New Jersey

Used sail-switched and direct wired relays on HVAC ductwork helper fans. I prefer the hard wired relay.

No experience with dryer vents, however.

Thanks I wonder if they would work on a

Mike L

dryer vent. I want something to turn the fan on and off with out a hard switch.

Re:Connection

Mark Mandell - Gone Round In New Jersey

You'll have to install a relay either in the dryer itself or a current sensor either a) at the outlet or b) in the service panel.

[A sail switch is likely to get jammed with lint.]

Either way, this ain't a DIY situation. Licensed $$parky is required.

Thanks

Mike L

I looked into the switches themselves and figured it would not work so well. The fan I linked above has a built in pressure switch to turn it on and off. Looks like I will be installing sooner then latter after messing with the duct under the house again today.

Mike

Re: Thanks

Tony - Memphis

Just an FYI... I had a pressure switch on the plenum of my AC to control a boost fan. It worked great fora few years. Then, when it was cold, the switch would get stuck on and take a long time after the AC fan stopped to turn off. I insulated it and such, but it still wouldn't work. So, I built my own current sensor using an Arduino and a relay. Sears used to sell something similar - I have one to control a light that shows when the dust collector is running. I believe there are similar items on Amazon. That would be a DYI project for sure.

'Nother story....in my last apartment, the dryer duct went up into the attic, then about 20' to the outside wall. Well, all that hot air created condensation and the line was tiled back toward the dryer. So, the water would collect in the soft accordion style hook up line behind the dryer and block it!

The line was plugged solid for almost a foot

Mike L

I went and cleaned it all out, so it is working right now. I will install the blower and current switch when I get back from Long Island.