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Bert32
Nov 7, 2008, 04:27 PM
Hello,

I have a bungalow that sits low to the ground. To run a dryer vent the highest I can vent the dryer from the basement is less than 1 ft. What can I do? Is there a code for how high this needs to be?

hvac1000
Nov 7, 2008, 04:33 PM
The dryer vent needs to go outside. If to low by code due to snow load conditions you can add a elbo outside with a short piece of pipe going up and another elbo at the top to keep out the rain/snow etc.

The materials you use must meet UL-181 standards per code. NO flex plastic dryer vent allowed. Use metal pipe or flex metal pipe that meets UL-181 standards. Flex metal pipe will have a label listing the UL number.

Bert32
Nov 7, 2008, 05:47 PM
Will that not cause condensation to run down the pipe when the warm air being veniltated meets the cold air outside?

letmetellu
Nov 7, 2008, 06:16 PM
Yes it could cause some condensation but I think this could be over come if you would drill a hole in the bottom of the bottom ell this would let any moisture bleed away

mygirlsdad77
Nov 7, 2008, 06:58 PM
Gas or electric dryer?

Bert32
Nov 7, 2008, 07:25 PM
Electric dryer

hvac1000
Nov 7, 2008, 07:26 PM
Yes it possibly could cause some condensation but I think this could be over come if you would drill a hole in the bottom of the bottom ell this would let any moisture bleed away



letmetellu has it correct about the hole in the bottom of the elbow. I am getting old and forgetful. LOL Thanks letmetellu.

Many years ago on a large apartment complex job my company used "B" vent to vent the dryers just like what was mentioned above in regards to the condensation problem. This was in New York City and at the time they were enforcing the codes since I was a out of town contractor. We also had to make a welded steel cage around the "B" vents to prevent vandalism and damage from cars in the parking lot area very similar to the protection post requirements of today’s code. We also used a product called Hard Cast to wrap the vent to enhance its performance (insulate) against condensation. New York was tuff to work in. The local union halls had to be bribed or greased and the inspectors were always looking for carfare (bribes) if you know what I mean. From what I understand it is worse today.

Three years ago on a trip to New York City I had to bribe the cops at the tunnel to open up a closed lane so I could use it to get my truck passed to Long Island so I could visit an old friend. On the way back I had to stop of at Christie's Auction at Rockefeller Plaza off 49th street so I could drop off some western art that they were going to auction for me on consignment. I had to bribe the cops with a 100.00 bill so they would provide me with guarded temporary parking so I could unload the paintings and bronzes without getting my truck stolen. You could not pay me to live or work in NY. Sorry about the rants of an old man but I am still mad about it and the dryer venting problem started me thinking. LOL

BTW you can also use "B" vent to solve most of the condensation problem. The inner liner of the "B" vent helps to keep the condensation down.

mygirlsdad77
Nov 9, 2008, 05:01 PM
With electric dryer, I wouldn't really worry too much about condensation problems(wont be enough to notice) Have always used metal or platic flex with no problems, my boss has done it this way for 30+ years with never a noticeable condensation problem.

hvac1000
Nov 9, 2008, 06:24 PM
my boss has done it this way for 30+ years with never a noticable condensation problem.

Being wrong for 30 years does happen. You have to consider many different things when talking dryer vent and gas or electric is only one item.

In a load of clothes there is many pounds of water. That water is cooked out of the clothes and into the dryer vent. At some point the water/moisture falls out of suspension (kind of like a high efficiency furnace). Since the duct was going to be run outside for a foot or so with elbows when cooler weather hits it can condense and run down the pipe. Drilling a hole for it to escape is a positive solution.

Have always used metal or plastic flex with no problems

There is NO plastic flex that meets the UL-181 dryer vent standards. Now it could be that when the plastic flex caught fire from a lint fire in the dryer your boss was not around or the insurance company could not find the records of who did the work since he probably did not have a permit to start with. The concern for the safety of my customers always comes first. The codes were originally written by insurance companys to help stop there losses due mainly to fires many years ago. Today there are code panels and testing companys like UL and CSA that do there best to assure the safety of the public. The only danger left is contractors that do not know what they are doing or find it cheaper to do the work by not following the code.

mygirlsdad77
Nov 10, 2008, 06:03 PM
Correct, I was wrong about plastic flex for dryers, I let my typing fingers get ahead of my brain. Thought about it and we only use it for exhuast fans and sometimes flexable duct work, never dryers. Also correct about the outside piping. We only use termination kits for driers. Good to learn that when I do run into this, I now know to drill the hole.