dryer vent

[truevalue]

hi

do you know when you know you read something in your book, then later on you need this info you go back and can't remember under what topic was it? dryer vent is maxed to a certain lenth in ducting hose and with elbow reduction if it's 45 or 90 degree elbow the max span on duct changes to a lesser lenght. 1. any info on that? 2. what is the standard for the hight of the outside dryervent , the one I have is against the floor. witch would make it even with the back of the dryer vent exit. can't tell if the hose going up the cieling and at the out side wall going down to the floor and out of the house, if that the case is that ok.

[davidlord]

This is from the International Residential Code.

SECTION M1502

CLOTHES DRYER EXHAUST

M1502.1 General.

Dryer exhaust systems shall be independent of all other systems, and shall convey the moisture to the outdoors.

Exception: This section shall not apply to listed and labeled condensing (ductless) clothes dryers.

M1502.2 Duct termination.

Exhaust ducts shall terminate on the outside of the building. Exhaust duct terminations shall be in accordance with the dryer manufacturer’s installation instructions. Exhaust ducts shall terminate not less than 3 feet (914 mm) in any direction from openings into buildings. Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.

M1502.3 Duct size.

The diameter of the exhaust duct shall be as required by the clothes dryer’s listing and the manufacturer’s installation instructions.

M1502.4 Transition ducts.

Transition ducts shall not be concealed within construction. Flexible transition ducts used to connect the dryer to the exhaust duct system shall be limited to single lengths, not to exceed 8 feet (2438 mm) and shall be listed and labeled in accordance with UL 2158A.

M1502.5 Duct construction.

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.

M1502.6 Duct length.

The maximum length of a clothes dryer exhaust duct shall not exceed 25 feet (7620 mm) from the dryer location to the wall or roof termination. The maximum length of the duct shall be reduced 2.5 feet (762 mm) for each 45-degree (0.8 rad) bend and 5 feet (1524 mm) for each 90-degree (1.6 rad) bend. The maximum length of the exhaust duct does not include the transition duct.

Exceptions:

1. Where the make and model of the clothes dryer to be installed is known and the manufacturer’s installation instructions for the dryer are provided to the building official, the maximum length of the exhaust duct, including any transition duct, shall be permitted to be in accordance with the dryer manufacturer’s installation instructions.

2. Where large-radius 45-degree (0.8 rad) and 90-degree (1.6 rad) bends are installed, determination of the equivalent length of clothes dryer exhaust duct for each bend by engineering calculation in accordance with the ASHRAE Fundamentals Handbook shall be permitted.

[Mike Lamb]

Originally posted by truevalue

hi

do you know when you know you read something in your book, then later on you need this info you go back and can't remember under what topic was it? dryer vent is maxed to a certain lenth in ducting hose and with elbow reduction if it's 45 or 90 degree elbow the max span on duct changes to a lesser lenght. 1. any info on that? 2. what is the standard for the hight of the outside dryervent , the one I have is against the floor. witch would make it even with the back of the dryer vent exit. can't tell if the hose going up the cieling and at the out side wall going down to the floor and out of the house, if that the case is that ok.

I have trouble understanding your English but my Maytag says the the exterior exhaust hood should be a 12" min. above the ground or any obstuction, such as flowers, rocks, snow line, etc.

If you get the make and model of your machine you could probably get the installation instructions over the internet. I have found that the IRC requirements are often about twice as strict as the manufacturer re: duct lengths which is probably a good thing.

[truevalue]

hi

thanx guys for the info. was very useful. I think the make of the dryer is maytag. I appreciate the help.[:-thumbu]