AskCodeMan

Codeman:

Common sense dictates that a clothes dryer duct should not be terminated adjacent to an air conditioner condenser unit. Does the building code proscribe this installation?

Thanks,

Aaron

Aaron,

The codes, specifically the 2006 IRC and IMC (International Residential and Mechanical codes), do not address the location of the clothes dryer duct termination and discharge location as it relates to the location of other equipment, only as the clothes dryer exhaust termination relates to the building, specifically building openings.

It must be remembered that building codes are not written as a guide to good/better/best construction practices, but as "minimum" standards *which must be met*. Also remember that codes do not address, and are not intended to have to address, basic construction practices or common sense, to do so would create a code which would be unwieldy in size and unusable in practice.

The following is from the 2006 IRC. (underlining and bold are mine)
- 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.

That means not within 3 feet of any door, window, soffit vents, other exhaust termination or intake air inlet.

I have reviewed several different manufacturers' installation instructions and no reference is included in them regarding limitations on the location of the clothes dryer exhaust termination relating to the location of other equipment.

I have e-mailed one of the manufacturers for clarification on this issue and will add to my answer when I receive the reply from them.

Codeman

Aaron,

This is the e-mail response I received from GE regarding the location of the dryer exhaust vent discharge in relation to an air conditioning condenser unit:

Hello Mr. Peck,

Thank you for visiting our GE website. I will be glad to assist you today.

There is no minimum distance noted in the installation instructions regarding the dryer exhaust termination next to an air conditioning unit.

I hope this information is helpful. Please don't hesitate to contact us whenever you need assistance. Have a nice day, Mr. Peck.

Best Regards,
Sharon
GE Internet Response Team

Thus, it falls back to "basic construction knowledge" and "common sense", neither of which is addressed by the codes (it is "presumed" that anyone doing construction work will have *at least* "basic construction knowledge" and use "common sense".

The use of basic construction knowledge and common sense is, unfortunately, not always the case, as evidenced by the many outright stupid and silly things we find in construction - many of which are life safety issues.

Codeman

Some of the dryer duct exhaust may detrimental to the ac coil, some fabric softener or chemical may cause the aluminum coil to breakdown.

Richard,

Thank you for the additional information regarding what may be in the exhaust air from the clothes dryer.

There certainly are chemicals used in detergents, water softeners, bleaches, etc., which you do not want to exhaust onto the air conditioner condenser unit coils.

Also, to answer this, I reversed the question to ask (from the air conditioner point of view): "What is not allowed to discharge onto the air conditioner condenser unit, how far from clothes dryer exhausts is the condenser unit required to be?"

So far, the only reference to the "What is not allowed to discharge onto the air conditioner condenser unit" part of that question I found were in Carrier 'Owner's Information Manual' where it states:
- Do Not Cover or Block Outdoor Unit
- - The outdoor unit needs unrestricted airflow. Do not cover it or place items on or next to it. Do not allow grass clippings, leaves, or other debris to accumulate on the sides or top of the unit. And, maintain a 12” (304.8 mm) minimum clearance between the outdoor unit and tall grass, vines, shrubs, etc.

"Clothes dryer lint" should certainly fall into the category of "Do not allow grass clippings, leaves, or other debris to accumulate on the sides or top of the unit."

Codeman