Dryer venting question

I own a 4-family house in New York City. The washer and dryer (which are used by the tenants of all 4 apartments) are in the cellar which has windows which open onto a small enclosed court or airwell (approx 3x12 feet), The unattached building adjacent rises approx. 12-14 feet above the floor of this airwell.

The dryer currently vents out into this airwell and the frequent use of the dryer creates a mass of warm air that sometimes overwhelms the air conditioner in the first floor apartment immediately above.

Now the question: Would it be (A)safe and (B) practical to extend the venting up the airwell wall to a point higher than the adjacent building and aimed out over the airwell itself to allow the warm air to escape more readily? If so, what would be the required diameter of the rising pipe and should it include a section extending below the dryer's exhaust to allow lint to fall to the floor of the airwell for collection?

Thanks for your help.

 

Welcome to the forums.

I'm not quite sure how to answer your question. The one big problem is that a dryer has a limited amount of exhausting power and I'm not sure how far you can extend it.

I'll give it some thought and in the mean time others may have an idea.

 

Where the vent comes through the wall install a tee with the "run" vertical and the vent from the wall entering the side of the tee. Add ABS or PVC pipe up the preferred distance, fastening it to the wall as needed for support. Do not cap the bottom of the tee.

When the dryer first starts a small amount of the heated exhaust will spill out the bottom of the tee until the pipe warms up and then a natural draft will "pull" the exhaust upwards along with some air through the bottom of the tee. You might have to experiment a bit with narrowing down the bottom inlet of the tee for best operation. Using plastic will insulate the air column in the pipe to help create the draft.