‘Mrs. Jones, we want the system to run longer so the air gets dehumidified, the hot air gets returned to the system, and the air mixes in the home. Does that make sense?’

Fixing the Ductwork

In the Northeast, of the few attic systems we service, we often run into the good old short plenum box with massive lengths of flex duct feeding off it like an overgrown octopus.

In these situations, the clients’ biggest comfort complaints are about rooms furthest from the air handler/furnace. Upon investigation, we usually find flex duct runs to those rooms that are between 20 to 30 feet in length.

Our comfort consultants will say, ‘Mrs. Jones, Your comfort issues are due to poor ductwork design. You have flexible ducts that are too long. Because of this, they slow down the air.

For example, have you ever used a garden hose to water the flowers? The water stream coming out of the nozzle is pretty good. What happens to the stream when you add another length of hose to it? It’s weak, isn’t it?

This is what’s happening with your ductwork and airflow. There is more friction in the additional hose just as there is more friction in your ductwork because the air has further to travel.?

Our consultant may add, ‘To make matters worse, there is a metal ‘slinky’ that’s wrapped along the whole inner length of the flex duct that is ribbed and slows air even more. Does that make sense? We can correct this condition with ductwork modifications.’

I hope this helps in selling ductwork modifications. Remember, speaking in ‘English’ will help your clients understand the issue. Using props will reinforce what you’re trying to say.

Good luck and stay safe!

Vince DiFilippo is president of DiFilippo’s Service Co., Paoli, PA. He is a long-time member of National Comfort Institute, is active in a number of national trade associations, a speaker and panelist at several NCI Summit events, and a recipient of NCI’s 2012 Chairman’s Award.