Getting to Know the Variable Displacement Damper

The Yoder Smokers YS640s achieves unmatched versatility by delivering multiple setup options allowing you to smoke, bake, roast, and grill over an open flame. One of the YS640s's unique features is the Variable Displacement Damper (VDD).

To put it simply, the VDD manages the airflow that delivers heat to support the various cooking methods. Today we’re going to talk about what that means and how it’s done.

How Does It Work? 

Essentially, the VDD acts as a dam that air can’t pass through, so the air has to find another way around.

With the damper in, the path of least resistance for that air is up to and then around the heat diffuser. If the damper is pulled all the way out, the air is free to pass all the way to the end of the diffuser, up the far wall and out through the chimney.

Moving the damper in changes the airflow and creates resistance, moving heat toward the center of the cooker and evening out the temperature in the cooking chamber.

The closer you move the airflow and heat to your food, the more effect it has on your cook. In short, the damper helps fine-tune your cook by giving you extra control over the airflow.

The Yoder Smokers Variable Displacement Damper in the fully open position.

The Yoder Smokers Variable Displacement Damper pushed in 6 inches.

The Experiment

In order to see the difference the VDD makes, we did a little experiment. We put two spatchcocked chickens of the same weight on the YS640s with the heat diffuser installed and standard YS grill grates in place.

We cooked both of them on the top shelf at 350 degrees using the same bag of BBQr’s Delight Contest Mix pellets. We pulled both chickens off at an internal temperature of 160 degrees. The only variable between the two chickens was we cooked one with the damper all the way out and one with the damper positioned 6 inches in.

The results: With the damper out, we ended up with a well-cooked chicken with even temperatures throughout in just under three hours. With the damper pushed in, we ended up with the same well-cooked chicken, but we did it in two hours rather than almost three. 

What It Means

While the temperature inside the cooking chamber did not change much at all, we were able to get the same results and shave off an hour of cook time just by moving the damper in a mere six inches.

By altering the airflow forward even that small amount, we focused the heat in the cooking chamber and moved more air over our food, maximizing the efficiency of our grill. 

The next time you use your YS640s, fine-tune your cook by moving the the Variable Displacement Damper 6 inches in.