Proper Grills To Maximize Airflow

HVAC grills can be found in many different places throughout your house: on the ceilings, walls or floors, depending on the age and design of your home. Not to be confused with the type of “grills” where you make your tasty burgers and shish kebabs, these grills (sometimes called grilles if we’re being fancy) that we’re talking about are vents that pull air out of a room back to the central heating or cooling system.

Getting the right grills can have an effect on the proper heating and cooling of your home, as well as helping you manage excessive energy costs. It can also factor into excessive noise, low air volume, filter efficiency and room-to-room pressure imbalance  as well as temperature differences.

Grills come in so many shapes, sizes, colors, designs and materials, it can make a little thing like choosing a grill feel like you’re picking the best pediatrician for your kids. We want to give you the information you need so that you can choose the best grill for your home. And we want to take out all the mystery and hype to make it as simple as possible.

Here’s basically all you need to know about choosing the right grill: It’s all about maximizing airflow.

That’s it. Plain and simple. Since the grill’s entire purpose is to draw in air and bring it back to your central HVAC system for heating, cooling or conditioning then all you really need to concern yourself with is finding the grill that allows for the maximum amount of air movement.

The “Free Area”

In the HVAC business we use a term called Free Area to determine how well air can flow through a given surface. Let’s say your grill is 12” x 8.” It’s got a total surface area of 96 inches. But when you account for the border, the louvers and other design that covers the surface area, you get a much smaller area available for airflow. The lower the Free Area, the worse your airflow. 75% is typically the amount of Free Area we want to get from a good grill.

High flow return grills

If you don’t want to stress about it and you just want the best grill for your home, get a high flow return grill. The high flow return grill, also known as the fixed bar return grill is basic and simply designed but it definitely gets the job done. They’re the most aerodynamic of return grills and they tend to have the highest Free Area.

Other designs and materials

If you have a certain design theme in your home or an aesthetic you’re going for where the basic high flow return grills don’t work, then keep a couple things in mind as you look for different designs or materials in your grills.

Airflow is always the most aspect of a grill, so don’t sacrifice design for good airflow. If your grills don’t have enough airflow you could end up with all your hot air at the ceiling and your cold air at the floor level, making for an uncomfortable home with irregular temperatures.

As for materials, metal tends to be the best because the strength of metal allows for the louvers and other design features of the grill to be as thin as possible, allowing for maximum airflow. In wood grills, which have the lowest airflow, the additional thickness of the material creates a lower Free Area. Same goes for plastic, although plastic is slightly better than wood.

Grills don’t need to be a painstaking decision for your home. All you want from your grills is the best airflow possible. Just remember that and you’ll be good to go. For more info about your grills or your HVAC system, get our free guide here.