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Understanding Furnace Air Flow Configuration

A strong, well-working furnace is a necessity when it comes to surviving a long cold Minnesota winter in comfort.

Yet not all homes are always able to accommodate a standard furnace design – especially ones that don’t have a basement.

Fortunately, that problem can be worked around by selecting a furnace with a different air flow configuration.

This article discusses the two most common furnace air flow configurations.

Her’s what you need to know.

1. Upflow Configuration

You can probably guess from its name that a furnace with an upflow configuration is designed to send its heated air out through the furnace’s top side.

In fact, the majority of homes have upflow furnaces.

Part of the reason for this is that duct systems are generally built to extend upward from the furnace, which is housed at the bottom level of the home – in other words, the basement.

There is a further distinction that can be made within the realm of upflow furnaces. This has to do primarily with the size of the furnace.

Full-size units are commonly known as highboys, and are the standard choice, if there is adequate clearance to fit one inside the basement.

For those with a basement with an especially low clearance, it may be necessary to install a lowboy furnace instead.

These are simply more squat than highboys, and in all other regards, the two varieties operate in much the same way.

2. Downflow Configuration

Downflow furnaces represent a significant difference in terms of their design compared to upflow furnaces.

As you can likely deduce, a down flow furnace is designed to deliver its air into the duct system through its bottom side.

This is not necessarily a desirable thing since hot air has a natural tendency to rise, but in homes that lack a basement, or whose basement is simply too small to house an upflow furnace, a downflow unit may be the best choice.

In this case, the furnace is generally housed in the attic and is integrated into the duct system from above.


If you’re interested in seeing whether an upflow or downflow furnace is right for you, want some advice on improving your heating, want a new furnace, or just need a furnace repair, then why not Contact Us today at (651) 294-7798?

We cover Blaine, Bloomington, Brooklyn Park, Eagan, Edina, Hastings, Maplewood, Minneapolis, Minnetonka, Roseville, North Saint Paul, Saint Paul, Saint Paul Park, South Saint Paul, Stillwater, West Lakeland, West Saint Paul, White Bear Lake, Woodbury, and many more locations.

Can’t find your town listed? Contact us at (651) 294-7798 to tell us where you live, so we can help you get the right furnace to suit your home and your family needs.


Schedule a HVAC repair anywhere in the Minneapolis or St. Paul area today by calling (651) 294-7798 or by requesting an estimate online.


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