When the time comes to replace your furnace, whether it is to improve energy efficiency and lower your utility bills, or because your existing furnace is old and broken beyond repair, trying to figure out your options can be overwhelming.

What type of furnace would work best in your home?

What space limitations do you have?

Which type of equipment will run most efficiently and save you the most money over time?

These questions may leave you feeling confused and stressed. At Cool Breeze, our Maryland HVAC installation pros consider it our goal to help you be informed and make wise decisions. Let’s take a look at your options when it comes to installing a new furnace (or an air handler if your system includes a heat pump).


You are probably used to your home appliances being installed in an upright position. This is true for almost everything, but when it comes to furnaces and air handlers, they can actually be installed both ways.

  • Vertical or upright installation can be performed in two ways: up-flow and down-flow. The flow refers to the direction of the air as it passes through the furnace or air handler. So in an upflow vertical furnace, the cold air is taken in from the bottom and the warm air is released from the top. In a down-flow furnace it’s vice versa.
  • Horizontal installation is also available for some furnace and air handler models. Horizontal units can be installed in attics, garages or basements either by placing the device on a platform or suspending it from the ceiling.

So which HVAC system should you choose? And does it matter at all whether it’s vertical or horizontal? Let’s dive into specific HVAC installation scenarios.


If you plan to have your furnace in the basement or crawl space, an up-flow furnace will be the most energy efficient for your home. These units draw in cold air at their base, and expel the heated air from the top. And because hot air rises, it makes the most sense for this unit to be in the basement. It’s also a more comfortable arrangement, as the warm air typically enters from the floor registers and warms your feet first. Because of their energy efficiency, up-flow vertical units are the most common in homes today.


In a down-flow furnace, the cold air is drawn from the top and expelled as warm air out of the bottom of the unit. A down-flow unit is generally installed in the home’s attic, and tends to be less energy efficient. In some homes, a down-flow furnace is the only option due to space constraints. The pricing of a down-flow furnace is similar to that of an up-flow furnace, however sometimes installation costs can be higher because the work tends to be done in smaller, less accessible places.


A horizontal furnace is most commonly installed in small spaces that won’t allow for a traditional vertical furnace. These units draw in cool air from one side and expel warm air from the other. Like down-flow furnaces, these units are also less energy efficient than up-flow units and are primarily used in homes with limited space that doesn’t allow a vertical installation.

Other Configurations

Less commonly used units include an up-flow/horizontal furnace, a down-flow/horizontal furnace, and a multi-position furnace. These units do basically what their names imply. Up-flow/horizontal and down-flow/horizontal furnaces can be installed horizontally, but the airflow direction in them can’t be changed. A multi-position furnace or air handler, on the other hand, can be set to process the air however the homeowner would like. These furnaces and air handlers can be installed either horizontally or vertically, and the air flow can be changed to fit the home’s needs.

Choosing a new furnace for your home can seem like a daunting task. Here at Cool Breeze, our Maryland HVAC experts would love to work with you to determine the most efficient and cost-effective HVAC installation for your home. Contact us today for a consultation or a quote!