Furnace Repair Brampton

Where Do Furnaces Get Air From?

where do furnaces get air from

Winter is quickly approaching. You want to ensure that your home is safe and comfortable when the frigid temperatures arrive. One of the essential elements in achieving this goal lies within your furnace, which is having a reliable air source. But do you know where it gets that air from?

Understanding how furnaces get air can help determine which option works best for your home and budget. Keep reading to find out more about how furnaces get their air!

Direct Vent Furnaces

Direct vent furnaces have a sealed combustion chamber, pulling outside air directly to the chamber through an exterior vent. The furnace ignites the air, and combustion gases go directly outside without mixing with indoor air. The heat exchanger warms the air, and the blower motor distributes warm air throughout your home through a ductwork system. These furnaces often use PVC pipes to bring in air through one vent and exhaust fumes back outside through another vent.

Benefits of Direct Vent Furnaces

  • High Efficiency – Direct vent furnaces are highly efficient as they draw in air from outside, eliminating wasted energy and heat loss. They have an efficiency rating of between 80 to 98 percent.
  • Safe – They are designed to ensure the complete isolation of combustion gases from the home’s interior air, which makes them safe and reduces the risk of carbon monoxide poisoning.
  • Environment-Friendly – Direct vent furnaces are environmentally friendly as they emit fewer greenhouse gas emissions, making them a more sustainable energy option.
  • Aesthetically Pleasing – They are located outside your home, which reduces noise and gives your home a cleaner, uncluttered look.

Induced Draft Furnaces

Induced draft furnaces use a blower motor to draw air from the outside into a heat exchanger. As the air passes through the heat exchanger, it gets heated and then moves into your home through a ductwork system. The furnace exhausts the combustion gases outside through a flue, which improves air quality inside the house. These exhaust fumes go outside through a flue, which completes the combustion cycle.

Benefits of Induced Draft Furnaces

  • Efficiency – These furnaces are more efficient than natural draft furnaces as they use a blower motor to regulate airflow, ensuring that air is correctly distributed throughout the home.
  • Cost-effective – Induced draft furnaces can be cost-effective as they are more efficient than natural draft furnaces and rely on a blower motor to circulate air, reducing energy bills.
  • Safety – Induced draft furnaces are a safer option than natural draft furnaces as they use a sealed combustion chamber, which reduces the risk of carbon monoxide poisoning.
  • Environment-Friendly – Compared to natural draft furnaces, induced draft furnaces are more environmentally friendly as they emit fewer greenhouse gas emissions during combustion.

Natural Draft Furnaces

Natural draft furnaces rely on natural heat-rising principles to pull air up a flue, creating a draft that draws combustion gases from the furnace and expels them outside. These furnaces rely on natural airflow to supply air, making them less efficient than other furnace types. As hot air rises, it pulls air from an open combustion chamber into the furnace. The heat exchanger then heats the air and distributes it through a ductwork system throughout the home.

Benefits of Natural Draft Furnaces

  • Affordable – Natural draft furnaces are relatively inexpensive to purchase and install, making them an ideal option for individuals on a tight budget.
  • Low Maintenance – These furnaces require less maintenance than other furnace types since they don’t have mechanical parts or a blower motor.
  • Durability – Natural draft furnaces have a long lifespan, which means they can last many years with proper care and maintenance.

Importance of Proper Air Supply

The proper air supply is essential for your furnace’s efficient and safe operation. Without an adequate air supply, your furnace can overheat, underperform, and result in more expensive repairs or replacements.

How Proper Air Supply Affects Furnace Efficiency and Overall Functionality

A furnace’s air supply is critical to its overall functionality and efficiency. The amount of air supplied affects the quality of combustion, the amount of heat produced, and the level of maintenance required. Furnaces that do not receive the correct air supply can have issues such as:

  • Reduced Efficiency – Failing to receive the proper air supply will reduce a furnace’s efficiency, increasing energy bills and reducing home comfort.
  • Uneven Heating – Inconsistent air supply can lead to uneven heating throughout the home.
  • Overheating – When a furnace doesn’t receive enough air, it can overheat and require costly repairs.
  • Short Cycling – A lack of airflow can cause a furnace to short cycle, which will increase energy usage and costs.

Recommendation to have an expert assess the furnace to ensure the correct air supply

It’s essential to have an expert assess your furnace to ensure it receives the correct air supply. A professional furnace technician can inspect your furnace and identify any issues preventing it from achieving the correct air supply.

Regular furnace maintenance by a professional technician can ensure that your furnace operates efficiently, reducing energy costs and preventing costly repairs. Moreover, a professional inspection will ensure that the air intake and exhaust are not blocked, and the furnace operates within the manufacturer’s recommendations.


In conclusion, various furnace types are available, and each has different air supply sources. Natural draft furnaces rely on natural airflow for air supply, while direct vent and induced draft furnaces use mechanical parts like blower motors to circulate the air.

All furnace types need to receive adequate air for efficient operation, so it’s vital to ensure your furnace is serviced regularly and that there are no air intake or exhaust blockages. Having the right air supply for your furnace can provide proper heating throughout your home and potentially reduce energy costs.