Understanding How Your Furnace Works

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Furnace Services in Northridge, CA

There’s nothing like the warmth your furnace pushes out when the weather cools down. To keep it running well, it’s important to understand at least the basics of how your furnace works. Here’s the preliminary information you should know, and how to keep your unit running efficiently all winter long.

Circulating Air

The first thing you need to know about your furnace is that its primary job is to circulate air. Without this air moving through your system, there’s no way for the furnace to heat your home. The circulating fan is the primary driver of this airflow, drawing air in and then pushing it back out.

The process starts when the circulating fan draws air in through the return air vent. This air passes through the furnace filter to remove most of the airborne particles that can clog up your unit.

From there, it’s heated in the actual furnace unit. After the air is heated, it’s then pushed back out through the ducts to the various parts of your home.

Any restrictions to that airflow inhibit your unit’s ability to do its job. These restrictions happen at the air filter when it gets clogged but can also happen internally in your unit and around your home.

Heating Air

Most forced-air furnaces burn fuel, either natural gas or kerosene, to create the heat needed. However, the air that flows back into your home doesn’t flow through the burn chamber. Rather, there’s draft air that allows the burn to happen, but the heating happens at the heat exchanger.

The exhaust gasses the burn chamber produces as the fuel burns are extremely hot. Before it vents outside, it moves through a heat exchanger. This is a series of metal tubes that have air circulating through them. As this happens, the heat transfers to the air, cooling the exhaust before it vents from your home. In high-efficiency models, you may have two separate heat exchangers to capture more heat and transfer it into your home.

Problems with heating can occur when there’s not enough airflow, but also if there’s a problem with your thermostat. The thermostat controls when to signal the unit to start and when to stop. If your thermostat is old, or the batteries are dying, it may not send the signals properly. Heating issues can also occur if there’s an issue with your burner, the fuel supply or control, or the ignition system.

The Importance of Size

Making sure you have the right size unit ensures your home heats effectively, without putting undue stress on the unit or wasting energy. Size is typically measured in BTUs, which is simply a measure of how much heat it produces. More BTUs equals more heat produced every hour.

A larger unit might be advantageous, being it produces more heat at once. However, when your unit is oversized for your space, it causes it to heat too quickly, shutting down the unit to prevent overheating. This leaves your space still feeling cool, which translates into more run cycles. This uses more energy and causes substantial wear on your unit due to the continuous starting and stopping cycles.

Likewise, too small of a unit means it never raises the temperature of your space to a comfortable level. Your unit will continually run, driving up your utility costs, and causing excessive wear on your unit.

Keeping Your Furnace Running Efficiently

To get the most from your unit, there are some actions you need to take to keep it running efficiently. The first step is to change your air filters regularly, usually about every three months for the common 1- and 2-inch filter. Next, check to make sure all your output vents have at least a 2-inch clearance around and above them to allow for proper airflow.

Finally, get professional annual maintenance for your unit every year. During the maintenance, a technician will clean the areas that may cause airflow restrictions, including the heat exchanger and circulating fan. They’ll tighten all the mounting bolts and check electrical connections to reduce strain from excessive vibration. They’ll also run the system through a heating cycle to ensure each component works properly, and that your unit produces the right amount of heat.

People around Northridge have turned to Kahn Air Conditioning to keep them comfortable since 1961. Our team of NATE-certified technicians offers heating and air conditioning installation, maintenance, and repair along with indoor air quality solutions. Call to schedule your furnace repair or maintenance with one of our expert technicians today.