The furnace is a device that generates heat to warm an entire building. This is typically achieved by pushing warmed air through ductwork and into connected rooms via a vent. The heat is produced by the burning of fuels, such as propane, natural gas, coal, oil, and others. There are many furnaces on the market and they have their own unique advantages and disadvantages to consider. Making a choice can be hard if you don’t understand some basic information about furnaces. In this blog, we will get you up to speed on furnaces to help you make informed decisions.

How Does a Furnace Work?

We covered this briefly in our introduction, but this is a deep topic and it merits a more detailed description here. The furnace can be powered by the fuel types mentioned earlier or it could be an electrically powered unit. The distinctions may seem mundane, but in reality the choice of fuel that you choose to use can have a dramatic impact on your home. The first thing to consider is the cost of the fuel, which will determine the furnace efficiency and the running costs.

There are different types of furnaces (more on this later) and they all work on similar principles. The furnace heats the incoming air to a higher temperature and then it circulates this treated air throughout your home with a blower (fan) unit. As the warm air enters a space, it heats up the objects in that area too, including carpets, rugs, soft furnishings, drapes and others. Most furnaces use natural gas or oil, but many modern units use electricity for power. Even if you don’t have an electric furnace, it will have electric components such as the blower unit and igniter.

The furnace may have different features depending on the specific model and these can be extremely useful. A prime example would be dampers that are designed to heat certain specific areas of the home. This will deliver treated air to certain rooms via the ductwork where heat is needed to improve energy efficiency. If they have access to natural gas, many homeowners prefer it to power their furnaces because it offers high performance at a reasonable price.

4 Key Furnace Components Explained

A furnace is an important part of your heating and cooling system. It’s complex and it has electronic, electrical and mechanical components. All these parts need to work in harmony to produce the heating that your home needs. Let’s take a closer look at the four key furnace components in more detail, they are:

1.   The Thermostat

Although this is installed in an easy to access area away from the furnace, it’s an integral component in the system. Think of the thermostat as the central brain of the entire system and you start to realize it’s importance. When you call for heat, the thermostat will send a message to the furnace to come on, but this is just the tip of the iceberg. The thermostat is the unit that allows you to control the length of the heating cycle, the temperature, and when the furnace or AC system operates. Achieving more control over these aspects of home heating will allow you to boost performance and improve energy efficiency. If you only have a basic timer thermostat, consider an upgrade to a programmable or smart unit. These offer more control to improve the indoor comfort levels and save you money on your energy bills.

2.   The Gas Valve

If you have access to natural gas, it comes into your home via a gas line. The gas valve takes this incoming fuel and then feeds it into the furnace. The fuel is fed into a burner assembly where it’s mixed with fresh incoming air delivered via the blower unit fans.

3.   The Heat Exchanger

The burner creates flames, which in turn heat a metal heat exchanger. Inside this unit, the heated air is circulated through a series of tubes, and the energy is evenly transferred to the air. The heat exchanger must be regularly maintained to run efficiently or the combustion gasses cannot be removed safely. Another potential problem with a heat exchanger is cracks in the surface where heat and flames can escape. This is a common cause of house fires and the cracks are hard to spot because they seal up when the surface cools. For this reason, it’s important to get an annual checkup for your furnace before the heating season begins.

4.   The Air Handler

This is a collective term for the blower motor and the fans that push the treated air throughout your home. The fan blades spin and move the warmed or cooled air from the furnace or AC unit into the ductwork (registers) that run through your home. The air handler has a secondary function, it pulls fresh air from outside into the system for the combustion process. This is critical, the system must have good airflow to create and deliver the treated air. So, anything that impedes the airflow will make the system less efficient and more prone to failure. The main cause of low airflow is a clogged air filter and it’s very important to check, replace and clean this component regularly. It’s also important to keep the registers clear of any obstructions such as drapes, tall furniture, store boxes, and other items.

3 Different Furnace Types

Aside from the fuel choices, there are three main types of furnaces on the market. They are:

1.   A Floor Standing Furnace

This is the most popular modern furnace type and it’s often referred to as a step-down or vertical furnace. This furnace is installed in a dedicated pit that’s around 3 feet deep and there is a space around the unit of around 12 inches.

2.   A Freestanding Furnace

This furnace has a firebox, you place wood or other fuel inside and light it to create an open flame. This, in turn, heats the air in the furnace, and this treated air is then distributed throughout the home. The furnace must be efficient if you want your home to be warm and cozy when it’s cold outside.

3.   A Wall Mounted Furnace

This is an easy to maintain unit that requires no surrounding clearance, which makes it an ideal choice for a smaller home. This is a cheaper furnace to install, but it may not produce adequate heat for larger homes or businesses.

If you want to schedule essential maintenance for your furnace or you’re considering a replacement, contact your local HVAC specialist today.