What Is the Purpose of a Furnace?

Furnaces are used in a variety of industrial manufacturing processes, such as annealing, melting, tempering, and carburizing. They also come in many designs to fit different purposes.

Your home’s furnace uses ductwork to push warm, filtered air throughout your house. It consists of six main parts: the thermostat, gas valve, blower, heat exchanger, burner, and air ducts.


A thermostat controls when the furnace turns on and off. It does this based on the temperature setting it receives from the homeowner. It can also be programmable for different settings throughout the day depending on your schedule and needs.

When the thermostat sends a signal to turn on the furnace, a gas valve opens. It then takes gas fuel from the meter into a burner component which mixes with air that has been drawn into the system through ducts by the blower fan. The flames from the burner heat a metal heat exchanger through loops of tubes, turning it into warm air that is then blown out into the ducts by the blower.

While this happens, the ducts draw back in cold air from return ducts which helps to maintain a comfortable indoor temperature. The process repeats until the desired thermostat setting is reached and then the system shuts off. Any waste combustible gasses from the combustion process are vented through a flue or vent pipes which are typically run through the roof or side of the house in a chimney-like fashion.

When the 'Auto' function on the thermostat is set to run, it will start the blower when it receives a signal from the thermostat that the room temperature is getting too low. This feature helps to reduce energy usage as it only operates when the furnace is needed. It also allows the blower to run less often, helping to keep your home's air filters clean. When this feature is off, the blower will operate as normal and run for about a half minute after the furnace turns on before it is turned off again.


The condenser is a set of tubes that receive the high-pressure gas from the compressor and converts it to a liquid. This happens by using the principle that heat will always move from a warmer to a cooler substance. Air passing over the condenser coils carries away the heat and the gas condenses into a liquid, which can then be pumped back into the furnace or stored for future use. The condenser also serves to reduce the amount of flue gasses being vented into the atmosphere. This is a major benefit of a furnace that uses R-12 rather than the less efficient R-134a refrigerant.

A furnace that has a traditional single heat exchanger loses a lot of the energy it uses in the form of water vapor as it vents out through the chimney. This can add up to a significant loss of efficiency. To counter this, furnaces that use a second heat exchanger to extract additional heat from the water vapor in the exhaust can be 10%-20% more energy-efficient than other types of furnaces.

Furnaces can come in a wide variety of shapes and sizes depending on the type of work they do. Residential furnaces are designed to warm up the air and then pump it through a duct system that distributes that warm air to other parts of the house or business. They are often paired with an air conditioner or other cooling system to keep the indoor temperature as comfortable as possible throughout the year.

Industrial furnaces are designed for more specialized jobs such as annealing, melting, tempering and carburizing metals. They can be powered by various fuel sources including fossil fuels, natural gas or oil. They can have either single or multiple heat exchangers and they can be fueled by liquids such as steam, hydrocarbons, water vapor or other substances. They can also be powered by direct or indirect contact with the workpiece.


The blower motor in a furnace (also known as the fan) moves conditioned air through your home, making sure it gets to all the rooms and spaces. It is one of the only components in your HVAC system that runs year-round.

Once warm air is created by your furnace through its heat exchanger, the blower fan moves it through ductwork that distributes the heated air throughout your home. The ductwork can be made of sheet metal or flexible plastic “flex” ducting, and it may be insulated or not. The blower fan pulls air from outside, passes it through a filter to remove dust and dirt, and then into the plenum or blower chamber.

There are many different types of blower motors, but the most common ones are direct drive. The motor’s spindle connects directly to the blower wheel, so there is no need for a fan belt as in older models of furnaces. Other types of blower motors include belt-drive and variable speed. The blower motor can also have a single or two-stage gas valve.

A single-stage blower can only run at full power, while a two-stage blower can switch between high and low settings. This allows the blower to match your system’s heating capacity to its output, which can save you energy and money.

It is important to note that if you leave your blower on nonstop, it can put more stress on the fan and cause it to wear out faster than necessary. It is also possible to overheat your system, so it is important to use it in accordance with the manufacturer’s guidelines. Likewise, it is important to change your furnace filter often. A clogged filter will force the blower to work harder and consume more energy, and it will be hard for your system to distribute conditioned air evenly throughout your home.


The burner is the component of a furnace where air mixes with fuel to create heat. That heat travels across the network of pipes or ductwork that distributes it throughout your home. The fuel source could be gas, oil, or propane. The burner might include a pre-mixer to help ensure efficient combustion.

The heating cycle begins when your thermostat signals the heater to turn on by “calling for heat.” At this point, the fuel valve opens delivering fuel to the burners. An air intake brings in outside air to mix with the fuel. Then the pilot light ignites the mixture to create a flame that heats the heat exchanger. The warmed air is blown by the blower into supply ducts (those louvered openings in walls or floors where filtered, warm air travels into your home) and distributed to other rooms via vents.

Historically, natural draft (atmospheric burner) gas furnaces were built of cast-iron or riveted-steel heat exchangers in a shell of brick, masonry, or steel. The heated metal surfaces of the heat exchanger transferred their warmth into air circulating through a series of large, upwardly pitched pipes made from wood or metal. This forced-air system worked because warm air rises.

Older models also used a stack, or chimney, to disperse the flue gases produced by the heating process. This was necessary for safety reasons because these gases contain carbon dioxide and water vapor. In newer gas furnaces, these emissions are treated and dispersed through an air scrubbing process before they’re released into the atmosphere.

Heat Exchanger

The unsung hero of your furnace, a heat exchanger helps gather hot combustion gases from the burners and funnel them into air ducts that spread warm air throughout the home. The heat exchanger also keeps toxic fumes from escaping into the living spaces of the house, safeguarding your family’s health and safety. However, cracks in the heat exchanger often cause carbon monoxide leaks and other problems.

The hottest flue gases in your furnace’s combustion chamber burn the inside walls of the heat exchanger, making them extremely hot. This causes the metal to expand and contract, which can wear away at its integrity and eventually crack it. Those cracks can allow toxic fumes to leak into living spaces, which could lead to CO poisoning.

Fortunately, you can prevent this by keeping your furnace clean and up to date with Furnace Repair Sandy Utah. A clogged furnace filter or other blockage can keep air from flowing freely through the heat exchanger, which can cause it to overheat and overwork itself, leading to stress cracks. Frequent on-and-off cycling also can wear the heat exchanger out sooner than it should.

Most gas furnaces have two heat exchangers: a primary and a secondary. The primary heat exchanger, which is close to the burner assembly, takes the brunt of the hottest flue gases. It can be made of aluminized steel or stainless steel. It may have a single coil or a series of tubes. The second heat exchanger usually consists of several thin, corrugated metal plates bundled together into pairs. Each pair creates a passage through which one gas can flow, and each pair is joined by brazing or welding. The plates also are cooled to prevent them from overheating. And if you're looking for a furnace repair business that will complete the job correctly the first time. 

We are Furnace Repair Sandy, Utah's most dependable furnace installation and repair company, expertly looking after our clients. Our group is passionate about heating and furnace repair; it's not just our job. We pledge to give you the best furnace repair or replacement services available. No of the hour, day, or circumstance, you can rely on us to complete the task effectively and correctly. Click here for further details @https://www.furnacerepairsandyutah.com/ 

Furnaces are used in a variety of industrial manufacturing processes, such as annealing, melting, tempering, and carburizing. They also come in many designs to fit different purposes. Your home’s furnace uses ductwork to push warm, filtered air throughout your house. It consists of six main parts: the thermostat, gas valve, blower, heat exchanger, burner, and…