What Is A Gas Furnace?

Gas furnaces are widely used in cold countries where temperature dips down to negatives in winter months. It is actually a system that ignites gaseous products to produce heat. There are a variety of gaseous products that furnace can use for combustion. Choosing a fuel depends by and large on your location.

Furnaces are being used in homes since long. They have been run with various types pf fuel. The earliest types of modern furnaces relied on coal and wood to generate combustion. Researchers have made these hating systems more and more refined and clean in terms of operation. The modern efficient furnaces are musty run by natural gas and propane. The use of propane as a fuel in gas furnaces is gradually decreasing. Many homes are converting to gas.

How does a gas furnace work?

The gas furnace is integrated with a thermostat. The thermostat sends signal to the furnace that it needs heat when it feels that the room temperature has dropped below the comfort level. The signal is inform of low voltage electric signal which leads to opening of the valve allowing natural gas to reach the burners and blowers. There is a pilot light or electronic ignition light, which ignites the gas and generates heat. The ignition light is present inside a metal box called the heat exchanger. The cold air drawn from outside is made to pass around the heat exchanger to heat it. This hot air is pushed into the hot-air plenum and then out to the rooms through duct work. The gas that is released due to this process is vented outthought flue in the roof or wall.

What are the parts of a gas furnace?

Just like central air conditioner, a gas furnace also has two units - the outdoor unit and the indoor unit. The furnace is the indoor unit that heats and circulates warm air through your home in the winter. The indoor and outdoor units are engineered to work together. The efficiency of furnace is measured in terms of Annual Fuel Utilization Efficiency (AFUE) percentage. A higher AFUE percentage indicates a more efficient furnace.

Here is quick look at the major components of a furnace:

• The burner: It is through the burner that gas is delivered and burned.
• Heat Exchanger: It is here that heat that has been generated due to the combustion of gas is discharged to air distribution system.
• Ductwork: The ductwork is present throughout the house that gives out heated air from the system to your living space.
• Flue or Vent Pipe: It is used to expel the by-products of combustion such as carbon dioxide and water out of the premises. These are generally made of stainless steel or PVC. PVC is commonly used as it is lower in price and also has higher durability. Type B gas vent pipes are the standard flues for gas furnaces.
• Ignition Controls: The advanced furnaces of today have circuit boards. These are useful to keep a tab on the system’s sound operation. If the furnace malfunctions, the light emitting diodes will display failure codes. You will see these error codes on the door of the furnace and the Owner’s manual.
• Safety Controls: The furnace system has a thermocouple that will shut off the gas if the ignitron fail or the pilot light goes out. It has two wires that are shielded case. When you put on the furnace, it sends signal to the valve by means of a solenoid. The thermocouple converts the heat into electric signal that allows the valve to close or open.
• Blower Motor: This motor runs the blowers that circulate hot air to all over the room.

What features to expect from gas burning system?

If you shop for gas furnaces in the market you will get an endless variety of them. It is easier said than done to know and select what is best for you. Here are guidelines to give you a clear understanding of the features that you should expect in your furnace:

• Blowers: They come in various types. It is these blowers that circulate hot air to your rooms. There are varieties in blowers. You can opt for fixed blowers that operate in one or two positions. These are quite good. You can also go for multi-speed bowers. But if you are looking for something better than that, then go for variable multi-speed blowers. The speed of these is customized by the furnace according to heating needs. The blower may operate at speed of 400 cam or 1600 cam depending on the setting of the thermostat or weather conditions.

• Intelligent controls:
The advanced gas furnaces come with intelligent controls that can perform an array of functions. These can monitor the indoor and the outdoor temperature. They can sense the indoor humidity level and adjust accordingly to provide a comfort level. They can monitor the airflow in your ducts and emit signal before problem arises. They can be operated with remote control. They will also tell you when your filter requires changing.

• Hot Surface Ignitron: Thesis Avery important component of a furnace. It ensures that there is enough sparks to combust the gas. There are two types of igniters today:

o Silicon carbide igniters: This is a standard one that can last for three to seven years,
o Nitride hot surface igniters: This is a better option with a greater longevity.

• Single Stage Furnaces: In these furnaces, when the burner is lit, the furnace runs with a constant gas flow.
• Two-Stage Furnace: Two-stage furnaces have two different settings for burner – high and low. When the demand for heat is not that high the furnace will run at lower mode. In bitter cold days, the furnace will switch to high heating mode and warm the room quickly. This a good option to reduce your heating expenses.
• Variable-Speed Furnace: These furnaces are able to provide more air to your room for longer periods. They prevent air stratification in rooms. They also improve air quality through filtration. They are noiseless and effective energy saver.
• Efficiency: Gas furnaces efficiency is measured through Annual Fuel Utilization Efficiency (AFUE) rating. All new furnaces have this rating. This rating ranges from 80 percent minimum to 98.5 percent. This percentage is derived from the amount of fossil used by furnace and part of it that is converted into heat. The best performing furnace will convert 98.5 percent of its fuel into heat. Furnaces that convert more than 90% of their fuel into heat are called high efficiency furnaces.

Furnaces manufacturers are coming up with new features to boost the efficiency of a furnace. One such effort was to replace pilot light within electronic spark light. The former burns gas even when the furnace is inactive. Electronic spark ignitron will burn gas only when heat is needed. Condensing gas furnaces are also energy efficient furnaces. These furnaces run the exhaust gases through a second heat exchanger that are otherwise released into the surrounding in ordinary furnaces. They take out nearly all the heat of the gas and send out cool air and water.

As they give out only cold water and air, the bi-products can be vented through a wall along an inexpensive PVC pipe. You do not have to bear the hassle of routing a flue up through the roof.

How Much Does a Furnace Cost?

Buying gas furnace is not as easy as buying anew washing machine or a window AC. You cannot look out and compare their prices in an online shop or in retail stores. Many competitive brands are not to be found with retailers. They are sold through HVAC dealers or wholesalers. If your old furnace has gone beyond repair and you want to get it replaced by anew one get in touch with a HVAC contractor. They will give you the quotes of buying it as well as that of installation. Buying and installing a new furnace along with getting a detailed duct work done is a costly affair. Check if you can connect the new unit with the existing ductwork and exhaust flue. The cost of residential gas furnaces can range from $2,500 and go up to $14,000. Purchasing and installing new unit without the need to make ducts will cost between $3,000 to $4,500, of course it will vary with the price of the unit.

If you live in palace with moderate climate, a furnace with medium efficiency will serve your purpose. But if you live in cold climate, you are left with no option button buy a highly efficient gas furnace from a good brand. However, natural gas furnaces are the best bets as natural gas is cleaner, more efficient, and less expensive than oil or electricity. It also has higher AFUE rating than other fuels.

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