Let us first understand what a gas furnace is. Gas furnace is the heating component in most of the systems which helps in raising the room temperature or heating the room in cold climates. In a gas furnace, the main fuel is gas and not oil. The major components of a furnace include burners, heat exchangers, blower, and controls. Most of the gas furnaces are designed in such a manner that they are highly energy efficient and runs for a long period of time. The basic principle that creates heat in a gas furnace is the combustion of gases.

However, in order to get most out of a gas furnace, it is important to keep certain things in mind while buying a gas furnace.

First of all, the size plays an important role. A furnace which is smaller in size will never give your home the desirable amount of comfort. To tackle this problem most of the times homeowners end up buying furnaces which are too big in size. An oversized furnace is also not suitable because it will cycle on and off more frequently, thus leading to more wear and tear of the machine. Hence, a correctly sized furnace is of utmost importance. To achieve that you will have to get in touch with an experienced HVAC contractor who will perform accurate load calculation and suggest you the rightly sized furnace.

The efficiency also impacts the performance and comfort level of a gas furnace. For example, a gas furnace with higher AFUE rating is more efficient and gives more comfort than the one with a lower AFUE rating. At the same time, gas furnaces with higher AFUE rating might be costly initially but in the long run the amount you save on monthly utility bills will make your initial investment worthwhile.

Thus, when you are buying a gas furnace keep a careful eye on the size and the efficiency rating of the system to maximum gains.

Now let us get an idea about the functionality of a gas furnace. A gas furnace starts reacting when the room temperature falls below the programmed setting on the thermostat. The heart of the furnace is the burner which in turn is controlled by the thermostat. When the room temperature falls below a certain point, the thermostat alerts the furnace which in turn combines the air and the fuel and this mixture gets ignited with the help of an electronic igniter. The combusted hot gas begins to rise through the heat exchanger that is situated above the burner and the hot air is circulated throughout the house. The remaining exhaust gas exits the household through a vent, which is then let outside the house.

This entire process begins at the heart of the system which is the furnace and it is controlled by the thermostat. There are some furnaces which come with two or more burners so that huge volumes of air can be combusted to produce higher amount of heat.

Last but not the least, take into account the area to be heated and the level of insulation that your home has before installing a gas furnace.