Gas furnaces are used on a massive scale in America today. And thirty-five million of those are low-efficiency furnaces that waste 30% of the fuel they consume. Additionally, these low-efficiency furnaces emit carbon dioxide, which contributes to air pollution. Choosing a high efficiency gas furnace, instead of a traditional unit, not only lowers your monthly fuel bill but also helps protect the environment and our energy resources.
When you’re thinking about replacing or upgrading your heating system, one of the main considerations should be efficiency.
The AFUE (Annual Fuel Utilization Efficiency) is a unit that determines the percentage of fuel turned into heat and also the amount of gas that goes to waste. Modern high efficiency furnaces have ratings of 90-95% AFUE. This means that 90-95% of the fuel is used to maintain a warm room temperature, while 5-10% is lost to exhaust. The efficiency of the furnace increases with increasing AFUE, resulting in maximum benefit with minimal loss.
Following is a comparison of furnaces with various energy efficiencies.
High Efficiency Furnaces
Advantages: These units have an AFUE of 90-95%. If you live in an area with harsh winters, you should recoup the additional expense of a high-efficiency furnace (90% AFUE or more) over the lifetime of the system. These types of furnaces do not require a traditional chimney; the exhaust gases cool off so much while passing through two heat exchangers, they can be horizontally vented directly to the outside of your home, making furnace location more flexible. Disadvantages: High efficiency furnaces require a higher up-front investment. They require a drain to get rid of the condensed water created from the heat exchange process. They are also more technical and should be worked on by a certified technician to protect your warranty.