Tips to Choose a Gas Furnace: Types And Efficiency Ratings

Posted in Home Improvement

The gas furnace in your house is very important appliance and one you and your family depend on. So it must work reliably, efficiently and quietly. In this article I will try to explain the various types of gas furnace options which are available now, what you can expect from them in efficiency and what makes them different. So, there are different types of forced air heaters because of different technologies used to achieve the goals of energy efficiency and user’s comfort. In this regard this heating appliances fall into two broad category types: conventional and condensing types. It is the main reason why repair methods differ too.

images (2)

These heaters operation differs greatly. Conventional furnaces exhaust hot combustion gases very quickly so that gases leave the chimney before cooling and condensing. It results in the fact that heat exchanger does not gather as much heat from fuel combustion process as possible. Everything has changed with the advent of condensing heating appliances. Condensing heater captures heat even after combustion gases were cooled and condensed. It became possible due to two heat exchangers using simultaneously, one for primary heat exchange and another to handle condensed exhaust gases of carbon dioxide and. In this case, heat is extracted from exhaust gases until the water condensate drips out of unit’s heat exchanger and then flue gas escapes from plastic pipe instead of a chimney. As you see the differences in operation are significant, so if you are not sure of your furnace type, do not try to repair or fix it as it may be dangerous.

Heater types break down even further within main type categories of conventional and condensing, according to stages of burner and blower operation. These stages include: single stage units, two or dual stage units and modulating heaters. A single stage heater is the least expensive and means that burner and blower has one stage. A two stage has electronic controls, which allows the burner flame to be on at high and low settings, depending on what heat level is required. Modulating furnace has electronic controls for both the burner and blower motor, which allows very fine adjustments of burner and blower motor settings. All these appliances are safe and reliable, but sometimes there is a need to make a repair or replace some element. Do not be afraid as repair process is quite simple, in the majority of cases it can be performed with your own hands.

If you are considering purchasing of such heating appliances, you should be aware of their efficiency. It makes sense to organize heaters into such efficiency categories: low efficiency with 55% to 78% AFUE, standard or mid efficiency with 80% to 83% AFUE and high efficiency: with 90% to 98% AFUE. AFUE is an acronym for Annual Fuel Utilization Efficiency and it was designed to measures the amount of fuel converted into heat in proportion to the amount of used fuel. The higher the AFUE is – the more efficient the heater is.

Erik Pena in cooperation with repair furnace craftsman Steve Pope from providing useful tips on heating equipment proper maintenance.

About the Author

Back to Top ↑