Condensing Gas Furnaces

                                                          


Condensing gas furnaces are the highest efficiency furnaces presently on the market. If you are building a new home or replacing the old furnace in your present house these high efficiency natural gas furnaces are your wisest choice. They are simply the best  furnace to use in all homes with natural gas heating.

The reason for choosing a condensing gas furnace is mainly because of  the extremely high AFUE (Annual Fuel Utilisation Efficiency) which runs  from 90 to as much as 97 percent (in some cases a little higher). Old furnaces made in past decades will be found to have AFUEs of 60 percent or even less and medium efficiency  gas furnaces made at present have AFUEs of 78 to 84 percent.

It is easy to see that a high efficiency natural gas furnace will consume as much as 20% less fuel in normal operation. This results in a substantial saving in fuel costs which over a relatively short period of time will pay for the somewhat higher initial price of the more efficient furnace. On average a medium efficiency gas furnace costs about $1000 less than a high efficiency model.

Modern condensing gas furnaces use, approximately 33 to 40 percent less fuel than old furnaces and 10 to 20 percent less than medium efficiency units made at present. This not only reduces fuel bills substantially but as a bonus also cuts down drastically on  toxic environmental emissions which are thought to be at least partially responsible for environmental pollution and climate change.

The somewhat higher cost of purchasing a new condensing gas furnace will easily be recovered, in a relatively short period of time, through fuel savings.The savings will then go directly into the pocket of the consumer throughout the life of the appliance. An average homeowner with an old model furnace might save $300 a year, or even more, by installing a 97% efficiency condensing gas furnace.

Condensing gas furnaces are made in a variety of sizes to suit any type of home. They new furnace can usually be placed in the same spot as the old furnace it is replacing, and will typically use the same heat  duct-work. All furnaces must of course be installed by licensed gas installation technicians. It is very unwise to have an unlicensed do it your-selfer install your furnace. In many places it is illegal to do so, and could also result in your insurance company refusing to pay claims if there is a fire. For more information about condensing gas furnaces click here

                                                                 

Why Is A high Efficiency Gas Furnace Called A Condensing Furnace?

When you read the l;iterature about gas furnaces you will usually come across the term "condensing gas furnace" which is used to describe a type of furnace with the highest efficiency rating (AFUE). Medium efficiency furnaces are not called condensing gas furnaces. why is this?.

High efficiency furnaces with over 90% efficiency and running up to 97% efficiency are all condensing gas furnaces. Here is how  Manitoba Hydro  explains this.

High-efficiency condensing furnace
One of the by-products of burning natural gas is water
vapour, which contains approximately 10 per cent of the
fuel’s energy. However, in conventional and mid-efficient
furnaces all of the energy contained in the water vapour
escapes through the chimney.
A high efficiency furnace has a secondary heat exchanger
that extracts most of the energy from the water vapour by
condensing it to water. The water is then drained to a floor
drain, via gravity or an optional condensate pump system.
These units cannot use a conventional metal chimney.
The lower temperature flue gases are vented outside using
a special plastic venting system. Plastic pipe is used for
its corrosion resistance properties. The AFUE ratings for
high-efficiency, condensing furnaces is between 90-96
per cent. It is estimated that a high efficiency furnace can
reduce your home’s annual heating bill by up to 35 per
cent compared to a conventional furnace.
Your existing natural gas water heater can be left alone on
the existing chimney as long as it works properly and the
chimney meets the requirements of the National Natural
Gas Installation Code.
However, once the water heater is isolated on the existing
chimney, it may not work properly. Problems such as flue
gases condensing in the chimney, back-drafting or other
venting problems can occur. The chimney may have to
be modified to correct these problems. The most common
modification is installing a smaller diameter chimney liner
into the existing chimney.

The above material is quoted directly from a  Manitoba Hydro  publication. As they explain a condensing gas furnace actually cools burnt gases and extracts heat from them till they become cool enough to condense the water vapor portion of the gases. the liquid water is then drained from the furnace into a floor drain.
For more information about high efficiency furnaces see buy gas furnace and    high efficiency furnaces

Condensing Gas Furnaces Are The Most Efficient

                                                         

The most energy-efficient furnaces available are condensing gas furnaces. They are the best replacement furnace in all homes which are heated by natural gas. Here's the reason:

Condensing gas furnaces have an AFUE (Annual Fuel Utilisation Efficiency) of from 90 to 97 percent. Old furnaces commonly have AFUEs of 60 percent or even less and standard efficency furnaces have AFUEs of 78 to 84 percent.

Condensing gas furnaces use, about 33 to 40 percent less fuel than old furnaces and 10 percent less than standard efficiency units. This reduces toxic environmental emissions which may be partly responsible for climate change and air pollution.

The higher cost of purchasing a condensing gas furnace will be recovered, over a period of time, through fuel savings. An average homeowner with an old model furnace might save $300 a year or so by installing a 96% efficiency condensing gas furnace.

Condensing gas furnaces are made in all sizes to suit any home. They may be placed in the same location as the old furnace, and can use the same ductwork. All furnaces must be installed by licensed technicians. Read More