High efficiency furnaces convert more than 90% of the fuel burnt in them into actual heat for the home. This means that these furnaces will burn 35% to 50% less fuel than older furnaces of 60% or lower efficiency. Obviously the fuel bill for these furnaces is much lower than for the old low efficiency furnaces. Not only that but the high efficiency furnace reduces greenhouse gas emissions into the atmosphere by up to 50% also. This is extremely important since these gases are believed to be responsible at least in part for climate change and global warming. The USA is at present the worlds second highest contributor (just behind China) to greenhouse gas emissions. Here is some data from Wikipedia on the subject.
Since about 1750 human activity has increased the concentration of carbon dioxide and other greenhouse gases. Measured atmospheric concentrations of carbon dioxide are currently 100 ppm higher than pre-industrial levels. Natural sources of carbon dioxide are more than 20 times greater than sources due to human activity, but over periods longer than a few years natural sources are closely balanced by natural sinks, mainly photosynthesis of carbon compounds by plants and marine plankton. As a result of this balance, the atmospheric mole fraction of carbon dioxide remained between 260 and 280 parts per million for the 10,000 years between the end of the last glacial maximum and the start of the industrial era.
It is likely that anthropogenic warming, such as that due to elevated greenhouse gas levels, has had a discernible influence on many physical and biological systems. Warming is projected to affect various issues such as freshwater resources, industry, food and health.
The main sources of greenhouse gases due to human activity are:
burning of fossil fuels and deforestation leading to higher carbon dioxide concentrations in the air. Land use change (mainly deforestation in the tropics) account for up to one third of total anthropogenic CO2 emissions.
livestock enteric fermentation and manure management, paddy rice farming, land use and wetland changes, pipeline losses, and covered vented landfill emissions leading to higher methane atmospheric concentrations. Many of the newer style fully vented septic systems that enhance and target the fermentation process also are sources of atmospheric methane.
use of chlorofluorocarbons (CFCs) in refrigeration systems, and use of CFCs and halons in fire suppression systems and manufacturing processes.
agricultural activities, including the use of fertilizers, that lead to higher nitrous oxide (N2O) concentrations.
The seven sources of CO2 from fossil fuel combustion are (with percentage contributions for 2000–2004):
Seven main fossil fuel
combustion sources Contribution(%)
Liquid fuels (e.g., gasoline, fuel oil) 36 %
Solid fuels (e.g., coal) 35 %
Gaseous fuels (e.g., natural gas) 20 %
Cement production 3 %
Flaring gas industrially and at wells < 1 %
Non-fuel hydrocarbons < 1 %
"International bunker fuels" of transport
not included in national inventories 4 %
The US Environmental Protection Agency (EPA) ranks the major greenhouse gas contributing end-user sectors in the following order: industrial, transportation, residential, commercial and agricultural. Major sources of an individual's greenhouse gas include home heating and cooling, electricity consumption, and transportation. Corresponding conservation measures are improving home building insulation, installing geothermal heat pumps and compact fluorescent lamps, and choosing energy-efficient vehicles.
Carbon dioxide, methane, nitrous oxide and three groups of fluorinated gases (sulfur hexafluoride, HFCs, and PFCs) are the major greenhouse gases and the subject of the Kyoto Protocol, which came into force in 2005.
Although CFCs are greenhouse gases, they are regulated by the Montreal Protocol, which was motivated by CFCs' contribution to ozone depletion rather than by their contribution to global warming. Note that ozone depletion has only a minor role in greenhouse warming though the two processes often are confused in the media.
On December 7, 2009, the US Environmental Protection Agency released its final findings on greenhouse gases, declaring that "greenhouse gases (GHGs) threaten the public health and welfare of the American people". The finding applied to the same "six key well-mixed greenhouse gases" named in the Kyoto Protocol: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.
In 2005, the world's top-20 emitters comprised 80% of total GHG emissions (PBL, 2010. See notes for the following table). Tabulated below are the top-5 emitters for the year 2005 (MNP, 2007). The second column is the country's or region's share of the global total of annual emissions. The third column is the country's or region's average annual per capita emissions, in tonnes of GHG per head of population:
Top-5 emitters for the year 2005
Country or region % of global total
annual emissions Tonnes of GHG
China (b) 17 % 5.8
United States (a) 16 % 24.1
European Union-27 (a) 11 % 10.6
Indonesia (c) 6 % 12.9
India 5 % 2.1
These values are for the GHG emissions from fossil fuel use and cement production. Calculations are for carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and gases containing fluorine (the F-gases HFCs, PFCs and SF6).
These estimates are subject to large uncertainties regarding CO2 emissions from deforestation; and the per country emissions of other GHGs (e.g., methane). There are also other large uncertainties which mean that small differences between countries are not significant. CO2 emissions from the decay of remaining biomass after biomass burning/deforestation are not included.
a Industrialised countries: official country data reported to UNFCCC.
b Excluding underground fires.
c Including an estimate of 2000 million tonnes CO2 from peat fires and decomposition of peat soils after draining. However, the uncertainty range is very large.
The above material is quoted from Wikipedia
The above figures clearly indicate that China, the USA and India must reduce their greenhouse gas emissions to stabilize climate change and avoid disastrous global warming. Unfortunately all three countries refuse to participate in international agreements to reduce emissions.This makes it all the more important for individual consumers to reduce their emissions as much as possible. Installation of a high efficiency furnace is a good start to this. Go to our website at gas furnace costs for more information and also at
high efficiency furnaces.