Do You Own an Inefficient Furnace?

You are reading this article because yourcosts you money while contributing to global
wondering how old, or how inefficient your oldwarming.
furnace/heater is, and whether or not it has a bigYour furnace uses fuel at a much higher rate than
carbon footprint. I will specifically talk about naturalit should and it produces wasted carbon dioxide at
and propane gas fired furnaces and heaters.a much higher rate than it should. Your furnace
Some people call them a furnace, some call themhas to have a metal vent pipe because of the
a heater, if they don't have the word condensingtemperature of the exhaust gases. A condensing
in front of them I call them inefficient. If yourfurnaces exhaust gas is cooled so much that the
furnace does not make water when it operates,vent pipe has to be made of PVC because they
then it is inefficient.make water when they run.
In California and according to PG&E: (PacificIn the old days a furnace with an 80% AFUE
Gas & Electric) Companyrating was considered to be high efficiency and
Burning one Cubic foot of natural gas will producemany of them came with a sticker that said high
13.446 lbs of carbon dioxide. All furnaces willefficiency on them. But once the first Condensing
produce carbon dioxide because it is a byproductFurnace came out and natural gas consumption
of burning natural gas. Go out side and clock yourstarted to soar - the 80% furnace with a single
PG&E meter while the furnace or heater ispass heat exchanger became inferior in terms of
on for a full minute then multiply that figure by 60energy efficiency.
minutes to get your total cubic feet per hour.If your using an old furnace with a metal vent
Multiply that number by 13.446 and you can seepipe, then you are behind the times. It is sort of
how much carbon dioxide that your furnacelike driving one of those great big long American
produces in one hour.made cars of the late 70's with an enormous
If your furnace does not remove 90% or moreengine, during the gas shortages. A condensing
of the heat from the total number of cubic feetfurnace is like driving one of today’s hybrids.
of natural gas burned before the gas is ventedExtremely energy efficient, saves gas and low
out of the furnace, then it is absolutely inefficient!pollution.
You ask "how can I tell if it's removing at leastA condensing furnace is safer too, in that most
90% of the heat" from the burned gas that iscondensing furnaces have totally enclosed
vented out of the furnace?combustion chambers which protects from total
This is the easy part. Simply look at the furnaceflame roll out in the case of a failed induced draft
exhaust pipe - if it is metal, about 4-5" in diameterblower motor. I am 100% sold on condensing
and it gets really hot, hot enough to burn yourfurnace technology, so much that I don't provide
hand after its been operating for a while, the80% low efficiency furnaces as one of the
furnace is inefficient. It's a gas hog, a grossproducts we carry, you won't find any links to
polluter in my book. In comparison to a 98%low efficiency equipment on our website. As a
efficient furnace. Your old furnace is like a carresult our customers get longer heat exchanger
that gets 14 miles to the gallon when it could getwarranties, limited lifetime warranties on a
30. Some condensing furnaces have a rating ofcondensing furnace vs. 20 year limited warranty
98% AFUE (look it up) which means it removeson an 80% furnace.
98% of the heating value from the burned fuelTake a look at your utility bill and see how many
before it is vented out of the furnace.therms of natural gas you consumed last month,
In terms of the amount of useless carbon dioxidehow many therms were in the base line usage
the 80% furnace produces, a furnace that has anand how many were in the over base line
AFUE of 98% delivers almost 100% of the heatcategory. If you’re over base line usage is
value of the fuel into your home as a result ofhigher or close to your base line usage, it's time
producing that 13.446 lbs co2 per cubic feetto change that old gas furnace out to something
consumed. Its wasted co2 production factor ismore modern.
only about .446 lbs per cubic foot consumedThe best way to understand the waste your old
because it only has one heat exchanger,furnace produces, is to imagine that you run your
condensing furnaces have two..furnace for one hour this morning trying to heat
In contrast an 80% AFUE furnace with a metalyour home. For the first twelve minutes of that
vent pipe is not only inefficient in terms of heathour your system does not blow any of its heat
value delivered to your home, but it is extremelyinto your home, but blows it to the outside and
inefficient in terms of producing heat as a resultyou do not feel any of the warmth that you are
of producing carbon dioxide or Co2. You can dospending money on. That’s essentially what
the math your self and see that for every cubicyou are doing by utilizing an inefficient furnace. By
foot of natural gas your old furnace consumes.tomorrow that 12 minutes will be 24 minutes of
You are producing more wasted carbon dioxidetwo hours, 36 minutes of three hours and so on.
than a condensing furnace would at a rate ofAt some point the money you waste in using
about 3lbs per cubic foot of natural gasthat old furnace will pay for most, if not all of a
consumed. More Co2 than a condensing furnacenew condensing furnace.
would, that gives you no direct benefit, and which