FURNACE
• Buying New
• Service Information
• Furnace Inspection
PURCHASING A NEW FURNACE
When purchasing a
new furnace the company that installs the furnace is
a more important consideration than the brand
name that is on the furnace.
A furnace is just a part of the system that heats your home and furnishes
air flow to cool your house. An 80% or 90% efficient furnace may loose
5% to 15%
of its efficiency or more if the rest of the system does not work properly.
Listed below is information that will assure that your new furnace delivers
the efficiency that it should.
It is important to do heat load calculations
before you install a new furnace. The
furnace should be the right size for your house. You or the previous
owner
may have added insulation, new windows or made other improvements that make
you home more energy efficient. A properly sized furnace will give you
more comfort
and cost less to operate. A properly sized furnace heats your house more evenly!
[see heating and cooling load calculations]
The manner in which your furnace is connected to the duct work affects
the efficiency of the heating and cooling system. Here
are a few examples:
Your ductwork is also an important part
of your heating and cooling system Good duct work leaks approximately
10% and poor ductwork leaks
as much
as 30% or more. In order to have ductwork
that leaks less than 10% it is necessary to seal the joints. If you
close a damper or register to try to balance the
system, all that
happens is that the duct work leaks more. You do not get, more air out of
the other registers. If the ductwork is tight and you close a damper
or a register,
more air comes out of the other registers. [Joint sealed with foil tape]
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Not Sealed |
Sealed with foil tape
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If you install a new 80% efficient furnace,
and connect the flue of the furnace to a chimney, the chimney must be
lined with a
metal
flue
liner.
If you do not have a flue liner the condensation from the furnace
flue will damage the chimney due to freezing water as well as rust out
the heat exchanger in your furnace. In
many cases (always if the furnace is two stage) double wall or “B” vent
must be connected from the furnace to the chimney or the existing “B” vent
that goes up to the roof or the condensation from the flue will rust out
the heat exchanger pre-maturely.
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Picture of "B" vent connected to furnace |
Double wall "B" vent |
Most filter racks that come
with the
furnace make it very difficult to change the filter. If the filter is
difficult to change it does not get changed as often. We recommend
a custom made
filter rack that makes it easy to change the filter.
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Custom made filter rack |
Which kind of furnace is best for you. It
depends! Furnace manufacturers make 80%, 90%,
efficient furnaces as well as two stage, 80% efficient
and 90% efficient
furnaces. Modulating 90% efficient are also available. Manufacturers
make a variety of furnaces because one furnace does not fit everyone’s
needs. We will explain the differences between the various types
of furnaces so that you select
the best furnace for you. One of the more important
questions is how long do you plan to stay in your home?
If the construction of the house is tight, it is recommended that
combustion air be supplied for the furnace. Combustion
air is air that is supplied to
burn the gas at the burners. A lack of combustion air causes incomplete
combustion.
If the proper amount of combustion air is not supplied to the furnace,
the result can be carbon monoxide. A flue problem can also be a
serious
health risk and
can result in death due to carbon monoxide. There are several ways to
protect your self.
If you do not have a carbon monoxide
alarm, we recommend that
you purchase one with a digital read out that indicates the level
of carbon monoxide
in parts per million. If it is more
than a few years old make sure that it works! Check the manufacturers
instructions.
Place the carbon
monoxide
alarm where you
can hear it if you are sleeping.
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The problem with a tight house is that if the kitchen or bathroom
exhaust fan is on, or a clothes dryer is running, air is removed
from the
house. The replacement
air will come in down the chimney or flue if the house has tight construction.
This can cause large amounts of carbon monoxide to be formed when the
furnace is running.
There are three ways to insure combustion
air for the furnace.
First most 90% efficient furnaces
have a dedicated combustion air connection to the furnace. This
type of furnace should have two large white PVC
pipes connected to it. One PVC pipe is for the flue exhaust and
the other
PVC pipe is for the
combustion air. If you have only one PVC pipe coming from a 90% efficient
furnace you do not have outside air for combustion.
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Pictures of white pvc
combustion air and exhaust pipe for 90% efficient furnace |
The second method is to have combustion
air coming from the attic or from an outside vent into the furnace
room. This
type of system is
generally used with
80% efficient or older furnaces.
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| Combustion air pipe coming from ceiling
and is shown in the center of the photo |
The third method is to bring in outside
air through the furnace duct system by connecting a duct from the outside
to the return air duct. Some
systems operate the furnace blower three or four times per hour even
though
the furnace or air conditioner is not operating, to bring in fresh
air into the house. There are
heat exchangers that can be connected to this type of system to
reduce the energy loss of bringing
in fresh air from outside.
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Picture of heat exchanger
used to save energy when bringing in air into house
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We recommend that the furnace that you purchase has a spark ignition
system for lighting the furnace rather than a hot surface
ignition system. Hot surface
igniters have to be replaced as often as every year or two and
the cost
is between $150 and $200. Consumers have reported that the most
common
problem
with their furnace
is due to a malfunction of the ignition system.
We give our customers a one year labor warranty with any furnace installation. Contact
us for details.
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For immediate 
