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Every Duct Has A Bill
By George Porter
Lately energy conservation has been making the news everywhere
and I think it's time that we, as installers, put our two cents
in to try to save the consumer some money. How well a home is
installed has a tremendous amount to do with how much heating
or cooling it will consume in its lifetime. A few extra minutes
and a few extra dollars during installation could affect the savings
of thousands of dollars in the lifetime of the home. If there
was ever a time for installers to market an energy efficient installation,
that time is now.
If for a couple of hundred of dollars you can save the customer
thousands of dollars, then you will have created a product that
should place you in high demand in your area as an installer.
The good part is you don't have to invent anything new. All you
have to do is adopt a few procedures that have been in place in
other parts of the country and they are so easy and make so much
sense that it is scary.
For example, suppose the customer orders a home with R33 insulation
in the ceiling, he special orders 6" walls with R19, and
he has thermal pane windows throughout the house. Everyone would
have to agree that this is an extremely well insulated home. The
next time you install a home like this, check the R rating on
the crossover ductwork that carries all the air from one side
of the house to the other and lays under the home in a very cold
area. It is R5.5 and it drastically affects the temperature of
the air when it comes out the ductwork on the other side of the
home. A system is only as good as its weakest link and if you
have R33 in the ceiling, R19 in the walls and R11 in the floor,
and R5.5 on your ductwork, then you've got R5.5. All that's required
to change all this is have the ductwork be at least the R value
of the walls in the home. Not all homes have exterior crossover
ducts, but most of them do.
One of the projects I do is working for a local power company
inspecting manufactured homes with extremely high heat bills.
90% of all the cases boil down to three things, and we're talking
about heat bills that are four times higher than anybody elses
in the area. The number one reason for a high heat bill is that
the ductwork has fallen off. The number two reason is the hot
water heater is set on 160 or 170, and the number three reason
is a dirty filter in the furnace.
As installers, we can't keep coming back changing the filter
for the homeowner. That's something he'll just have to learn to
do himself. But we can sure keep that ductwork from falling down.
When you install ductwork, bear in mind that what you do should
last forever, not just a year or two or three. That ductwork should
remain air tight, insulated and intact for the entire life of
the home. If, after a few years, some cheap duct tape dries out,
loses its adhesion and allows the ductwork to fall away from the
home, those people will use more energy in one month than ten
rolls of extremely high quality metal faced duct tape, and it
takes no longer to install it than it would with the cheap stuff.
There are many ways to properly connect ductwork on crossovers.
One of the best I have seen is using nylon zip ties, then wrapping
the entire connection with a heavy metallic duct tape and then
installing no less than four sheet metal screws through the metallic
duct tape into the metal duct from the home. Care should be taken
that these screws are installed below the nylon band installed
underneath the duct tape. You can increase the R value of ductwork
by simply wrapping it, usually with a heavy foil backed role of
insulation, covering it with heavy black Visqueen and securely
taping the whole thing with a high quality duct tape.
I have seen ductwork that consisted of little more than dryer
hose with heat tape insulation wrapped around it. The heat loss
on a 10 foot run of this stuff is probably near 50%. Ductwork
should not be laying on the ground. It should be as straight and
direct as possible and heavily supported underneath so that it
cannot develop sags to restrict the flow of air and cause condensation
to form when air conditioning is running.
There's probably also a tremendous market to retrofit already
installed homes with this kind of a crossover system. It pays
for itself handsomely and immediately. The air exiting on the
other side of the home may be as much as 10 to 15 degrees warmer
than it was before the ductwork was resealed and re-insulated,
and that's just for ductwork that isn't insulated. If the ductwork
has fallen off, there is no end to the savings that can be had
over that situation.
Give it some thought! As we said, every duct has a bill. Let's
hope the ones you install are low.