Updating Your HVAC System

The shock of skyrocketing utilities bills may have you thinking
about upgrading your HVAC system…. and rightly so, because
there is no chance the fuel costs are going to go down.

The newer heating and air conditioner systems are much more
efficient than older units and offer significant long-term energy
savings. The Government has mandated that any cooling units
should have a SEER rating of at least 13 starting in 2006 and this
is good, because a twenty-year unit may have a SEER rating of
only 7 or 8. However, for real savings you should look at your
whole home as an energy eating beast that needs to be put on
a diet. This includes repairing air leaking windows and door seals

It does little good to replace an older HVAC system and expect
great reduction in utility bills, if you don’t attend to the areas where
you are losing energy. New HVAC systems are expensive and
the temptation may be to just install a new high efficiency furnace
and air-conditioning system and hope for the best. The fact is, the
reduction in utility bills may be disappointing because you may
have overlooked a major player in the whole HVAC system….
like the ductwork.

A poorly designed, leaking and under insulated ductwork system
can waste 30 percent or more of the money you pay to run your
heating and cooling system.and nullify any gain you might realize
by installing a new high efficiency system. Many duct systems
are poorly insulated and leak conditioned air into un-conditioned
attics and crawl spaces. I commonly find disconnected ductwork
during my home inspections.

When ducts leak, conditioned air can be forced out unsealed joints
and lost. In addition, also un-conditioned air can also be drawn into
return ducts through unsealed joints. Attic temperature can be very
high in the summer and cold in the winter…so, any attic air that
enters your system through un-sealed duct joints will have to be
cooled in the summer and heated in the winter, this increases the
load on your system and increases your energy bill.

Surprisingly an older home may have a much better designed duct
system than a new home and may only need a leak check and
insulation upgrade. Newer homes on the other hand may be
victim of cost cutting measures and poorly designed duct systems.
The use of flex duct has grown in popularity because ease of
installation and the high cost of shop made sheet metal ducts.
Flex ducts even installed properly are a poor substitute for well
designed properly insulated sheet metal ducts. It is common
practice to make plenums and coil boxes out of taped together
duct board.

Be sure to include an evaluation of your ductwork system in your
plans to upgrade your HVAC system. There is no use in exhausting
valuable conditioned air to the great outdoors through leaks and
worn-out duct insulation. If your duct system needs an overhaul,
you might want to consider a high velocity delivery system that uses
smaller PVC pipe ducts. These high velocity systems are much
easier to install and insulate. The bottom line on a HVAC system upgrade
for maximum efficiency must include more than just the new equipment.
Don’t forget about the duct work and include it into your budget.

Jim McDonald is a retired contractor and a licensed home inspector