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Preventative
Maintenance
We all know
somebody who is into gizmos and gadgets. They have to have the latest of the
newest whether they really have a need or not. Usually it's hard to warrant a
need for most of the consumer electronics but marketing keeps us believing we
can't live without these great gadgets. There are now almost 2 billion cell
phones in the world and the use keeps on growing. Yet 10 years ago almost nobody
had one. Sometimes I wish cell phones were never available. But I've been
starting to believe these technological advances are coming from beings on other
planets because it's just difficult to understand where all the inventors and
geniuses are coming from that are creating these gizmos and gadgets. Especially
all the technological advances in technology, medical, manufacturing and
military technologies. Is this really human? I continually see new computer
technologies and software with new software updates while I'm still coping with the first
releases. I'm not only perplexed at the continual growth in the software
industry but who are these people that have mastered all the technological
advances of these programs that I have to need more? Did I get dumber or did the rest
of the world get smarter? I don't see the people in my little world getting
smarter. In fact the opposite has been my observation. So it must be Martians or
beings from another planet.
Then after seeing
all these technological marvels I see recent reports more people are being
maltreated in hospitals by doctors and nurses than at any other time. After all
these technological advances? This same recent report says the equivalent of a
jumbo jet load of people die every day from staph infections due to doctors
simply not washing their hands before examining patients or surgeries. It's
reports like this that make me question if we are responsible for all these
technological miracles when doctors can't or won't take time to wash their
hands.
But technological
advances have been slow to be accepted in the HVAC industry unlike other
markets? Why? The  technicians in our industry have difficulty even accepting
their own responsibility to do a basic Manual J load calculation to determine
the correct size system to be used. In fact to go along with the technological
advances that have taken place in so many other industries it is more important
those technologies are reliable, useful and perform in all types of
environments for the HVAC industry. Many of those technologies have proven reliable useful performance
with variable speed ECM blower motors now having over 15 years of reliable
service. With two stage air conditioning, intelligent solid state igniter controls and
ultra efficient condensing gas furnaces it's exciting to see where technological advances can be used
successfully in HVAC systems. But most contractors only propose the basic
builders model equipment. Why? A certain mind set has developed in HVAC
contractors that homeowners
aren't interested in spending extra money for more efficiency and technology.
They think it's all about the lowest price. But
if that were true than only the most competitive priced brands would sell the
most equipment. And that's not true. The reason HVAC contractors don't sell more
high technology equipment and systems is because they don't bother to show
homeowners a value and return on their investment. In other words if contractors
and technicians don't embrace the technologies themselves how do they expect
their customers to do so? There has been more recent marketing by some HVAC
contractors in light of the recent energy crises but on the whole most have
little marketing skills and rely entirely on the manufacturers they represent to
do it for them. The manufacturer's goals at marketing the new technologies
haven't exactly been stellar either.
So in light of all
the technological advances and developments the HVAC industry isn't really much
different than the medical profession. Where all have failed is in educating
homeowners about the need to keep their systems clean. Yes in spite of all the
latest technological advancements most homeowners don't bother to change air
filters or keep their systems in 100% operating condition. Preventative
maintenance is the third biggest cause of system failures in the HVAC industry.
The first two problems of oversizing of equipment and undersized air
distribution systems can be blamed on HVAC contractors but lack of preventative
maintenance is the single biggest homeowner related item that causes system
failures. A dirty filter can reduce efficiency of a system by 50% or more. Dirty
coils and clogged heat exchangers not only waste energy but destroy the
equipment.
Unless attention
is paid to the basic preventative maintenance of existing systems homeowners
cannot expect new equipment to magically create continual energy conservation
and longevity. Understanding the role of the homeowner in preventative
maintenance is as important as the equipment itself. Homeowners often times feel
their only role is to change filters, check the thermostat setting and make
certain diffusers are open and unobstructed. Yet most technicians report that
simply finding the furnace or air handler in a house can be a real challenge. Many times the
equipment is surrounded by clothing or boxes where it is completely ignored.
Filters are many times completely clogged or missing entirely. The frightful
homeowner response of "Gee, is there supposed to be a filter in there?". Only
when homeowners are challenged to change their roles of passive to active
participant will they realize the value of preventative maintenance. We're not
simply talking about changing filters. Even with filters, it isn't changing the
filter that is as important as the type of filter used and the purpose of
keeping filters clean. It's where the filter is located and how much dirt can
actually bypass the filter, how much dirt has accumulated on the furnace or
indoor coil, how to remove that dirt and how to keep the coils clean. The
average home wastes anywhere from 25 to 40% of energy due to improper
preventative maintenance. That figure can be higher if the system has been
neglected for a long period of time. The "I'm too busy" excuse doesn't make
sense when considering the amount of energy wasted can pay off even to the
highest income levels.
Coils
So let's take a
look at what an active serious homeowner energy conservationist would do to
their home heating and air conditioning system. Assuming this is a home that was
a recent purchase our homeowner would first look at the air filter. If there is
no air filter you can automatically assume the coils and heat exchangers are
clogged with dirt affecting heat transfer. If there is a standard fiberglass
filter similar to those sold at home centers you can also be assured most of the
dirt the filter is supposed to catch bypassed the filter and was attached to the
coils and heat exchanger surfaces.
Coils need to be
physically inspected if they are to be operating efficiently. In air handlers
and furnaces with air conditioning coils there can be several coils. For
example a gas furnace using pvc as venting materials will have condensing coils.
These condensing coils look similar in appearance to air conditioning coils. If
the air filtration is questionable or isn't a high media or pleated type of
filter the assumption should be made the coils have dirt accumulation. In the
case of the condensing coil this dirt will usually melt on to the surface of the
coil and will be difficult if not impossible to remove. Operating the gas
furnace and placing a thermometer on the outlet of the pvc plastic discharge can
give a good indication of the performance of the furnace and the condensing
coil. If the temperature of the flue gas is 120 degrees or more you can be
assured the furnace has a problem and is not operating at the efficiency levels
to which it was designed. Again back to the original suggestion of checking the
condensing coil visually for dirt accumulation. This will involve removing
ducting and looking at the air entering side of the coil. indoor air
conditioning coils must also be inspected in the same manner form the entering
air side of the coil. Since the vast majority of air conditioning coils are of
the A type design, a visual inspection hole must be made to inspect the air
entering side of the coil. An inspection mirror and flashlight will allow the
entry side of coil to be inspected. If the wrapper on the coil was installed by
the installing technician rather than a cased coil, it may be easier to remove
and inspect. However the sheet metal is going to be attached to the connecting
ducting and requires removal which may be difficult. Therefore an entry hole for
inspection may be the most expedient method of checking the coil surface. Asking
an installer or making the visual inspection access during original installation
is easy and can be done without additional cost or inconvenience.
Inspection access for gas furnaces before the condensing coil can also be easily
accomplished but will most likely met with resistance from the installing
technician as it is a highly unusual request.
The
most accurate method of examining a coil is to shine a light from the entering
side to the leaving side and visually inspect for dirt accumulation that exists
between the fins of the coil and builds up on the copper tubing. Depending on
the thickness of the coil and the spacing of the fins dirt accumulation can
vary. Some coils will build up solely on the entering face of a coil while other
accumulate in between the fins then later blocking the face of the coil. In any
event he coil must be inspected thoroughly using lighting between the fins from
one side to the other.
Heat Exchangers
In addition to
inspecting coils and heat exchangers on the indoor unit the outdoor coils must
also be inspected. It is very possible and happens quite frequently that a coil
shows no dirt accumulation on the entering surface but when a light is shining
through the coil will reveal substantial dirt accumulation. Outdoor coils should
be cleaned regularly with a garden hose. Make certain the electrical power is
first disconnected and the motor is protected form water entering. After
cleaning allow the system to dry for 24 hours before restarting. In an outdoor
unit that hasn't been cleaned or excessive dirt has built up use a pressure
washer to properly clean the coils.
Cleaning of coils
can be accomplished with chemicals and high pressure water. Chemicals used for
cleaning coils will vary depending on the type of coil. Indoor coils use milder
cleaning agents while outside coils use very strong cleaning agents which can be
dangerous and toxic. High pressure sprayers are great for producing cleaning
results when accompanied by cleaning agents. Care needs to be taken to make
certain the high pressure does not bend the aluminum fins over and
consequently reducing air flow and heat transfer.
Also coil fins
must be checked for straightness and alignment. Fins can be straightened and
aligned with a sharp knife if severely bent and then a fin comb. A fin comb is a
plastic specialty comb used to realign the aluminum fins of coils. Fin combs can
come at a specific number of fins per inch spacing. Universal fin combs have
various fin combination head spacing. If you don't have a fin comb the process
can also be accomplished successfully with a knife and individually aligning the
fins to their correct position. Bent fins like dirt reduce heat transfer and
waste energy as well as cause destruction to furnaces and air conditioners.
In addition to
affecting heat transfer dirt accumulation in a duct system can also breed
allergens and all types of creatures including dust mites and mold. A
professional cleaning of the duct system may be required if there is evidence of
substantial dirt accumulation on the coils.
Filters
To avoid dirt
accumulation in your HVAC system look at the filter you intend to use. Put the
filter up to the light. If you see gaps typical of those found in fiberglass
filters sold in home centers realize how much dirt will bypass the filter and
accumulate within the system after several years of use. If you can see directly
through the filter don't waste time and money purchasing and installing it. 3M
types of pleated filters which provide a solid filtration barrier are essential.  The
best solution is a high media filter which is four or five inches
thick placed before the entering side of the furnace or air handler will provide
excellent filtration for months at a time before it needs to be replaced. Or
using pleated filters in conjunction with return air filter grills stopping dirt
form entering the duct system completely. If the cost of a pleated filter seems
too expensive in comparison to the cheap fiberglass filters all you have to do
is think of the energy losses that will occur with the cheaper filters. Most
fiberglass filters are great for catching large flies and rodents. Although
somewhat better than no filter the purpose of the filter is to keep the
equipment clean and energy efficient. Fiberglass filters do not accomplish this
task. Most homeowners believe air filters are for cleaning up the indoor air
environment. Nothing could be further from the truth as filters protect the HVAC
equipment and effectively keep the system operating at maximum efficiency. Why
aren't electronic filters recommended? After 40 years in manufacture electronic
air filters continue to have a high rate of failure and it is difficult to check
their proper operation. When they fail electronic air cleaners give no warning
and will cause system components to accumulate with dirt and decrease efficiency
before the problem is discovered.
Ducts
Another important
function of preventative maintenance is to inspect duct systems for leakage and
proper insulation. Ducting
exposed to unconditioned spaces such as attics and crawl spaces need to be
properly insulated with at least an R-6 insulation. Further most sheet metal
duct systems leak at least 25 cents of every energy dollar.Those
duct seams and joints need to be sealed with rated duct mastic,  UL
approved aluminum duct tape or high temperature silicone caulking. Do not seal
ducts with duct tape such as you find at building centers. Unless the duct tape
is Ul rated for HVAC systems the glues in duct tape will not with stand the
various temperature differences and soon fail. Remember that ducts whether they
are return or supply ducts need to be sealed and insulated equally. For many
years it was ignorantly said only supply ducts need to be sealed and insulated.
Return ducts are equally important in your goal t achieve energy efficiency.
Also not he ducting that exists after
the air filter needs to be without leaks
as any air that is pulled into the duct system will be unfiltered and cause dirt
accumulation of heat exchangers.
 Insulation on
ducts may fail due to moisture build up or the failure of duct tapes. Once
insulation becomes wet or damp it losses it's insulating capabilities. Duct tape
around duct joints will also fail after several years as most tape is not rated to
withstand the pressure and temperature
demands of HVAC systems. Insulate ducts without insulation or deteriorating
insulation making certain to seal the joints first.
Condensate and
Traps
A most overlooked
item in preventative maintenance is the condensate line and trap. Traps are now
being utilized more because of condensing furnaces which requires use of traps
in winter in addition to air conditioning during the summer. Many times when
traps are installed there is no access union. However this is a quick repair.
Cut out the existing trap if no access unions are available. Take the trap and
run hot water through it to break up and remove dirt and accumulated debris.
Traps should always be installed with nothing less than 3/4" pvc.  Copper
and steel pipe traps become corrosive and block the flow of debris. For this
reason it is best to use pvc plastic. If access to the trap is difficult use
pressurized air and hot water to blow the trap clean. However the best method is
to have an easily removable trap that can be readily cleaned once per
year for systems with air conditioning only or twice per year for systems with
condensing furnaces and air conditioning.
If the air handler
or furnace is located above ceiling areas where a blocked trap and the
resultant damage and destruction from the condensate would be costly, install an
alarm such as a wet switch. In horizontal applications there should always be a
condensate pan which works as a secondary protection. Place the alarm in the pan
or there are also alarms which can be placed directly in the condensate trap.  The
alarm should also be wired to the air conditioning to prevent operation if water
is detected preventing destruction. We do caution you however in wiring gas
furnaces to alarms. If water is detected the alarm will shut off the heating and
if nobody's home or away on vacation the resultant shut off of the furnace could
potentially cause water pipes freeze and burst causing more than minor destruction.
Refrigeration
Lines and Charge
Refrigeration
tubing or line sets that are used to connect air conditioning or heat pumps
require insulation on the larger suction line tubing. This insulation
may fail after several years and needs to be replaced.
As you are trying
to keep your HVAC system up to maximum performance levels have an HVAC
professional check and adjust the refrigerant charge. More than 50% of air
conditioning and heat pump systems are under charged causing significant losses
in performance and excessive energy consumption. Simply by having your HVAC
system charge adjusted to maximum performance can reduce energy consumption by
25 to 60% on average. Adding refrigerant charge to any  system on a regular basis
without finding the source of the leak and correcting it not only causes capacity
losses but wastes energy and ultimately results in premature equipment failure.
If the service company you're using doesn't bother or can't find the leak, get
another company that cares. Leaks almost always occur at joints either in the
interconnecting lineset or in the unit itself. The basic method of using a soap
detergent mixed with 1.5 parts of water or with sufficient surface tension and
an acid brush will effectively find 99% of all leaks. Sometimes leaks will occur
in the center of coils or tubing. When numerous leaks begin to plague a system
they can be very expensive to locate and repair. A cancerous condition can occur
within the system caused by acidic oil which will effectively eat away at the
copper tubing. Systems affected by severe problems of acidic build up and
deterioration can either be treated with additives or replacement of the system.
Some systems become so plagued with acid that electrolysis begins to leach
copper from the tubing and copper plate the compressor. Also anytime the
refrigerant system is worked on and exposed to atmospheric conditions a new
filter drier must be installed as a preventative measure. The filter drier used in
burn outs or acidic conditions as described will assist at neutralizing oil and
removing moisture from the system. Refrigeration systems are extremely sensitive
to moisture, dirt and acid. These items are classified as contaminants and can
quickly destroy any refrigeration system.
Chimneys and
Venting
If your present
heating system uses a chimney it is imperative the chimney is inspected every
year. If there is no liner in the chimney one should be installed. If your
chimney has continuous debris accumulating at the base of the chimney the
chimney needs to be cleaned, lined or abandoned. Due to the high prices of
natural gas it is always recommended to have a high efficiency gas furnace
installed which eliminates the need for a chimney. Beginning in 2006 the
Department of Energy will be offering tax credits for gas heating systems that
are installed with 95% efficiency or greater. Also further rebates for ultra
efficiency air conditioners, heat pumps and variable speed motor options are also available allowing for up to a $300
tax credit. If your existing furnace or boiler uses a chimney there are substantial
energy savings and safety reasons to abandon the use of a heating system
requiring a chimney. If you have no chimney or your present chimney is in total
disrepair and you present system requires a chimney consider installing a side
wall vent kit as shown in the illustration.
Other Areas
The following
items are generally not considered normal preventative maintenance but should be
considered as part of any preventative maintenance program. The goal is to
provide safe energy efficient operation and maximize equipment longevity. Any
and all items that enhance the performance and achieve these goals need to be
considered.
Outdoor units are
now required to have GFI Ground Fault Breakers with electrical outlets in most
areas. As mentioned previously cleaning of these coils on an annual basis should
be part of every routine preventative maintenance program. Having safe
electrical power to your outdoor equipment should also be considered part of
this procedure.
In addition
upgrade the present thermostat to the more hi tech thermostats. Newer
thermostats do much more than control the temperature and are part of energy
efficiency and energy management. Utilizing total control of the HVAC by
providing efficient operation with reminders for changing filters and monitoring
the hours of operation of the equipment provide useful information for service
and efficiency. In addition the new hi tech thermostats change temperatures
during unoccupied or nighttime operation and reestablish temperatures
efficiently which are important for reducing energy consumption and reducing
wear and tear.
Some service
technicians are really into preventative maintenance while most are not. Knowing
the difference can make substantial improvements to the energy efficiency of
your heating and air conditioning system. Realize most homeowners can save 25 to
40% of their energy consumption by doing a thorough preventative maintenance
program. After you have maximized the basic efficiency of your heating and air
conditioning system, you can then effectively consider replacement of the
equipment to further increase your energy savings. But realize there are no
fancy gadgets or gizmos that can take the place of basic preventative
maintenance.
When is it time to
replace the HVAC equipment? Whenever the replacement of the system will provide
cost effective returns on your investment or repairs or total system failure is
close at hand. The last thing you want is to deal with an unexpected
replacement. There's no time to shop or consider a do it yourself installation
if your system fails in the dead of winter or when the hottest days of summer
are upon you. Here are some certain times when it is best to replace your
present system. If the system is ten years or older. If the heating efficiency
is less than 90%. If the Seer efficiency of the cooling or heat pump system is
8.0 or less. If the system has had repeated service calls in the past two years.
If the replacement system can reduce your energy consumption by 35% or more.
For more
information on preventative maintenance visit our library section. For questions
call DESCO Energy toll free at 877-265-9764 or email info@descoenergy.com
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