Jacksonville's Air Duct Cleaning Specialists
How To Do an AC System Checkup
Top of Compressor removed for cleaning
Two Air Handlers
ANNUAL CHECK UP
It doesn't take a rocket scientist to know that preventative
maintenance costs a lot less than waiting until something breaks
down. The same holds true for your air conditioner and heat
pump. If you don't service them, you'll find yourself
uncomfortably hot or cold and broke.
An air conditioner is a very tough piece of equipment. It is
designed to withstand all sorts of abuse and keep on running. Its
fantastic that they can be relied on but it also leads to
procrastination and most times neglect about maintenance. Just
like a car, air conditioners need regular tune-ups to run
Without regular maintenance an air conditioner looses about
5% of it's original efficiency for each year of operation. In five
years you are paying 20 to 25 percent more on your utility bill
and wondering why it increased. This means that the 13 SEER
unit that you bought just a few years ago will be functioning
like a 10 SEER unit today! Do you know that you can recover
most of that lost efficiency through regular maintenance?
Studies show that with regular tune-ups a unit will maintain up
to 95% of its original efficiency. This means that the cost of an
annual tune-up is recovered very quickly in savings on your
monthly electric bill and reduced repair costs. A properly
serviced air conditioner will also do a better job of
dehumidifying your home and less humidity means less of a
chance of mold growing in your home.
If you choose not to check and maintain your own system you
might want to take advantage of some off-season bargains.
In the South many local air conditioning firms offer special prices
from January to March because it's out of season. Some even offer
annual service programs that insure that you will be reminded
of the need to service the unit at the beginning of the cooling
and heating seasons.
The number of things checked varies from one AC Company to
another depending on their credibility and the price they offer
for the tune up. This article is written so that you will be
familiar with what AC Company technicians should be doing
when they perform a tune up, but if you are inclined you can
perform most of the checks yourself. As a minimum the service
check by the AC Company should include cleaning the condensing unit
coils, checking the amp draw of the compressor, oiling the fan
motors, checking that belts are well adjusted (normally only in
commercial units), and checking the system operating
pressures and temperatures against the manufacturers
specifications. One of the most important items to check is the
coolant level (commonly know as Freon) in the air conditioner.
A system that is only 10% low on coolant will cost about 20%
more to operate!
If you are checking the system yourself you probably won't have all
the test equipment an AC Company does but you can check the
temperature difference (known as Delta T) to determine if the freon
or Puron charge is within normal pressures. We will teach you how to
do this later in this article.
There are some things in addition to yearly tune-ups that you
can do to help ensure a high level of comfort and proper system
operation. First, buy good filters and change them regularly (see
the article "All You Ever Wanted to Know About Filters" on this
website). Next, keep bushes and other materials away from the outside
unit of your air conditioner (see The Condenser). Also check the
blower and the Evaporator coil for blockage or build up (see The
article "Air Handler"). Another good idea is to avoid closing air
duct grills in unused rooms in your house. In almost all cases,
closing air duct grills is harmful to the operation of the overall
All equipment, even the most reliable, needs routine
maintenance. Complicated equipment like today's air
conditioners benefit in many ways from annual service. They
recover much of their lost efficiency, they are less likely to
suffer a major break down, they have a longer life span, they
increase your comfort, and they operate for less money.
What an Inspection of Your Cooling System Includes
1. Check wiring at furnace for loose connections to protect
electronic components from excess heat. Worn electrical
components can create a fire hazard or can cause your unit to
unexpectedly break down.
2. Tighten blower bolts and inspect fan to make sure your system is
blowing as much cold air as possible.
3. Inspect and clean or replace air filters to improve performance
and keep the air you breath clean. Clean air filters improve the
efficiency of your system and improve the quality of air
circulating through your home or place of business.
4. Inspect condensation drain to ensure the drain is clear. Clogged
condensation lines and drain lines can cause water (moisture
accumulated by your air conditioning system) to leak through your
ceilings or walls. Our cooling inspection also includes an algaecide
treatment to reduce the growth of algae and bacteria which can clog
your drain lines.
5. Delta T - Test temperature split between supplies and return
* Buy yourself a meat thermometer with the metal injector at
* Turn the thermostat on the AC System to COOL and turn the
temperature down to about 65 degrees.
* Insert the thermometer into the supply plenum as shown in
figure 6. Don't be afraid to put it right through the silver
lined insulation. If not accessible put it in the duct vent
nearest the air handler.
* Wait approximately 15 minutes.
* Read the temperature and write it down (it should be around
60 degrees). NOTE: if you put it in the nearest duct vent
subtract 2 degrees from the reading.
* Remove the thermometer and put it into the return plenum. If not accessible place it in the return grill.
duct vent inside the house.
* Wait 5 minutes.
* Write down the temperature.
* Subtract the Return temperature from the Supply
* It result should be around 16 degrees plus or minus 2
6. Check clearances around condenser to protect it from plants
7. Clean the condenser coil for better performance and a longer
CLEANING THE CONDENSER COIL requires only a garden hose and
about 5 minutes of your time. Cleaning it must be done from the
Fortunately the top of the condenser is open (through the fan grill).
First go to your Thermostat and turn the system to "Off". Then go to
your Electrical Breaker Box and turn the AC breaker off or, better
yet, there should be a Disconnect Box within sight next to the
condenser. It's usually a gray box mounted on the wall. Then take a
garden hose and spray into the fan grill from the top and pointing
toward the fins (you can see them inside through the grill). Go
around the condenser on all sides and make sure you point the hose
from top to bottom of the fins. Next rinse the fins from the
outside. Be careful because the fins are very easily bent. If you do
bend some fins or find some bent you can easily fix them. Your local
air conditioning distributor sells a tool call a "fin comb" that will
allow you to comb these fins back into nearly original condition. A
good trick is to point the hose at a 90-degree angle from the fins
(point it from the sides and not directly on them. THAT'S IT! The
coil is now cleaned. You can now turn on all electrical power and the
system from the Thermostat.
8. Check contactor for burnt or pitted points. Burned contactors
compromise the efficiency of a cooling system and can cause damage
to the compressor. It is much cheaper to have your contactors
replaced than it is to replace a compressor.
9. Tighten screws on condenser and check balance to help lower noise
10. Take note if there are any unusual sounde or excessive noise
11. Inspect breaker for condensing unit to avoid excessive heat and
early system failures.
12. Inspect evaporator coil for cleanliness and air flow
13. Inspect system for presence of Mold and bacterial growth
14. Visually inspect inside ducting for dirt and mold so you can keep
it out of your air supply.
15. Inspect ducting and connections for air loss.
16. Check for refrigerant temperatures and pressures for proper level
(AC Company check).
17. Measure compressor amp draws to ensure your system is using the
right amount of electricity AC Company check).
18. Inspect for loose electrical connections to help prevent failure
of circuit protectors (make sure all power is off).