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Air conditioning FAQ

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1-What is the life expectancy of an air conditioner?
2. Which is the best air conditioning system manufactured today?
3- Is it better to have the air conditioning system be a little larger than needed, so it does not have to work so hard?
4. What causes a water leak?
5-Why does dirt accumulate on my coils when I change my filters regularly?
6- How can I prevent water leaks from happening?
7-What effects do dirty components have on my system?
8-How often should my system be cleaned?
9-What is a contactor & what does it do?
10-Why should a contactor be replaced even though it is working?
11-What is a power surge protector (PSP) ?
12-. What is a time delay switch ?
13- How do I know my system has a refrigerant or Freon leak?
14- How do I know my motor is defective?
15-Is compressor replacement a good economic decision?
16- Will duct sanitizing help control allergies, asthma & congestion?
17- Where can I find biological pollutants in my home?
18- What causes duct work to sweat?
19-. Why is an evaporator coil wash so expensive ?
20- I was told my system has non-condensables in it ?
21- What effects do non-condensibles have on my system?
22-What are the advantages of a preventive maintenance policy (PMP)?
23- How can I lower my electric bill with my existing air conditioner ?
24-Should You Have the Air Ducts in Your Home Cleaned?

1-What is the life expectancy of an air conditioner?

With proper maintenance, we have seen air conditioning systems last over 20 years!

In Costa Rica, the average is 8-10 years.

2. Which is the best air conditioning system manufactured today?

All air conditioners contain relatively the same components regardless of brand name. They all have a compressor, coils, motors, capacitors, and controls.
There are many different brand names, some you have probably never heard of.
In our opinion, the air conditioner is only as good as the manufacturer's warranty. Choose the air conditioner that gives you the longest and best warranty.
The most important variable is the contractor you choose for the installation.
The best air conditioner is the one that gives you the least trouble.

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3- Is it better to have the air conditioning system be a little larger than needed, so it does not have to work so hard?

Absolutely not. As a matter of fact it is better to be a little undersized rather than oversized.

Why?

If your air conditioning system is larger than required, the system lowers the temperature in the house faster. In this case, the air conditioner does not run long enough to remove the moisture in the air conditioned space.
Although the temperature will be cool, there will be too much humidity in the air and you will not feel cool.
The only time your air conditioner is lowering the humidity is when the compressor is running. When the temperature outside is higher your compressor should be running almost continuously.

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4. What causes a water leak?

Dirt or foreign matter causes water to drip off the coil instead of draining to the bottom.
Ice on coils restricts the air flow.
The unit is low on the refrigerant Freon, causing icing and rapid meltdown.
Algae can grow in this cool damp environment and can block drain pan parts.

Helpful hints for a water leak?

Make sure air filter is clean.
Connect a vacuum cleaner hose at the end of drain line outside.
Disconnect drain line (PVC) from unit and flush out with water.
Pour several ounces of bleach in drain pan or drain line.

Even though you keep clean filters in the unit, dirt will accumulate on the coil and in the drain circuit.
This is because many filters catch only about 8-12% of the particles in the air. These filters let most fine particulate matter pass right through them.
The evaporator coil is wet during the cooling operation and so it collects a lot of the fine particles on its surface or in the drain pan.
In time, the accumulation of particles will cause water to drip onto the floor.

Flush your drain line periodically.
Consider a higher efficiency air filter.
Have your system inspected and cleaned regularly.

Dirt blocks heat transfer which causes or contributes to all or some of the following: Compressor fan motors run hot, lubrication breaks down (life is shortened).
Cooling capacity is reduced.
Humidity removal is reduced.
Operating cost increases.
Compressor valves can be damaged due to freon & floodback.
Coil can ice over, stopping all cooling & possibly causing damage due to a water leak.
Air conditioning systems usually do not ware out. They burn out from over heating.

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8-How often should my system be cleaned?

It depends on the system's location, running time, and the type of the system.
Even if you conscientiously change your filters every month, your system should be checked once a year.
It is always better to be safe then sorry.

A contactor is a device used to bring high voltage to your compressor to start and run it.
The contactor points snap together through magnetic action each time your unit starts.
At startup, your compressor is pulling maximum amperage, several times the regular running current.
A small amount of electric arcing occurs each time the contactor points close.
This gradually causes the contact points to become burned and pitted.

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10- Why should a contactor be replaced even though it is working?

If your technician finds burned and /or pitted contact points, he will recommend contactor replacement because: The amount of electric arcing will be greater when they are pitted.
The full surface of the points cannot make contact.
Items 1 and 2 can cause the compressor to draw more current than it is rated for which may cause overheating.
The points can became so hot that they fuse and the unit runs constantly.
Fused points with the indoor unit not running can damage the compressor.
Replacing burned or pitted contactors will save a service call and possibly more expense later.

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11- What is a power surge protector (PSP)?

A power surge protector is a device that is wired into your air conditioning system to protect against power fluctuations that happens in a fraction of a second and can cause serious damage to your compressor, motors, controls, etc.
Lightening strikes and electric power spikes from the local utility company can enter your home through the electrical wiring and harm electrical components that are connected to them.
The power surge protector absorbs the power surges in its own circuitry and prevents the surge from damaging your equipment.

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12-. What is a time delay switch?

A time delay switch causes a delay before a compressor starts.
The delay allows the compressor to start with no load on it.

Why is this important?

When electric power is temporarily lost, or a thermostat is turned on-off-on rapidly while the compressor is in operation, the compressor tries to re-start against unequal Freon pressure. This applies enormous strain to the compressor motor windings.

This is a major contributor to compressor failure. Normally, the system requires 3-5 minutes in the off cycle for the Freon pressure to equalize.
The time delay switch protects the compressor and its motor windings.
By using a time delay switch, you will extend the life of the compressor.

Remember compressors don't wear out they burn out.

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13- How do I know my system has a refrigerant or Freon leak?

If your system is low on Freon, it probably has a leak.

What causes Freon leaks? Unit vibration over a period of time.
Abuse or damage from outside sources.
Copper/aluminum stress fractures due to age and/or vibration.
Service valves become worn over time.
How are Freon leaks located? Visual inspection for traces of oil leaking with the Freon.
Using a high viscosity bubble leak detector solution on joints and connections.
A halide (flame color change) leak detection tool.
Electronic leak detector instruments.
An injection of fluorescent solution.
Low operating suction pressure.

14- How do I know my motor is defective?

Your technician has performed one or more of the following diagnostic tests: A resistance measurement was made on the motor windings with a mega ohmmeter.
Has verified shaft seizure & locked rotor amperage draw.
Verified that any run capacitor is not defective.

How does a motor becomes defective?

Worn components due to age (average life span 5 to 10 years).
Seized fan blade or blower wheel no longer cools, causing motor burnout.
Overheating due to burnouts power surges, lightning, etc.
Dirty motor and/or coils cause low airflow and overheating.
Lack of proper maintenance, especially regular lubrication.

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15-Is compressor replacement a good economic decision?

It depends.
If the compressor is under warranty, It makes sense to replace the compressor.

If the system is less than six years old: It makes sense to replace the compressor when the rest of the system is in good working condition.

If the system more than six years old and the compressor is no longer under warranty: Consider replacement the system/unit because:
1. Today's new systems are more efficient and will save money on operating costs.
2. The new system will come with a five-ten year compressor warranty.
3. If you replace the compressor, the new compressor will be part of an old system/unit with older parts that are out of warranty.
4. The replacement compressor will have only a one year warranty.
5. The difference may be less than you think with operating savings factored in.

Yes. Duct sanitizing together with air purification systems, such as UV lights and HEPA filters, can provide an effective means of alleviating allergy symptoms in the home.
Allergic reactions may be the most common health problem associated with indoor air quality in homes, with the exception of airborne viruses and bacteria.
Allergies are often related to: Animal dander from pets, especially cats and dogs
Dust mites which are microscopic organisms that live in household dust.
Pollen from seasonal outdoor plants.

Allergic reactions can range from mildly uncomfortable to life-threatening, such as a severe asthma attack. Common symptoms are watery eyes, runny nose, sneezing, nasal congestion, itching, coughing, wheezing, difficulty breathing, headache and fatigue.

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17- Where can I find biological pollutants in my home?

Dirty air conditioning ducts
Dirty Humidifiers/Dehumidifiers
Bathroom without vents or windows
Dirty Refrigerator drip pans
Carpets
Dogs and Cats
Closet on outside wall
Bedding
Kitchen without vents or windows
Laundry room with un-vented dryer
Water damage areas-damp
Unventilated Attic

Sweating duct work is an environmental problem caused by low attic temperature and humid weather conditions. The duct work sweats when its surface temperature drops below the dew point temperature in the attic.

Example 1. Poorly sealed ducts and ducts with holes cause condensation. When ducts are not properly sealed, cool air leaks into the attic environment. This causes the duct surface temperature to drop below the dew point, thereby causing the ducts to sweat.

Example 2. Forced attic ventilation can cause problems. When the attic is ventilated, it draws outside air in and causes moisture levels and the dew point to rise. The duct work sweats because its surface temperature drops below the dew point.

Since we change the weather, let's look at ways to change the conditions in the attic.

Solutions:

1. Don't add an exhaust fan. It creates a constant supply of humid air entering the attic.

2. Increase the ambient temperature. Block the attic vents with plastic sheeting and install flood lights controlled by a thermostat so that the attic temperature can be maintained at 90 degrees Fahrenheit. The dew point temperature will be reduced. The sweating will be reduced or eliminated because the duct work's surface temperature will be maintained above the dew point.

3. Lower the dew point. Block all attic vents and install a dehumidifier. The dew point drops as the excess humidity is removed from the environment. Sweating is eliminated when the dew point temperature is lower than the surface temperature of the duct work.

Conclusion:

Sweating duct work is not an equipment or installation problem. It is an environmental problem that is influenced by the weather. If you can change the environment around the ducts, the problem can be eliminated.

19-. Why is an evaporator coil wash so expensive?

For a split system:

1-All the refrigerant Freon must be removed from the refrigerant lines and the coil.

2-The coil has to be removed from the air handler.

3-First the coil given a chemical wash and then it is pressure washed several times.

4-The coil is placed back into the air handler and the connections are welded again.

5-The air conditioning system is then evacuated, also known as pumped down.

6-The refrigerant, Freon gas, is added and brought back to its proper level.

7-Depending on the size of the system, the charges are anywhere from $275 - $400.

20- I was told my system has non-condensables in it?

Air and water are the best known non-condensables in a refrigeration system.
Air and water usually enter a system through poor service practices and/or leaks.
If a technician forgets to purge hoses, this can let air and water vapor into a system.

21- What effects do non-condensibles have on my system?

They cause compressor fan motors to run hot. The lubrication breaks down and life is shortened.
Cooling capacity is reduced.
Operating cost increases.
Compressor valves can be damaged.
The coil can ice over, preventing cooling and causing damage due to water leaks.
Air conditioning systems usually do not wear out.
They burn out from over heating.

22-What are the advantages of a preventive maintenance policy (PMP) ?

A regular maintenance program can add years of trouble free cooling comfort to the life of your system. Most systems fail due to lack of maintenance. Motors must be lubricated once a year. Drain pans should be flushed and cleaned often. Electrical connections should be tightened. One benefit of annual maintenance is that failing parts can be spotted and replaced before damage to the system occurs. Major costly repairs can be avoided by replacing contactors and other simple electrical components before they fail.

Advantages :

Insures cooling comfort.
Equipment has longer life.
Prevents costly repairs.
Avoid messy water leak damages.
Lower electrical costs Compressor failures.
Loose wires and shorted connections.
Rattles, noises and other nuisance calls.

23- How can I lower my electric bill with my existing air conditioner?

Clean the coils and blower wheels. Dirty coils inhibit heat transfer.
Cleaning the coil can restore the original efficiency.
Charge the system to the proper refrigerant Freon level.
Size the refrigerant lines properly for good Freon flow.
Repair leaking ductwork.
Balance the system air flow.
Size the duct work properly for the system and building size.
Seal the exterior doors and windows to prevent air leakage.
Insulate the attic space to a minimum of R-19. The higher the better.
Shut off all exhaust fans when not in use.

Look EPA'S answer!

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