My air conditioner is not working
93An air conditioner cools your home by pumping cold refrigerant through a series of coiled tubes, one inside your house called the evaporator, the other outside your house called condenser. The evaporator and the condenser are simply coils of copper tubing surrounded by aluminum cooling fins, much like an automotive radiator. A pump, known as the compressor circulates a heat transfer fluid, called refrigerant, through the tubes. When the refrigerant evaporates inside the evaporator it pulls heat from the air and cools the air. Ouside the house, the refrigerant releases its heat into the air via the condenser, reverts back to a liquid and is forced back into the house for more cooling.
Residential air conditioners come packaged a couple of different ways. The quick and dirty way to cool your home is with window-mounted room air conditioners. For more evenly distributed whole-house cooling, you're going to want to opt for a split or packaged central air system.
Room air conditioners are easy for almost anyone to install and operate plus they are inexpensive. Unfortunately, as the name implies, they are only good for cooling the room where they're located. They're available in 115 and 220-volt varieties.
Central air conditioners can circulate cool air throughout an entire house because they are plugged into a network of ducts that draw warm air and feed cool air. In a house equipped with a forced hot air heating system the installation of central air conditioning is relatively simple. In a house equipped with baseboard hot water or baseboard electric, the homeowner will have to go to the trouble and expense of installing the ducts.
Central air systems come in two varieties. Split system central air conditioning systems
utilize an outdoor metal cabinet which contains the condenser and compressor, and an indoor cabinet that contains the evaporator. In many split-system air conditioners, this indoor cabinet also contains a furnace or the indoor part of a heat pump. The air conditioner's evaporator coil is installed in the cabinet or main supply duct of this furnace or heat pump. If your home already has a furnace but no air conditioner, a split-system is the most economical central air conditioner to install.
In a packaged central air conditioner, the evaporator, condenser, and compressor are all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation. This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace. This combination of air conditioner and central heater eliminates the need for a separate furnace indoors.
If you are installing a new central air conditioning system, you may want to consider the size of the unit as well its efficiency -- both of which will have a direct impact on its price.
Air conditioners are rated by the number of BTUs they can remove in an hour. They might also be rated by the ton, which amounts to 12,000 BTUs per hour.
It's almost impossible to offer a general rule of thumb for determining air conditioner size because so many variables can come into play. For instance, the size of the unit will be based on how large your home is and how many windows it has, how much of your home is in the shade, the amount of insulation in your home's ceiling and walls and how much heat your major appliances generate.
There are formulas available to help homeowners determine this, but its probably best to let a reputable air conditioning contractor do the work for you. It is an important decision however, because too small an air conditioner will be overwhelmed and function poorly while too large an air conditioner will cost more and use more power to operate.
Equally important is the air conditioner's efficiency rating which should be posted on the air conditioners Energy Guide Label. More efficient air conditioners will cost more but you will reap benefits in reduced energy consumption over the life of the unit. It's not a bad idea to buy the most efficient unit you can afford.
Government standards require room air conditioners built after January 1, 1990, to have an energy efficiency rating of 8.0 or greater. Select a room air conditioner with an EER of at least 9.0 if you live in a mild climate. If you live in a hot climate, select one with an EER over 10.
Owners of older room air conditioner can realize energy savings by replacing their existing units with more modern ones. According to the Association of Home Appliance Manufacturers the average EER of room air conditioners rose 47 percent from 1972 to 1991. If you own a 1970s-vintage room air conditioner with an EER of 5 and you replace it with a new one with an EER of 10, you will cut your air conditioning energy costs in half.
National minimum standards for central air conditioners require an energy efficiency rating of 9.7 and 10.0, for single-package and split-systems, respectively. There are many units available with ratings as high as 17 however. According to the Association of Home Appliance Manufacturers, in 1979, the SEERs of central air conditioners ranged from 4.5 to 8.0. Replacing a 1970s-era central air conditioner with a SEER of 6 with a new unit having a SEER of 12 will cut your air conditioning costs in half.
Perhaps the single most important part of buying a new central air conditioning system is choosing the right contractor.
Don't be afraid to ask for references and be sure to get a written warranty. If you are replacing an existing system with a new one be sure to tell your contractor any problems you may have had with the old system so that he can address them during the new installation.
If you suspect your air conditioner needs a tune up, the Home Show is a great place to find a trained professional who can handle the job.
When interviewing prospective contractors be sure that they're capable of, checking the refrigerant, testing for leaks, capturing any refrigerant that may need to be evacuated from the system, measuring the system's flow, servicing the air conditioner's motor and checking its belts for tightness
An older air conditioning unit may provide years of trouble-free use, however, their operation can be hampered by a variety of conditions including:
Refrigerant leaks -- If your air conditioner is low on refrigerant, either it was undercharged at installation, or it leaks. If it leaks, simply adding refrigerant is not a solution. A trained technician should fix any leak, test the repair, and then charge the system with the correct amount of refrigerant. Remember that the performance and efficiency of your air conditioner is greatest when the refrigerant charge exactly matches the manufacturer's specification, and is neither undercharged nor overcharged.
Inadequate maintenance -- If you allow filters and air conditioning coils to become dirty, the air conditioner will not work properly, and the compressor or fans are likely to fail prematurely.
Electric control failure -- The compressor and fan controls can wear out, especially when the air conditioner turns on and off frequently, as is common when a system is oversized. Because corrosion of wire and terminals is also a problem in many systems, electrical connections and contacts should be checked during a professional service call.
There isn't all that much that a homeowner can do to keep an air conditioning system healthy and happy, but there are a few basic maintenance checks that can be performed.
Perhaps the most important and simple maintenance measure that will ensure the efficiency of your air conditioner is to routinely replace or clean its filters. Clogged, dirty filters block normal air flow and reduce a system's efficiency significantly. With normal air flow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity. Filters are located somewhere along the return duct's length. Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself.
Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.
The air conditioner's evaporator coil and condenser coil collect dirt over their months and years of service. A clean filter prevents the evaporator coil from soiling quickly. In time, however, the evaporator coil will still collect dirt. This dirt reduces air flow and insulates the coil which reduces its ability to absorb heat. Therefore, your evaporator coil should be checked every year and cleaned as necessary.
Outdoor condenser coils can also become very dirty if the outdoor environment is dusty or if there is foliage nearby. You can easily see the condenser coil and notice if dirt is collecting on its fins.
You should minimize dirt and debris near the condenser unit. Your dryer vents, falling leaves, and lawn mower are all potential sources of dirt and debris. Cleaning the area around the coil, removing any debris, and trimming foliage back at least 2 feet (0.6 meters) allow for adequate air flow around the condenser.
The aluminum fins on evaporator and condenser coils are easily bent and can block air flow through the coil. Air conditioning wholesalers sell a tool called a "fin comb" that will comb these fins back into nearly original condition.
An enormous waste of energy occurs when cooled air escapes from supply ducts or when hot attic air leaks into return ducts. Recent studies indicate that 10 percent to 30 percent of the conditioned air in an average central air conditioning system escapes from the ducts.
For central air conditioning to be efficient, ducts must be airtight. Hiring a competent professional service technician to detect and correct duct leaks is a good investment, since leaky ducts may be difficult to find without experience and test equipment. Ducts must be sealed with duct "mastic." The old standby of duct tape is ineffective for sealing ducts.
Obstructions can impair the efficiency of a duct system almost as much as leaks. You should be careful not to obstruct the flow of air from supply or return registers with furniture, drapes, or tightly fitted interior doors. Dirty filters and clogged evaporator coils can also be major obstructions to air flow.
The large temperature difference between attics and ducts makes heat conduction through ducts almost as big a problem as air leakage and obstructions. Ducts in attics should be insulated heavily in addition to being made airtight.
Finally, the overall efficiency of any air conditioner depends largely on its operator. Installing a programmable thermostat will keep you from forgetting to turn the AC down when you aren't home, saving energy as well as wear and tear on the machine.
Simply drawing the blinds to prevent sunlight from warming your house will help make your air conditioner last longer and draw less power too.
-- Information for this article was provided Federal Department of Energy
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How to Troubleshoot a Central Air Conditioning System
Central air conditioners have two separate components: the condenser and the evaporator. The condenser unit is usually located outside the house on a concrete slab. The evaporator coil is mounted in the plenum or main duct junction above the furnace.Most central air conditioners are connected to a home's forced-air distribution system. Thus, the same motor, blower, and ductwork used for heating are used to distribute cool air from the air conditioning system. When a central air conditioner is operating, hot air inside the house flows to the furnace through the return-air duct. The hot air is moved by the blower across the cooled evaporator coil in the plenum and is then delivered through ducts to cool the house. When the air conditioner works but the house doesn't cool, the problem is probably in the distribution system.
Both the evaporator and the condenser are sealed. Therefore, a professional service person should be called for almost any maintenance other than routine cleaning. Central air conditioners should be professionally inspected and adjusted before the beginning of every cooling season. However, don't let your maintenance end with this annual checkup. While there aren't many repairs you can make yourself, there are specific maintenance procedures you can follow to keep your system operating at peak efficiency. Caution: Before doing any work on an air conditioning system, make sure the power to the system, both to the condenser and to the evaporator assembly, is turned off.Cleaning the EvaporatorThe evaporator for the central air system is located directly above the furnace in the plenum. The evaporator may not be accessible, but if it is, you should clean it once a year. If the plenum has foil-wrapped insulation at its front, you can clean the evaporator; if the plenum is a sealed sheet metal box, do not attempt to open it. Here's how to clean an accessible evaporator:Step 1: Remove foil-wrapped insulation at front of plenum; it's probably taped in place. Remove tape carefully, because you'll have to replace it later. Behind insulation is access plate, which is held in place by several screws. Remove screws and lift off plate.
What You'll NeedYou'll want to have these tools on hand to clean the evaporator: Screwdriver Stiff brush Large hand mirror Household bleach Wire
Step 2: Clean entire underside of evaporator unit with stiff brush. A large hand mirror can help you see what you're doing. If you can't reach all the way back to clean entire area, slide evaporator out a little. Evaporator can be slid out even if it has rigid pipes connected to it, but be careful not to bend pipes.Step 3: Clean tray below evaporator unit. This tray carries condensation away from evaporator. Pour 1 tablespoon of household bleach into weep hole in tray to prevent fungus growth. In extremely humid weather, check condensate drain and pan every other day. If there's much moisture in pan, weep hole from pan to drain line may be clogged. Open weep hole with piece of wire.Step 4: Put unit back into place, reinstall plate, and tape insulation back over it.Step 5: Turn back on air conditioner, and check for air leaks. Seal any leaks with duct tape.Maintaining the CondenserIn most air-conditioning systems, the condenser unit is located outside the house and is prone to accumulate dirt and debris from trees, lawn mowing, and airborne dust. The condenser has a fan that moves air across the condenser coil. You must clean the coil on the intake side, so, before you turn off the power to the air conditioner, check to see which direction the air moves across the coils. Here's how to clean the condenser:Step 1: Cut down any grass, weeds, or vines that have grown around condenser unit; they could be obstructing airflow.
What You'll NeedYou'll want to have these tools on hand to clean the condenser:Grass shears or pruners Spray bottle of coil cleaner Soft brush Fin comb Carpenter's level Pry bar or piece of 2-by-4 Gravel or rocks
Step 2: Clean condenser with commercial coil cleaner, available at refrigerator supply stores. Instructions for use are included. Flush coil clean (do not use hose); let dry.Step 3: Clean fins with soft brush to remove accumulated dirt. You may have to remove protective grille to reach them. Do not clean fins with garden hose, as water could turn dirt into mud and compact it between fins. Clean fins very carefully: They're made of light-gauge aluminum and are easily damaged. If fins are bent, straighten them with fin comb, sold at most appliance parts stores. A fin comb is designed to slide into spaces between fins. Use it carefully to avoid damaging fins.Step 4: Check concrete pad on which condenser rests to make sure it's level. Set carpenters' level front to back and side to side on top of unit. If pad has settled, lift pad with pry bar or piece of 2-by-4, then force gravel or rocks under concrete to level it.During the fall and winter, outside condenser units should be protected from the elements to prevent leaf blockage and ice damage. Cover the condenser unit with a commercial condenser cover made to fit the shape of the unit or use heavy plastic sheeting secured with sturdy cord.Handling the RefrigerantThe coolant used in most air conditioning systems is a refrigerant called Freon. If the system does not contain the proper amount of Freon, little or no cooling will take place. If you suspect a Freon problem, call a professional service person to recharge the system. Caution: Do not try to charge your system's refrigerant lines.
System Care GuideProblems with your central air system can cause your brain to short-circuit. Never fear, click here for a complete troubleshooting guide.
Here's how you can repair the system's coolant lines. Examine the lines running from the condenser outside the evaporator inside the house. If the insulation is damaged or worn, it will cut down on the cooling efficiency of the unit and, therefore, should be replaced. Replace damaged or worn coolant line insulation with new insulation of the same type as soon as possible. Follow manufacturer's instructions for installation.Many homes or apartments use window-unit air conditioners, so it's also important to know how to maintain or service these smaller units. Learn how to head off problems and keep these units running smoothly in the next section.
Room air conditioners, also called window units, work the same way central air conditioners do. They are smaller than central systems and often more expensive to operate. Depending on its size, a room unit may cool only the room in which it's located, or it may be able to cool adjoining rooms as well.Sandwiched between the coils are a compressor, two fans, a motor, and thermostat controls. Dirt is the biggest enemy of window air conditioners; it can lower the efficiency of the evaporator coil, block the operation of the fan that blows out the cool air, clog filters, and block drain ports.The coils, the compressor, and the motor of a room air conditioner are sealed components, so any repairs to them should be left to a professional service person. However, you can make minor repairs, and regular maintenance will keep your unit running well. When extensive repairs are needed, you can also save the cost of a service call by removing the air conditioner from its mounting and taking it to the repair shop.During the winter, room air conditioners should be protected from the elements. Either remove the unit from its mounting and store it or cover the outside portion of the unit with a commercial room air conditioner cover or with heavy plastic sheeting, held in place with duct tape.Caution: Before doing any work on a room air conditioner, make sure it's unplugged. Room air conditioners have either one or two capacitors, located behind the control panel and near the fan. Capacitors store electricity, even when the power to the unit is turned off. Before you do any work on an air conditioner, unplug it and discharge the capaci
I am having trouble with my ac. It is a split unit . I have cleaned it but it still leaks. I have been told it could be unlevel. How do I level the inside unit?
i turned on my central AC
i turned on my central AC & forgot to remove the wooden board I had on top as a cover after running 5 min. it stopped now i cant get it to work?
Good info on airconditioners. If I ever I'd have to buy a new one I'd certainly go back to your hub and review the info there. I'm into home improvement myself, which is why I found your hub.
what is the difference between COP&EER of an AC
I had two units that settled and no longer drained properly. They leaned away from the condensation line. I used some PVC under the units to re-level and the condensation drained properly again.
Thank you for sharing your knowledge about air conditioners. I will clean my filter more often. God Bless You.
you can buy furnace filters and refill media too. check more on http://airsponge.com All types of air filters for air conditioning, filter for ac, carbon filters, air filter best, ac filter are in stock.
Reading your article is the first step making sure we don't spend more money than we need to spend cooling our home. Thank you for the information
www.myairnow.com is a local AC repair company in Tampa FL
http://www.myairnow.com Tampa fl a/c repair services
The coils of air condition is dirty. Inside unit are a magnet to dust and dirt. Even if you are diligent in replacing your air filters every 3 months as you should, it is inevitable that eventually your coil system will need cleaning.
miloskorac Hub Author 4 years ago
Steps1Step OneRemove the front grill. Pry it off with a putty knife if it's held by clips, or use a screwdriver if it is screwed in place. 2Step TwoUnplug the air conditioner, slide it out of the window cabinet and set it on a sturdy table. You may need a helper to move the air conditioner if it's heavy. 3Step ThreeLocate the mesh filter. It covers the radiator-like fins on the machine's evaporator coils. 4Step FourRemove the filter, and wash it and the grill in a mixture of warm, soapy water and bleach--this will remove any mold. Shake out the excess water and set the filter and grill in your dish drain to dry. 5Step FiveVacuum the evaporator coils thoroughly, using a vacuum with brush attachment. Remove any stubborn dirt with a plastic scrub brush. 6Step SixInspect the fins on the coils. If any fins are bent or flattened, buy a fin comb from an appliance store and run the comb up or down the fins to straighten them. 7Step SevenTurn the air conditioner around so the back is facing you. You will see a second set of coils--the machine's condenser coils. 8Step EightVacuum these coils thoroughly, using the vacuum and brush attachment. Remove any stubborn dirt with a plastic scrub brush. 9Step NineInspect the fins on the condenser coils, and if any are bent, use the fin comb to straighten them. 10Step TenRemove any dirt or lint from inside the unit, using the vacuum and crevice attachment. Make sure you clean the fan blades, too, using the vacuum and brush attachment. 11Step Eleven Put the air conditioner back into the window cabinet. 12Step Twelve Reinstall the filter and front grill, and plug in the machine.