HVAC Systems



             


Friday, January 4, 2008

How to Get your Air Conditioner ready for Next years Heat

Jack Frost is nipping at our nose and Santa Clause has just left. The eastern seaboard has just received their third blizzard for a total of over 125 cm (56 inches) of snow in one week. So, who in their right mind would be thinking about window air conditioners at this time of year?

Call me crazy, but I am.

It is a good time of year to start this project. Firstly, it keeps ones mind sharp for the coming spring. Plus, it allows you to try out those new tools you got for Christmas. Mainly though, it is a good winter project because by the time spring arrives you will be too busy to think about this job.

Very little is required to clean a window air conditioner, except lots of patience. If patience is something you lack then it is a job you should turn over to the local appliance serviceman.

Tools ----------------------
Tin can or container (old muffin tin works well also)
Vacuum cleaner
Long handled brush (an old toilet brush works well)
Oil can
Rags
De-greaser or spray detergent
Selection of screwdrivers (Philips, Flat bladed, 1/4" socket head)
Fin tool (optional)
New filter (if disposable type)

Lets get started -----------

1. Start by removing the filter from the front grille. If it is a disposable type simply replace it with a new one. Other types are made in a plastic frame and can be cleaned and reused. To clean a reusable type lay it flat in the sink and sprinkle surface with laundry detergent. Then cover with about one inch of hot water. Just enough so the filter is submerged. Soak for 15 minutes. Remove from water and rinse with warm water. Hang up to dry while proceeding to next step.

2. Next, remove the front grille from the main body of the air conditioner. They usually pivot on 2 spring clips at the bottom. It is usually removed by pulling the grille gently forward while pushing it down at the same time. If there is resistance then look for hidden screws. Look near the top edge of the grille or behind the control knob door. Once removed place the grille aside until later.
3. Carefully remove metal cover of air conditioner to expose inner workings. Once all the screws are removed lift the cover straight up. Do not let it hit the other parts as it can have sharp edges. This is where the old can comes in handy (ice cube container or muffin tin works well also). Use it to keep track of all the screws you will be removing. An air conditioner will often use a number of different types and sizes of screws. Segregate them from each other or confusion will result when we start reassembly.

4. Check the fan motor for any oil holes or oil plugs. If the motor has oil plugs they are usually rubber. Use caution when removing because the rubber may have become brittle. Often they will break off in the oil holes resulting in a blockage. If this occurs try to remove the broken plug by using a pin of the tip of a small screwdriver.
Once the fan motor oil holes are exposed add a few drops of oil to each end of the motor body. Use a general purpose (3in1) oil or clean motor oil. A #30 oil is sufficient.
The natural tendency is to over-oil. Too much lubrication is as bad as not enough. Therefore only 3 or 4 drops on both ends of the motor body is sufficient. Add the oil slowly, pausing a few seconds between each drop. If you add it too quickly over-lubrication will result.

5. Use the brush to remove surface dust and dirt from the evaporator (front fins). Use only an up and down motion. Do not go side to side or allow the fins to be bent over. The fins are very soft aluminum and can be damaged easily.
Once surface dirt is removed, spray with de-greaser or cleaner. There is a good product on the market called HVAC cleaner. As the name implies it is meant for Heating, Ventilation, and Air Conditioner coil cleaning. If this is not available the Fantastic Spray cleaner used in kitchens and bathrooms works quite well.
Let stand about 15 minutes or as per instructions on de-greaser can. This will allow cleaner to loosen any hidden dirt. Remove dirt and excess cleaner by slowly pouring warm water into fins. Do not allow the water to enter any electrical connections or components that may be near the coil. As an added precaution cover the motor with one of the cloth rags. to protect it from the water.
Do not use any form of high pressure air or water because this can drive dirt farther into fins. Also, use extreme caution as these coils are filled with high pressure refrigerant.

6. Straighten any bent fins. Use a fin comb if available. If no fin comb then use something soft such as a Popsicle stick. Straightening the fins will increase the efficiency of the air flow through the coils. This adds to the overall cooling effect produced by the air conditioner.

7. Repeat steps 5 and 6 for the condenser (rear fins) coil. A plastic cowling usually surrounds the condenser fins. If so, check the top edge to see if it will lift or open. If it opens this will allow easier access to the condenser fins. Again use caution because the condenser coil is also filled with high pressure refrigerant.

8. Wipe any dirt buildup from both fan blades using a soft rag. Do not bend blades. This would cause a vibration that would harm the motor.

9. Vacuum all surfaces including front and back of grille assembly. Do not forget to vacuum underside of metal air conditioner cover. If the cover contains air holes clean them thoroughly. If necessary use a damp rag.

10. Drain any water left in the base and allow it to dry for few hours.

When completely dry plug in air conditioner and test operation. If everything appears okay unplug and reassemble.

Once reassembly is complete, retest operation to ensure replacing the cover has not affected anything. Adding the cover will tend to twist the frame and can cause interior parts to move out of alignment. This can cause the fan to become noisy. To correct for this problem remove the cover and realign to the main body of the air conditioner. Reinstall the cover and test for noises every time 2 or 3 additional screws are added to the cover.

Finally, cover air conditioner with plastic wrap or an old blanket. Store in a warm dry area. Raise it from floor slightly by placing onto a couple of pieces of wood. This will protect the floor from the metal edges of the air conditioner, and also protect the air conditioner from moisture.

Youre Finished ------------

Repeat this simple procedure every year. If you do, the machine will be ready for many more years of dependable service.

Addendum -------------------

The filter inside the front grille should be removed and cleaned (as in step 1) every month throughout the cooling season. If you are a smoker it should be cleaned every week.

Although the above procedure is for a window air conditioner, the same basic method is used to clean a central air system. Due to additional dangers inherent in the central air conditioner systems, they should be cleaned only by a professional service company.


Jack Frost is nipping at our nose and Santa Clause has just left. The eastern seaboard has just received their third blizzard for a total of over 125 cm (56 inches) of snow in one week. So, who in their right mind would be thinking about window air conditioners at this time of year?

Call me crazy, but I am.

It is a good time of year to start this project. Firstly, it keeps ones mind sharp for the coming spring. Plus, it allows you to try out those new tools you got for Christmas. Mainly though, it is a good winter project because by the time spring arrives you will be too busy to think about this job.

Very little is required to clean a window air conditioner, except lots of patience. If patience is something you lack then it is a job you should turn over to the local appliance serviceman.

Tools ----------------------
Tin can or container (old muffin tin works well also)
Vacuum cleaner
Long handled brush (an old toilet brush works well)
Oil can
Rags
De-greaser or spray detergent
Selection of screwdrivers (Philips, Flat bladed, 1/4" socket head)
Fin tool (optional)
New filter (if disposable type)

Lets get started -----------

1. Start by removing the filter from the front grille. If it is a disposable type simply replace it with a new one. Other types are made in a plastic frame and can be cleaned and reused. To clean a reusable type lay it flat in the sink and sprinkle surface with laundry detergent. Then cover with about one inch of hot water. Just enough so the filter is submerged. Soak for 15 minutes. Remove from water and rinse with warm water. Hang up to dry while proceeding to next step.

2. Next, remove the front grille from the main body of the air conditioner. They usually pivot on 2 spring clips at the bottom. It is usually removed by pulling the grille gently forward while pushing it down at the same time. If there is resistance then look for hidden screws. Look near the top edge of the grille or behind the control knob door. Once removed place the grille aside until later.
3. Carefully remove metal cover of air conditioner to expose inner workings. Once all the screws are removed lift the cover straight up. Do not let it hit the other parts as it can have sharp edges. This is where the old can comes in handy (ice cube container or muffin tin works well also). Use it to keep track of all the screws you will be removing. An air conditioner will often use a number of different types and sizes of screws. Segregate them from each other or confusion will result when we start reassembly.

4. Check the fan motor for any oil holes or oil plugs. If the motor has oil plugs they are usually rubber. Use caution when removing because the rubber may have become brittle. Often they will break off in the oil holes resulting in a blockage. If this occurs try to remove the broken plug by using a pin of the tip of a small screwdriver.
Once the fan motor oil holes are exposed add a few drops of oil to each end of the motor body. Use a general purpose (3in1) oil or clean motor oil. A #30 oil is sufficient.
The natural tendency is to over-oil. Too much lubrication is as bad as not enough. Therefore only 3 or 4 drops on both ends of the motor body is sufficient. Add the oil slowly, pausing a few seconds between each drop. If you add it too quickly over-lubrication will result.

5. Use the brush to remove surface dust and dirt from the evaporator (front fins). Use only an up and down motion. Do not go side to side or allow the fins to be bent over. The fins are very soft aluminum and can be damaged easily.
Once surface dirt is removed, spray with de-greaser or cleaner. There is a good product on the market called HVAC cleaner. As the name implies it is meant for Heating, Ventilation, and Air Conditioner coil cleaning. If this is not available the Fantastic Spray cleaner used in kitchens and bathrooms works quite well.
Let stand about 15 minutes or as per instructions on de-greaser can. This will allow cleaner to loosen any hidden dirt. Remove dirt and excess cleaner by slowly pouring warm water into fins. Do not allow the water to enter any electrical connections or components that may be near the coil. As an added precaution cover the motor with one of the cloth rags. to protect it from the water.
Do not use any form of high pressure air or water because this can drive dirt farther into fins. Also, use extreme caution as these coils are filled with high pressure refrigerant.

6. Straighten any bent fins. Use a fin comb if available. If no fin comb then use something soft such as a Popsicle stick. Straightening the fins will increase the efficiency of the air flow through the coils. This adds to the overall cooling effect produced by the air conditioner.

7. Repeat steps 5 and 6 for the condenser (rear fins) coil. A plastic cowling usually surrounds the condenser fins. If so, check the top edge to see if it will lift or open. If it opens this will allow easier access to the condenser fins. Again use caution because the condenser coil is also filled with high pressure refrigerant.

8. Wipe any dirt buildup from both fan blades using a soft rag. Do not bend blades. This would cause a vibration that would harm the motor.

9. Vacuum all surfaces including front and back of grille assembly. Do not forget to vacuum underside of metal air conditioner cover. If the cover contains air holes clean them thoroughly. If necessary use a damp rag.

10. Drain any water left in the base and allow it to dry for few hours.

When completely dry plug in air conditioner and test operation. If everything appears okay unplug and reassemble.

Once reassembly is complete, retest operation to ensure replacing the cover has not affected anything. Adding the cover will tend to twist the frame and can cause interior parts to move out of alignment. This can cause the fan to become noisy. To correct for this problem remove the cover and realign to the main body of the air conditioner. Reinstall the cover and test for noises every time 2 or 3 additional screws are added to the cover.

Finally, cover air conditioner with plastic wrap or an old blanket. Store in a warm dry area. Raise it from floor slightly by placing onto a couple of pieces of wood. This will protect the floor from the metal edges of the air conditioner, and also protect the air conditioner from moisture.

Youre Finished ------------

Repeat this simple procedure every year. If you do, the machine will be ready for many more years of dependable service.

Addendum -------------------

The filter inside the front grille should be removed and cleaned (as in step 1) every month throughout the cooling season. If you are a smoker it should be cleaned every week.

Although the above procedure is for a window air conditioner, the same basic method is used to clean a central air system. Due to additional dangers inherent in the central air conditioner systems, they should be cleaned only by a professional service company.
Donald Grummett is an appliance service manager in Ottawa, Canada. In the trade over 30 years as both a technician, business owner, and technical trainer. For more information about appliances including FAQ, Stain guide, Recycling, and Newsletter visit http://www.mgservices.ca

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Wednesday, November 28, 2007

A Cars HVAC System

Not only do we depend on our cars to get us where we want to go, we also depend on them to get us there without discomfort. We expect the heater to keep us warm when it's cold outside, and the air conditioning system to keep us cool when it's hot.
We get heat from the heater core, sort of a secondary radiator, which is part of the car's cooling system. We get air conditioning from the car's elaborate air conditioning system.
Despite its relatively small size, the cooling system has to deal with an enormous amount of heat to protect the engine from friction and the heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to the useful purpose of keeping us warm.
Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), the outside air entering your car. It also has the task of keeping the air at the temperature you select. These are all big jobs. How do our cars keep our "riding environment" the way we like it?
Most people think the air conditioning system's job is to add "cold" air to the interior of the car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of the air conditioning system is really to remove the heat that makes us uncomfortable, and returns the air to the car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air).
A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, the way we call copy machines "Xerox" machines). The compressor moves the Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to the evaporator. The evaporator is right in front of a fan that pulls the hot, humid air out of the car's interior. The refrigerant makes the hot air's moisture condense into drops of water, removing the heat from the air. Once the water is removed, the "cool" air is sent back into the car's interior. Aaaaaah! Much better. Newer cars have R-134 as the refrigerant, but work in the same way as R-12.
Sometimes we worry when we catch our car making a water puddle on the ground, but are relieved to discover that it's only water dripping from the air conditioning system's condenser (no color, no smell, and it dries!).
Note: Refrigerant is extremely dangerous. Many special precautions must be taken when it is present. It can freeze whatever it contacts (including your eyes), it is heavier than air and can suffocate you, and it produces a poisonous gas when it comes in contact with an open flame.
The above information is directly from the Auto Insight program, which you can buy online from AutoEducation.com.
Common Problems:

From time to time the A/C system needs to be recharged to bring it back up to maximum efficiency. Sometimes a leak may cause loss of refrigerant and will need to be fixed before refilling. It's difficult to tell if a leak is present without specific test equipment so let it up to a professional.
Corrosion will cause the heater core (secondary radiator) to leak. This will manifest itself by leaving steam into the passenger compartment and fogging your windows. You will know there is a leak by the sweet smell coming from your vents. Unfortunately changing the heater core is usually not the easier job in the world, as engineers tend to squeeze them into some pretty tight spaces under the dash.
We get heat from the heater core, sort of a secondary radiator, which is part of the car's cooling system. We get air conditioning from the car's elaborate air conditioning system.
Despite its relatively small size, the cooling system has to deal with an enormous amount of heat to protect the engine from friction and the heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to the useful purpose of keeping us warm.
Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), the outside air entering your car. It also has the task of keeping the air at the temperature you select. These are all big jobs. How do our cars keep our "riding environment" the way we like it?
Most people think the air conditioning system's job is to add "cold" air to the interior of the car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of the air conditioning system is really to remove the heat that makes us uncomfortable, and returns the air to the car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air).
A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, the way we call copy machines "Xerox" machines). The compressor moves the Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to the evaporator. The evaporator is right in front of a fan that pulls the hot, humid air out of the car's interior. The refrigerant makes the hot air's moisture condense into drops of water, removing the heat from the air. Once the water is removed, the "cool" air is sent back into the car's interior. Aaaaaah! Much better. Newer cars have R-134 as the refrigerant, but work in the same way as R-12.
Sometimes we worry when we catch our car making a water puddle on the ground, but are relieved to discover that it's only water dripping from the air conditioning system's condenser (no color, no smell, and it dries!).
Note: Refrigerant is extremely dangerous. Many special precautions must be taken when it is present. It can freeze whatever it contacts (including your eyes), it is heavier than air and can suffocate you, and it produces a poisonous gas when it comes in contact with an open flame.
The above information is directly from the Auto Insight program, which you can buy online from AutoEducation.com.
Common Problems:

From time to time the A/C system needs to be recharged to bring it back up to maximum efficiency. Sometimes a leak may cause loss of refrigerant and will need to be fixed before refilling. It's difficult to tell if a leak is present without specific test equipment so let it up to a professional.
Corrosion will cause the heater core (secondary radiator) to leak. This will manifest itself by leaving steam into the passenger compartment and fogging your windows. You will know there is a leak by the sweet smell coming from your vents. Unfortunately changing the heater core is usually not the easier job in the world, as engineers tend to squeeze them into some pretty tight spaces under the dash.
Kevin Schappell maintains http://www.carbuyersclub.com where he gives advice on buying, selling, insurance, and financing. A mechanical engineer and car guy, Kevin has decided to spend his online time helping others learn about automobiles. To learn more about how your car works, Kevin has createdhttp://www.mycarwizard.com

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