by Ron Walker
A good thermometer is essential. You will use it every day. You must have one that can be clamped securely to the refrigeration piping. The first thing to use it for is checking the temperature of the air going into the indoor blower. Then check the air just inside the nearest supply air opening. The air coming out of the supply duct will be approximately 20°F. below the returning air to the equipment. If your cooling coil or filter or blower wheel are really dirty, then the difference in temperature will probably be higher. This means you may have good amount of cooling, but not enough air to get it from the cooling coil into the rooms. You may also be close to having icing of the cooling coil (evaporator) and the electric bill will be higher. Check these thing to make sure they are clean.
Read the section on filters if you have not done so, for this will be the cause of this dirty condition. If these things are dirty, they will have to be cleaned before you can do very many other things for the diagnosis of problems. If the evaporator coils are dirty, don't just brush them off and think you've gotten them clean. It's the stuff trapped inside the fins within the layers that will be a problem. You will have to have a service technician remove the coils, clean them and reinstall them for you. This is an expensive repair, but it will have to be done, and is well worth it to you in the long run. After cleaning, use the good filter, it should be changed often.
If you checked the temperature of the air into and out of the indoor unit and the differential is low, say 12°F versus the optimal 20, then you may have a cooling generation problem. The first thing to check now is the cleanliness of the outside units coils.
You won't be able, most likely, to tell if the coils of the condenser are dirty just by looking. You will have to use a hose and spray into the fins of the coil and watch the other side to see what comes out. You may very well see a bunch of stuff you didn't expect to see. If there is the slightest amount of clogging of the coil, then continue on to give it a really good bath. Chemical cleaners may be required.
You may have strong water pressure and you will have to avoid hitting the fins at an angle to prevent them from being damaged by the water. Spray vigorously, though, and give it a good cleaning. Don't just stand back and sprinkle it a bit and think it is clean--it won't be. Look over into the unit and watch the mud come out. Make sure the leaves inside the condenser haven't accumulated to the point of restricting the flow through the coils, too.
Turn it back on to check the temperatures again. Let it run for at least 10 minutes or more before you check these temperatures. If you got a lot of matter out of the coils, it will do wonders for the operation of the system. Recheck things now.
A good thermometer is essential. You will use it every day. You must have one that can be clamped securely to the refrigeration piping. The first thing to use it for is checking the temperature of the air going into the indoor blower. Then check the air just inside the nearest supply air opening. The air coming out of the supply duct will be approximately 20°F. below the returning air to the equipment. If your cooling coil or filter or blower wheel are really dirty, then the difference in temperature will probably be higher. This means you may have good amount of cooling, but not enough air to get it from the cooling coil into the rooms. You may also be close to having icing of the cooling coil (evaporator) and the electric bill will be higher. Check these thing to make sure they are clean.
Read the section on filters if you have not done so, for this will be the cause of this dirty condition. If these things are dirty, they will have to be cleaned before you can do very many other things for the diagnosis of problems. If the evaporator coils are dirty, don't just brush them off and think you've gotten them clean. It's the stuff trapped inside the fins within the layers that will be a problem. You will have to have a service technician remove the coils, clean them and reinstall them for you. This is an expensive repair, but it will have to be done, and is well worth it to you in the long run. After cleaning, use the good filter, it should be changed often.
If you checked the temperature of the air into and out of the indoor unit and the differential is low, say 12°F versus the optimal 20, then you may have a cooling generation problem. The first thing to check now is the cleanliness of the outside units coils.
You won't be able, most likely, to tell if the coils of the condenser are dirty just by looking. You will have to use a hose and spray into the fins of the coil and watch the other side to see what comes out. You may very well see a bunch of stuff you didn't expect to see. If there is the slightest amount of clogging of the coil, then continue on to give it a really good bath. Chemical cleaners may be required.
You may have strong water pressure and you will have to avoid hitting the fins at an angle to prevent them from being damaged by the water. Spray vigorously, though, and give it a good cleaning. Don't just stand back and sprinkle it a bit and think it is clean--it won't be. Look over into the unit and watch the mud come out. Make sure the leaves inside the condenser haven't accumulated to the point of restricting the flow through the coils, too.
Turn it back on to check the temperatures again. Let it run for at least 10 minutes or more before you check these temperatures. If you got a lot of matter out of the coils, it will do wonders for the operation of the system. Recheck things now.