Help...blower fan is running but no cold air...


Old 04-22-08, 11:33 AM
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Help...blower fan is running but no cold air...

My AC is not blowing much air when is it running(for the lower unit). I had a technician came out a couple of days ago and he charged my system, added 2 lbs of freon to the lower unit and 1lb for the top unit. He also installed a couple of the "current reducer" (not sure what it is called) to help reduce the initial current draw when the conpressor kicks on. Now my AC is still not blowing cold air. I woke up in the middle of the night and the fan sounds like it is running, but no air is moving thought the air returning unit or out of the vents. Could my coils be dirty? I had the blower motor ohmed out and it was ok? Also replaced the capacitor to the blower motor. Thanks.
Old 04-22-08, 05:47 PM
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Ain't much you can do...other than call someone else with good credentials. In other words, someone knowledgeable.

Did the tech that added the refrigerant to your units FIRST checked temperatures and pressures to see if the extra amount of refrigerant was really needed?

Adding refrigerant to a system that does not need it will unnecessarily increase its operating pressures, which in turn will increase the temperature of the air in your house (the air literally becomes less cold). So, as wacky as it may sound, too much refrigerant will give you LESS rather than MORE cooling.

The "current reducers" you talk about are likely "hard start kits". Is a combination of potential relay and starting capacitor. It helps old compressors get started.
Old 04-23-08, 07:00 AM
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Air Flow problems

Pflor is pretty well on. There are any number of issues you could have but here are a few in a nutshell.

ASSUMING (heh) that you have the 'right' ammount of refrigerant in the system and the airflow is reduced from what it is normally then that means you have an air-flow problem.

This could be because you haven't changed the filters in 6 months (oops!) and the flow is down drastically, possibly enough to cause the evaporator coil to freeze up.

OR the evaporator coil could be dirty enough that your airflow is really low, possibly enough to cause the evaporator coil to freeze up.

OR if both the evap and filters are clean and he put in some refrigerant and it was cooling at the time when he left the leak could have blown out bigger and your low on freon again and the coil temp is dropping too fast and freezing up.

OR one of the first two was the case with or without really needing freon, he put freon in with the coil still fully/partially frozen and didn't really solve the problem. Can't charge a system when the coil is frozen and have any clue as to wether it is really charged enough!

There are a few things you could check yourself before calling someone out. The filters are the obvious first choice. Being able to see the side of the coil that is coming from the air filter and seeing how dirty it is/or isn't is harder or sometimes not doable by the homeowner easily.

Either call the guy back out and have him/her address these issues (and possibly look for the leak if it is really low again already) or get someone else.

Old 04-23-08, 08:49 AM
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When you run fan only, do you still have no air flow? Did you check the squirrel cage blades, make sure they aren't plugged with debris. Plugged cage blades is the same as having an airplane prop with no pitch, it can't "grab" any air.

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