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Dodge Caravan
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Air Pollution

Why does the air conditioning unit in the house freeze when you change the filter?


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2006-09-13 18:57:01
2006-09-13 18:57:01

Short answer: Your system is low on refrigerant. Long answer: The only things that will cause an evaporator coil to freeze are; 1. It has a low coolant charge. 2. It has restricted air-flow. The low coolant charge causes dramatic coolant temperature changes when going through the evap. coil resulting in a colder than normal coil. The restricted airflow causes less heat transfer to the coil resulting in colder than normal coil. The coil of an HVAC unit running in AC mode should be @ or about 40 degrees... if you slow down the air crossing the coil, the "radiator" doesn't pick up as much heat as it needs to stay at that temperature, and begins to freeze the humidity that usually drains out of the housing through that PVC fitting you see comming out of it. Have an HVAC company come out and check the AC system, but be ready for some bad news... If you are noticing the system freezing up, chances are you have a refrigerant leak. (This is very bad, in that the system is a "Sealed system" nothing in, nothing out) That being the case, you will need to have it changed... the fast fix is a "re-charge". But it's just a band-aid on cancer... it will mask the symptoms, but won't fix anything. sorry. email me directly with further questions. Jack at discovertexasproperties dot com (just replace the "at" with @ and the "dot" with . )

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I know that if you don't change the filter for 6 months then you will be paying a lot of money to cool or heat your home. If the air flow is restricted then there is less air coming into the house or room and that makes the conditioner work longer and harder to attempt to get the temperature where it is set at.

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If they become clogged, your house can be filled with pollens and other pollutants but more importantly, it can task your air conditioning system and cause a possible shut down.

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No. They can't get through the enclosed system and inside the house there is a filter. When a filter is changed all that is seen is dust.

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The word filter explains it all, alike your house AC filter that you change so often to ensure you stay cool, I recommend that you change your gas filter twice a year.

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A filter with high resistance to air flow, as in high efficency types, may cause the coil to freeze. This is dependant on the system air flow. A more restrictive filter will reduce the airflow and MAY cause the airflow to be insufficent and cause the coil to freeze. Note: coil freeze ups will cause compressor damage. An expensive repair. A knowlegeable service technician can check your system air flow and determin if a high efficency type will be an issue or not.


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