Hail Damage on air conditioning units in the Phoenix area - What you need to know from thermal-medics.com

The residents of Phoenix felt nature's wrath on October 5th 2010.  Now, thunderstorms and small hail is not uncommon during our monsoon season, but this one was a whopper.  We had a very intense group of thunderstorm cells move through the valley and drop an incredible amount of large hail.  There is a  you tube video from a backyard during the storm.

Now how does this effect your A/C and why are we talking about it?  Take a look at some condenser coil fins after the storm:

another beauty:

This created a little 'boom' in the local economy.  For up to a year after the storm every man, woman and child was out roaming the streets offering to replace your A/C, roof, car windshield - anything that they could get a claim though the insurance.  Some serious crookery went on as high bids came in, adjusters were swamped and homeowners were stoked!!!

Now we are on the other side of this.  Many people had some damage but not enough to file a claim. Some didn't even know what happened to their unit and others had units installed but the hackery in some of the jobs left them with a new unit that never operated at full capacity.  Now we are past the one year point, most insurance companies will not let homeowners file a claim.

Lets talk about what happens when the condenser coil fins get bent like this.  The condenser (in A/C mode) whole purpose in life is to give up or reject the heat that the refrigerant picks up as it travels through the evaporator.  In other words the compressor squeezes the refrigerant, raising the temperature and pressure and as that hot gas is cooled in the condenser it........condenses into a liquid.  Now that hot liquid is free to travel back to the evaporator and pass through a metering device (TXV, capillary tube or fixed orifice) to expand cool and pick up that heat as the air in the living space is passed over it.  REMEMBER IN A/C AND REFRIGERATION ALL WE ARE DOING IS MOVING HEAT - NOT COOLING AIR - THAT IS THE RESULT OF REMOVING THE HEAT!!!!

This is why when you put your hand above the condenser fan,  the air is hotter than Hades.  It is pulling say 100 degree air from the outside across a 130 degree hot gas copper line and you now have 130 degree air blown up into the sky.  That 30 degree difference is the heat picked up by the refrigerant from the living space and a little from the heat of compression. We are moving the heat from the inside of your house to the outside air above your house!!

NOW, when you coil fins get all bent out of shape the airflow is restricted and A/C units hate restrictions to airflow.  The refrigerant cannot give up that heat as efficiently because the cooling area is reduced.  Now the temperatures and pressures will run hot, the evaporator is not getting to designed cooling temps and finally you are here wondering why your unit runs all day but never seems to cool to desired temps.

Condenser fins can be combed out to a certain degree.  This is a delicate process and must be done with a special tool.  It is effective unless the coils look like the pictures above then you just have to throw in the towel.  There are not replacement parts for horribly bent fins. 

If you have any questions on hail damage, air conditioning capacity, and the effect this all may have or have had on your unit call me or write in to http://www.thermal-medics.com/  If you suspect poor workmanship or have questions about an install do the same.  Send pictures, drawings... anything than can help.