This is a question is touched upon in the FAQ section of the website “Why is my air conditioner blowing hot air”, but I’ve decided to take a question a week, and expand on it, give you more information.  The answer I gave in the FAQ is that it could be a number of things.  I’ll give you the answers from my perspective.  The good news is—it’s blowing, the bad news is, it’s not cold air coming out of the vents.  This would work better with a flow chart but that’s not possible so let’s proceed.  One of the questions I will ask if you call is:  Have you ever had refrigerant added to this system?  If the answer is yes then I would ask you how long ago.  Last year, you say.  “I have to add it every year”, is another familiar response.  YOU HAVE A LEAK.  Your air conditioning system is comparable to the human body.  The refrigerant is like the blood in your body.  You don’t add blood once a year unless you are bleeding.  Same thing with your A/C unit.  You don’t need refrigerant every year unless you are leaking. 

I’ve heard it all, starting with, “The last company came out and fixed my leak and charged me so-and-so dollars, but now it’s not cooling again.  I tried to call them but they’re out of business.”  ac and heating classesYep, sounds about right.  ac unit sounds like running waterIt’s very rare that a freon leak can be FIXED.  heat pump window unit reviewMore times than not, the leak is in an area that can’t be repaired and the leaking piece of equipment must be replaced.  Another one I get is, “the last company put some stuff in my system to stop the leak, kinda like the stuff they add to leaking radiators.”  If someone tells you this, RUN!  Don’t let an A/C technician add anything to your system except refrigerant. 

It doesn’t work and it can cause more severe damage to your system.  It can cause early failure of your compressor.  Acme has been around for almost 30 years.  We fix things and fix them right, the first time.  Our customer reviews will verify that.  Our customers depend on us to give them honest advice and make the repair they know is necessary. Sometimes leaks start out small and refrigerant is only needed every couple of years.  Just keep in mind, adding refrigerant to any leaking system is throwing money away.  Some people think it’s okay to let them run low on refrigerant and just add when it gets really hot outside and the A/C system can’t keep up.  Just know that the cool refrigerant coming back to the compressor from the evaporator coil is what cools the compressor.  If the air conditioning system is running low on refrigerant then the compressor is not getting the same amount of cooling refrigerant and this will cause the compressor to run hot, which in turn can cause compressor failure. 

It’s a domino effect, as with most problems in the air conditioning system.  A small problem dominos into a big one if not immediately addressed.  When you know your system is not cooling, immediately TURN IT OFF.  I’ve been to so many houses where the customer knows the air conditioning unit is not cooling and leaves it running, I arrive, say the condenser fan motor is out, and the unit is just running and running.  Keep in mind, the compressor and the condenser fan motor don’t talk, the compressor doesn’t know the condenser fan motor is not running, it only knows that it’s getting hotter and hotter by the second until finally, an internal switch notices this and shuts the compressor off.  But not before it got really hot.  Then the compressor is off long enough to cool and guess what, it comes back on, runs until it gets hot, shuts off, cools, comes on, gets hot….you see my point.  It’s hard on a compressor to do this.  The same thing can happen when a compressor runs low on refrigerant…gets hot, shuts off, cools off, starts back up.  

The best thing is to have your system serviced each Spring before the really hot weather hits and make sure your system is running properly and full of refrigerant.  If you know you’ve got a leak, stop throwing money away and have the leak located, repaired or replaced. What is the best way to locate the leak?  We use a “sniffer” type refrigerant locater.  Some companies use dye that is added to your system and then use a UV light.  As I stated earlier in this post, adding anything to your system other than the refrigerant is tricky and we just won’t do it.  Also, you can use soap bubbles to suspicious joints and try and find leaks that way.  It’s just the choice of the contractor, what they feel is the best way to locate the leak.  The most common place we find refrigerant leaks are in the evaporator coil.  One of the problems with evaporator coils is that they condensate.  As they condensate year after year, they will start to rust, as they rust, the rust will flake off causing pinhole refrigerant leaks, and lots of them. 

Another problem with evaporator coils is the coil itself.  Like a radiator on a car, the coil has many pipes in a continuous pattern, back and forth.  On each end of the back-and-forth pattern is a U-bend.  Each u-bend represents a weld.  The cheaper/lower quality of the coil, the cheaper the metal and workmanship in this coil and the quicker the coil will develop leaks within it. Since low refrigerant levels are so common and a problem at probably 90% of the air conditioning service calls in Plano, Tx or Allen, Tx that we address, or any of the cities we cover, I thought I’d give more information this Friday morning about refrigerant leaks and the problems we encounter.    Why is the air conditioner blowing cold air, but the room is not cooling down? According to HowStuffWorks, there are several reasons why an air conditioner blows cold air but does not cool a room. Cleaning part of the unit is sometimes necessary to address the problem. It is possible that a part is malfunctioning or missing.

It is also possible that the unit is too small for the room, that the space lacks sufficient insulation or that the thermostat is set too high. What is a 10,000 BTU air conditioner? What is ductwork installation? HowStuffWorks recommends first checking that the temperature of the thermostat is set properly. Then check both the filter and the cooling coils for dirt if a unit is not providing sufficient cooling. A dirty air filter in the unit impedes air flow through the cooling coils and prevents the cool air from exchanging with the warmer air in the room. notes that portable air conditioners require a duct to expel hot air outside the cooled space. If this duct is leaky or missing, the unit blows both cool and hot air from the front of the unit instead of funneling the heat outside. With correct installation, these units help to cool a stubbornly hot room. According to the Department of Energy, ducts for a central HVAC system develop leaks. In a home where one room remains hot while the rest of the house is cooled, it is important to inspect ducts for leaks and make any necessary repairs.

It is also important to make sure that the air conditioner is rated high enough for the space that needs cooling. Both the size of a room and adverse conditions, such as heat from cooking appliances or insufficient insulation, affect how well a unit cools a room. How can a room air conditioner be repaired? To repair a room air conditioner, diagnose the problem and likely cause, whether it's not running or just not cooling. If the air conditioner is not runnin... To effectively cool a room, it is necessary to have an air conditioner with the correct capacity. To cool a 435-square-foot room, a 10,000-BTU air conditio... To determine the right size for a room air conditioner, homeowners need to calculate the square footage of the room and then use a cooling capacity chart, ... What are sources for parts to refurbish a Napoleon wood stove? What types of attic ventilation system are there? What are the specifications of Menards electric heaters? Can you fix heat pumps yourself?