I get a lot of questions about car air conditioning systems not blowing cold enough. Especially during hot humid summer days. Most people would like to see frigid cold air blasting from their small dash vents instantly upon request. Now that this page is getting some heavy traffic I am adding some additional information and a new “Simple Fixes” video at the bottom along with some related tools and equipment for people who want to take it to the next level. So lets get that cold air back. Remember when your car has been baking in the sun heat is stored up in large quantities and must be removed before it starts to feel cool inside. But what if the air does not seem to get cold after 5 minutes? There are many factors involved that affect the actual output temperature at the dash AC vents. To follow will be a few examples of common problems that I find when inspecting a car air conditioning system that is not performing as well as it should be. Without a doubt the most common problem that I find is an incorrect Freon charge.

The amount of Freon in the system is extremely critical. The manufacturer installs the exact amount that is required for the system to perform at its peak. This exact charge is so critical it is documented in the vehicle’s engine compartment down to the ounce. A few ounces short of a full charge can result in inadequate cooling under high heat loads due to lack of reserve refrigerant. A telltale sign of this condition would be for a compressor clutch to cycle on and off faster than usual. The rapid clicking sound generated from this condition can usually be heard from inside the vehicle. Sometimes when people try to recharge their system on their own they will actually overcharge the system which can cause poor cooling performance just as much as low Freon levels. In extreme examples an overcharge of refrigerant can even cause AC compressor damage and noisy operation. Not as common as the Freon issue mentioned above but one that is common in my area at this time of the year is a radiator or a condenser that has been considerably clogged with bugs, dust and dirt, or road debris and trash.

When this junk starts to reduce the airflow that passes through the radiator and then through the condenser it can cause higher than normal high-pressure readings. This in turn can knock several degrees off of the output temperature in the cabin. This is the kind of problem that slowly gets worse over time. It is very rare that people will take the time to check or clean the radiator and condenser. The fleet company I work for has made this operation part of the scheduled service operations. second floor air conditioning unitsWe have a pressure washer and we physically clean the radiator and condenser fins every 20,000 miles.air handling unit problems Although there are lots of other problems that can cause poor cooling the two mentioned above are ones that I find often. hvac unit not heating

If you think your car air conditioning is not blowing cold enough the first step is to check the output temperature at the center duct with a thermometer. Make sure the recirculation or max air mode is selected and the blower is on low speed. 40 – 50 degrees is perfect. On hot humid days in south Florida 55 degrees is welcomed. Step 2 is to have a professional connect a manifold gauge set and get high and low side pressure readings. With these readings a logical path of diagnosis can get your AC blowing cold as it should be. Read more on this subject if you plan on finding a mechanic to recharge the car air-conditioning. I put together a repair modules section on my you fix cars website that talks about the theory and operation of car air conditioning. Understanding how the system works is very helpful for problem solving. You can also head back to this blog’s main page and get some more automotive repair information. In this next video Pat Goss talks about things you can check at home before seeking service.

This is good stuff and worth the 4 minutes. Note at the end Pat recommends professional service for charging AC systems. This might be a bit over cautious but he is right that it can be dangerous for inexperienced do it yourselfer’s. Mr Goss is for sure right that putting too much freon in the system can destroy the compressor. It’s possible to do thousands of dollars in damage by doing it wrong! If you decide to go for it Read the instructions carefully.Air Conditioner or Heat Pump Diagnosis: This article is the start of our series on how to diagnose an air conditioner or heat pump that is not cooling: this article explains how to diagnose and correct air conditioning problems like lost or reduced air conditioner cooling capacity, reduced or no cool air flow, reduced or no actual lowering of the air temperaturer, or an air conditioner that won't start. First try our air conditioner checklist just below - try these steps before calling your HVAC service company. If not enough cool air is provided by your air conditioner, or if the air temperature is not cool enough, or if you just can't get your A/C unit running, this article helps diagnose and correct the problem with step by step things to check and links to more detailed explanation when you need it.

If you don't see information you want, ask us for it using the comments box on this page. If your air conditioner or heat pump is a split system or mini split system design (using a wall-mounted cooling or heating unit) our troubleshooting diagnostics are at SPLIT SYSTEM AIR CONDITIONERS & HEAT PUMPS. Is there no cool air at all coming out of the supply registers? Or is there air blowing out of the supply registers but it's not cool enough? Here we explain how to diagnose loss of air conditioning cool air flow or cool air temperature. Before ordering an expensive air conditioner service call to restore lost cooling capacity, here are a few simple stepsSome of these can be done by any homeowner, others may require a bit more expertise. Below we provide first a very basic Air Conditioning or Heat Pump Diagnostic Checklist, followed by more detailed descriptions of common problem cooling system topics. Following the checklist we provide more detailed descriptions, photos, and links to in-depth air conditioning inspection, diagnosis, and repair or improvement advice.

Where to start: check that the air conditioning equipment is turned on, the thermostat is calling for cooling, and that the blower unit or air handler is actually blowing air through the ductwork. Details of how to proceed in figuring out what's wrong with your air conditioner begin just below. If the air conditioning system is still not working, or if the A/C system is running but cool air is not coming out of the supply registers you probably need to call a service technician, but below are some things to check further yourself. The basic air conditioning diagnostic checks just below are followed by more detailed investigation of why the air conditioner is not working. But unless you already have a good idea of what's not working, start with these five steps. If the air conditioning system is still not working, or if the A/C system is running but cool air is not coming out of the supply registers you probably need to call a service technician, but here are some things to check further yourself.

Just after these checks we discuss what to do if the air conditioner is running but air flow is too weak (A/C Flow Too Weak) or too warm. Is the outdoor compressor-fan unit (COMPRESSOR & CONDENSING COIL) running? If not, be sure that the outdoor compressor/condenser unit service switch and the air conditioner indoor power switch, fuse, or circuit breaker are all in the "on" position. Check the outside compressor condensing coil for damage or blockage. A blocked condensing coil can cause the compressor to overheat, stop running, or become noisy and work poorly. If you cannot find your air conditioner controls and switches see A/C - HEAT PUMP CONTROLS & SWITCHES - list of controls and switches found on air conditioners and heat pumps Condensing unit fan diagnostics: at FAN, COMPRESSOR / CONDENSER UNIT we explain the diagnosis of problems with the compressor/condenser fan and fan motor. Also see ELECTRIC MOTOR DIAGNOSTIC GUIDE. At BURNED-OUT COMPRESSOR we explain that if the condensing unit fan is not working the compressor itself may shut down or even be ruined by overpressure or over temperature.

Also see NOISES, COMPRESSOR CONDENSER where some noise problems are traced to the cooling fan . Is the indoor blower unit running? If not be sure that the electrical power switch at your furnace or air conditioner air-handler is in the "on" position. Typically the air handler or blower unit is indoors inside the basement, crawl area, or attic. Sometimes there is more than one switch, such as one right at the unit and another at the entry to the room where the equipment is located, or even upstairs on a higher floor if your air handler is in a basement or crawl space. Make sure that the blower compartment cover or door is properly closed or an interlock switch may be keeping the system "off". Also remember to check for a dirty, blocked COOLING COIL or EVAPORATOR COIL. A coil blocked by ice or dirt will not produce cool air. A/C Cooling Coil Icing. If your air conditioning equipment is running but little or no cool air is coming out of the supply registers, check that your air filter(s) have not become blocked with dirt and debris.

Usually the air filter is right at the air handler or blower unit, or your air filter may be installed behind a grille covering a central warm-air return that sends air back to the air handler. See A/C Filter Problems for details In ceilings, walls, or floors, where cool air is supposed to be delivered to various rooms in the building, be sure that the register is in the "open" position (you will be able to see through it into the ductwork) and be sure you haven't blocked the supply registers with a carpet or furniture. Look for a duct damper or register that has been closed; look for a flex-duct section that has become disconnected, bent, or crimped or squashed. Remember that a duct may have become disconnected in an attic or crawl space. Look for an air filter that has come loose and blown into the ductwork, clogging it. At left you can see a ceiling air supply register that has leak stains around its opening - further investigation for a condensate leak or roof leak is needed.