There's a lot of snake oil and questionable products lining the shelves of the average auto parts store. From octane booster to VTEC fluid (ha!), it's hard to separate the genuinely useful products from the chaff. So when A/C Pro sent me a few canisters of its do-it-yourself air conditioning recharge system, I was a bit skeptical. The idea is that most aging car air conditioning systems that don't blow as cold as they should suffer only from low levels of refrigerant. The way A/C Pro works is that you plug a can into your car's air conditioner and simply refill the system with R-134a refrigerant and the necessary lubricants to rejuvenate aging seals and moving parts. I've laid out detailed instructions for using the A/C Pro product in the gallery below. Check it out for photos and a full walkthrough. Putting it to the test With the car running and the air conditioning system powered on, I located the air conditioner's low side connection port. Air conditioning systems are essentially split into two parts, the low- and high-pressure sides, and the cooling happens as the refrigerant is compressed and passes from a state of high pressure to low pressure.

After locating the low-pressure connection point, I used the A/C Pro's gauge to measure the pressure of the system. (Be sure to keep your hands clear of moving parts; I got a nice friction burn on the back of my hand from a moving accessory belt.) If the pressure looks low, then it's time to refill and recharge the system using the A/C Pro product by pulling the trigger on the filler nozzle. The filler nozzle and pressure gauge combo gives feedback and control over the refilling and the user should take care not to overfill the system, which can adversely affect the system's ability to chill air. Our test car, a 1999 Toyota Corolla, was blowing 84-degrees-Fahrenheit air at the beginning of the test. I saw a 20-degree drop in vent air temperature to about 64 degrees. That's a big-enough jump to prove that the product does work -- at least as a short-term fix. Systems with moderate to large leaks could eventually depressurize again and may still need a mechanic's help. A/C Pro tells us that for the vast majority of systems, this simple recharge should be enough.

All in, prepping, measuring, and recharging the system took me about 30 minutes. However, the Corolla's pressure levels were exceptionally low and I took more time than I probably needed to measure air temperatures and take photos, so it's still a fairly quick fix. I should note that the Corolla was actually my second attempt to test the A/C Pro product. My first attempt was under the hood of a 1990s vintage Volkswagen Jetta. Unfortunately, this system had bigger problems than the A/C Pro product could fix. There's only so much that a simple refilling, recharging, and lubricating product can do. If there's physical damage (such as a seized compressor or a serious leak), you may need more help than A/C Pro can supply. Still, for only about $45 to $50 at your local auto parts retailer, A/C Pro isn't a bad DIY first step before calling in a professional (and potentially expensive) mechanic.< 1 2 34 > 2 posts, read 65,903 times 19,534 posts, read 39,623,807 times

Originally Posted by GAwareagles51 In the middle of record setting heat (if not otherwise) set your thermostat higher than 72ac unit jacks 17,825 posts, read 24,764,727 timesair handling units for clean rooms What does this sound like to you.how does air conditioner work pdf Sounds like you need to raise the thermostat a few degrees. 27,818 posts, read 27,120,608 times Could be a couple of different issues. It could be airflow has dropped from a clogged coil, bad fan motor, clogged fan blades or a combination of all three. It also could just be you're using the wrong filter. Are you using a pleated type "high efficiency" filter or one of those hog hair filters? You can try taking the filter out and see if that stops the freezing (make sure the coil is completely thawed though before you try this).

If that solves your problem then go buy some of the el cheapo air filters which aren't restrictive but do allow more debris to get by them. It also could be low on refrigerant. It could also be a combination of all of the above. Without more information, which you're most likely not going to have access to, we can't help you any more than that. you'll need to call a technician. Originally Posted by Pitt Chick Assuming this is a 10 SEER system or less the Approach for the evaporator coil should be 35� below indoor ambient. That means at 72�F the evaporator should be operating at around 37�F. The "approach method" is the expected difference in a properly operating HVAC system between condensing/evaporating saturation points and the indoor/outdoor ambient air temperature. Originally Posted by MrRational That should mean a higher heat load on the evaporator (unless there is an airflow problem) which wouldn't cause freezing issues. 1,940 posts, read 6,665,304 times

4,221 posts, read 7,025,500 times Originally Posted by southgeorgia For the record, the average residential system would hold less than four pounds, so that was pretty close to empty. 2,376 posts, read 4,177,108 times My first guess is a clogged air filter, this is the most common cause. If you compare a new air filter with old one, you'll notice that the new one is white and the used one is off white in color. This is when you should replace it. you should never allow it to get so clogged that it's any darker than off white in color. If your filter is OK, my next guess is the coil is clogged with dirt caused by not replacing the filter often enough. 43,216 posts, read 43,024,441 times If your filter and coil are not blocked then Your low on freon. Before you ask here is why. The pressure in the suction line is kept at a level that keeps the evaporator from freezing. If your low on freon the pressure drops in the line bringing the temperature below freezing causing it to ice from the evaporator right back to the compressor.