| As a home owner you should be aware of what is | | | | C. Tru-flow air meter. A measuring device installed in |
| involved in an air conditioning tuneup. If you read any | | | | the filter slot. Some techs believe its accuracy drops |
| home maintenance articles this spring, most will | | | | with poor duct design. |
| encourage an A/C tuneup; some will even claim 25% | | | | D. Temperature drop across the system is not an |
| savings. Predicting savings without knowing what | | | | accurate measurement of air flow, while temp drop is |
| type of tuneup received is a little silly. Encouraging a | | | | important in diagnosingit will not accurately determine |
| tune up without explaining the difference between an | | | | air flow |
| average tuneup and a high quality tuneup is a shame | | | | 2. Clean the condenser. The out door unit should be |
| and expensive. | | | | sprayed with a heavy foaming cleanser that soaks |
| Most tuneups claim to adjust, check, reset, or modify | | | | for ten to fifteen minutes before rinsing. |
| back to factory settings. What does that mean? It | | | | 3. Measure indoor and outdoor conditions. Indoor wet |
| implies that when the service tech is done your | | | | bulb, indoor dry bulb and out door dry bulb should all |
| system will be good as new. What it really means is | | | | be measured. A qualified tech will have the tools for |
| that the ad is not very specific; tough to figure if | | | | this. After all measurements are taken the tech |
| you got your moneys worth. | | | | should plot them on a sliding chart that will determine |
| First a little insight, the tuneup is the basic advertising | | | | required super heat. Super Heat is an HVAC |
| model for most HVAC companies. The idea being | | | | measurement that sets proper refrigerant charge. |
| they sell you a $59 tuneup hoping you're so | | | | 4. Adjust refrigerant charge, as important as airflow. |
| impressed with the work that it will lead to a new | | | | After airflow is set, the condenser is cleaned and |
| furnace install when the time comes. Any HVAC | | | | super heat is determined, the tech can hook up his |
| company will happily service a customer for years | | | | gauges and set the refrigerant charge. |
| just for a chance at landing the new equipment job. | | | | 5. Other useful measurements. |
| If that logic is stretched out the more tuneups the | | | | A. Temperature drop across coil should be 18-22 |
| more future jobs so why not drop the tuneup price? | | | | degrees, this is universal. |
| Just one problem as price drops, pressure to do | | | | B. Temperature drop across outdoor unit. The tech |
| more tuneups per tech increases and the quality of | | | | will know this depending on unit. |
| the tuneup suffers. | | | | C. Amp draw of compressor:b this will depend on size |
| What should a quality tuneup include? | | | | of unit. |
| 1. Measure airflow of system, absolutely critical for | | | | For any company to do this work correctly it will |
| capacity and efficiency. Most air conditioners require | | | | cost more than $59. Tell the dispatcher what work |
| 400 cfm of air to operate at capacity. There are | | | | you want done and understand that it will cost more. |
| three ways to measure airflow | | | | If it costs twice as much as a junk tuneup it's worth |
| A. Static pressure measurement. This is the most | | | | it for your comfort and wallet. Some companies will |
| accurate method providing the blower wheel is | | | | only pull and clean blower wheels on a Time and |
| cleaned. | | | | Materials basis and thats okay. Now you can talk to |
| B. A duct traverse. This involves drilling a series of | | | | your tech with out worrying about being bluffed into |
| holes in your return drop to measure air flow with a | | | | a bad job. |
| wand style meter. | | | | |