Thursday, May 23, 2013

Air Conditioner - Regular Maintenance and Start-Up


There are several things that are good practice when it comes to ensuring that your central air conditioner will run at peak efficiency for many years. First and foremost, never operate your air conditioner when the outdoor air temperatures are below 18 degrees C (65 degrees F).

Regular maintenance of your condenser unit (outside unit) should include ensuring that your unit is clean and free of debris. Many times these units are beside trees or tucked behind flower beds and can easily get clogged with leaves, dirt and paper. The unit's efficiency is based on its ability to draw outside air in through the sides and condensing coils and expelling hot air out the top. Heat is transferred from hot to cold. In very simple terms, the condenser unit works by increasing the pressure and temperature of the freon above the outside temperature. This allows heat from the house which has been transfer to the freon by the evaporator unit (indoor) to be transferred to the out side air and expelled out the top. This transfer is dependent on the amount of air that can be drawn into the unit, so if the sides and coils are clogged with debris the unit's efficiency is significantly reduced.

Another factor to consider is the space around the unit. The outside unit should have a minimum of 18 inches around the unit on all sides to allow for proper airflow. Many of us like to conceal these units under trees, beside or even in flower beds. This is never a good thing if minimum clearances for airflow are not maintained. Again, the implications are reduced efficiency and added pressure on the compressor which can reduce the life expectancy of the unit.

One other very important factor to consider is start-up. Start-up of your air conditioner in the spring should be a planned event. Do not wait until the weather forecast predicts hot and humid weather. Many simply wait for that hot day, switch the thermostat over from heat to cool, set the temperature and think they are good to go. You may be doing more harm to your system than you know. The most important and expensive component of the entire system is the compressor motor. If you look in the top of your condenser unit you should see the compessor located under the fan and most times covered with a nylon weather boot. This is the heart of the system and one of the only mechanical components in the system.

In the condenser unit there is a heater coil that heats the oil which lubricates the compressor motor during operation. If you are like most people and you turn the main power off to the system in the fall by flipping the breaker at the main electrical panel or the disconnect fuse located beside your condenser, you have also turned off the power to the heater. It is very important to pre-heat the oil before the condenser unit starts operation in the spring. Powering the unit activates the heater coil inside your compressor. In turn, this heater warms up the liquid refrigerant that has combined with the compressor oil during the winter and turns this liquid back into a gas again. Starting the system when the oil is cold puts extra stress on the compressor motor and can seriously damage it. It is highly recommended that power to the condenser unit be turn on at least 24 hours before operating the air conditioning system in the spring.

Again, planning your start-up is a good thing and should start with cleaning the unit ensuring the coils are free of debris. Looking at the clearances around the unit and trimming any shrubs, trees or plants within 18 inches. Lastly, power the unit by turning the breaker back on and the disconnect fuse at least 24 hours before you plan on using the air conditioning system. Follow these steps and your system should run at peak efficiency for many years.

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