Cleaning the Coils on Your HVAC System

If you are considering cleaning the coils on your HVAC system stop to consider your understanding of the heating and cooling system and how your skills as a handy man are. It will also depend upon what model you own.

Regarding the central air conditioning system the condenser coil is outside and generally easy to clean. The evaporator coil is inside and can be more complex.

You need to have a basic understanding of how the equipment works. First, the compressor creates pressure which compresses the refrigerant which has the properties to convert from a gas to a liquid. The pressure heats it up, while at a very high pressure the gas flows outdoors through the condenser coil where the majority of the heat is transferred to the outdoor air with the help of an array of aluminum fins. With the refrigerant cooled it condenses into a liquid at a capillary tube. Flowing back inside the now liquid refrigerant now expands, evaporating into a gas once more. The change from liquid to gas in the evaporator coil causes this coil to get very cold. Air blows over the coil by a fan and it is this cold air that exits your registers.

With a heat pump a reversing valve reverses the flow of the refrigerant sending the hot air to your vents rather than outside in the winter time.

The coils, whether inside or outside become dirty and it is this dirt that blankets them preventing the transfer of heat efficiently. In addition, a dirty evaporator coil can mildew sending contaminated air throughout the system and into your home.

The condenser coil being outside becomes dirty more often than the inside evaporator coil. This outside condenser coil needs to be kept clean from leaves, pine needles, grass clippings or any other debris. You should wipe or vacuum the housing clean. Use a paint brush to clean excess dirt off of the aluminum fins then rinse everything with a garden hose. The fins will bend easily so don’t use a pressure washer or hard tools to clean them. They can be straightened with a fin comb or you can ask your heating and cooling technician to straighten them for you.

The inside evaporator coil can be harder to do but doesn’t require cleaning as often. Generally, simply changing the filter every month will keep the evaporator coil fairly clean. Eventually it will need cleaning but that can take years before it is required. If it requires cleaning every two years or so then you should have your ducts and the evaporator coil housing checked. This may indicate they are not sealed.

Follow these instructions to clean the inside evaporator coil:

  • Turn off the power to the system in the main power supply.
  • Open the cover to the evaporator coil (usually next to the fan).
  • Cover the fan motor with plastic to keep water off of it.
  • If the coils and fins are easy to reach you can attempt to clean them. Again, try not to bend or mash the fins as this will reduce the units’ efficiency. Wipe clean using slightly soapy warm water with a soft cloth.
  • Don’t use any cleaner that contains ammonia or other chemicals that can damage the aluminum fins.

If this doesn’t clean the coils effectively you can repeat but your best bet will be to call in a licensed professional to do the job on extremely dirty coils. The professionals will use solvent-based cleaners or even stem cleaning. The coil may require removal to facilitate an effective clean outside for extremely corroded coils. Let the professional’s clean severely corroded coils, it isn’t a job for even the very handy homeowner.

Remember, clean coils save energy. Give us a call at Southern Home Service, our HVAC professionals will be happy to service your HVAC system. Call (205) 202-8797 today.

Choosing a Filter for Your HVAC System

Air Conditioning & Heating Filters

Changing the filter for your air conditioning and heating system, also called an HVAC system, is one of the most important things you can do to extend its service life. It helps to keep dust out of the system, thereby helping to maintain its peak performance and protect it from damaging dust. Your HVAC system is also an effective air cleaner depending upon your filter choice. Being at peak performance also saves you money on energy costs. Not all filters are created equally. Using a good filter can greatly extend the life of your system and reduce the number of repairs needed. Here we will compare the most common filters:

Basic cheap woven fiberglass filters screen out dirt and debris that can damage your blower motor. If you can remember to change them every month and air quality isn’t a concern these will suffice.

If you tend to forget to change your filter religiously and still want value buy a pleated filter which only requires changing every three months. They have smaller surface area and can capture smaller particles for a longer period of time without be detrimental to your systems airflow.

If you have pets, if anyone smokes or has asthma, allergies or other respiratory problems look to an electrostatic filter. They filter as well as magnetically attract particulates like dust and pollen. They can filter out smoke particles, bacteria, pet dander and odors. Some HEPA filters will destroy all bacteria by use of ultraviolet light technology. They are more expensive but some can last up to a year. Be aware though, they must be used in conjunction with a highly efficient vacuum cleaner for your home. Additionally, you must install an air purifier, keep your house clean, and wash or vacuum the filter every month. Otherwise, health experts warn the filters alone may be unable to handle the increased particulates.

Remember, filters must be cleaned winter and summer to prevent damage to your heating and air conditioning system and to prevent excessive energy usage.

Many filters carry a minimum efficiency reporting value (MERV rating), which gives an indication of their effectiveness. Generally, the higher the rating, the more effective they are. Fiberglass filters generally have a MERV rating of 4. Pleated filters generally have a MERV rating of 6. Electrostatic versions MERV rating starts at 8 with the top of the lines ones being 12.

It is easy to forget to change filters, and especially with the pleated filters that require changing on every 3 months. Unchanged they clog, causing overheating which shuts down the burner in a furnace. Eventually the limit switch fails and your furnace then fails to fire up at all. The service call and a new limit switch are going to cost you considerably more than a new filter would have. Mark the day to change it on your calendar.

You should also keep a check on your filter as dust conditions may vary affecting when it needs to be changed. If you prefer not to take chances there is an air filter gauge by General for about $16-20. It measures the airflow between the furnace and the filter through a small hose.

Some systems use washable and reusable filters. These also require regular cleaning to prevent breakdowns and increased energy usage.

Properly maintained your heating and air conditioning system should last you 10-11 years. It is an investment in your health and comfort. With regular filter changes and bi-annual maintenance from your heating and air conditioning technician you’ll get the most from your product for many years to come.

Air Conditioning Tips

Air Conditioning Tips: Getting The Most For Your Money

With energy costs higher than ever, keeping costs down is high on almost everyone’s list.  Investing in a new system is the best investment for your money overall as energy efficiency continues to improve. If your not quite ready to take the plunge on a new energy efficient system you can cut costs using the following tips to help keep those energy costs under control beginning with your air conditioning:

Have an air conditioning technician perform a yearly maintenance check to ensure your system is operating as it should. Any problems can then be addressed at that time. It is better to tackle problems before they become break downs. A good example is clearing a stopped up drain line on your air conditioning system. Left untouched it can overflow, rotting floors causing potential damage to other areas where the water flows.

Allow air to flow freely by keeping air returns and air registers clear of blockages such as furniture, drapes or rugs.

Have your air conditioning service company check your ducts for leakage and seal ducts that penetrate exterior walls .

Routinely change filters. Pick a day of the month such as the first and change your filter every month. Dirty filters cause your system to work harder and use more energy.

Switch to a digital thermostat. Depending upon the brand, a digital thermostat can give you greater flexibility in programming what temperature your home is and when. Digital can allow you the assurance that your system runs when it should, and not when it shouldn’t. For example, you can program it to run at an energy saving temperature in the day time and after you go to bed. Yet run at a more comfortable temperature when you and your family are up and about. No more getting up out of bed because you forget to adjust the temperature for sleep!

In addition, make certain your thermostat is located in the appropriate area. If it is located on a cold outside wall contact your air conditioning service company to have it relocated. If it is too close to a air register or in a drafty location its accuracy will be adversely affected.

Finally, if your ducts haven’t been cleaned in 10 years or more, or if you have noticed an increase in allergies, you may need to have your ducts cleaned. Depending upon how efficient your air filter is your ducts become dusty as dirt and lint particles move through them. You may also notice more dust than usual in your home, or a filter becoming more dirty than it used to.

Taking care of your system with regular maintenance insures your system lasts longer and performs at its best at all times.