Why Does My Air Conditioner Smell?

An air conditioner is a system or a machine that treats air in a defined, usually enclosed area via a refrigeration cycle in which warm air is removed and replaced with cooler and more humid air.In construction, a complete system of heating ventilation and air conditioning is referred to as HVAC. Whether in homes, offices or vehicles, its purpose is to provide comfort by altering the properties of air, usually by cooling the air inside.

Air Conditioners; A Brief Introduction

In 1842, Philippines physician Dr. John Gorrie used compressor technology to create ice which he used to cool air for his patients. He hoped eventually to use his ice making machine to regulate the temperature of buildings and even considered cooling entire cities with a system of centralized air condition units.

Air conditioning engineers broadly divide air conditioning applications into comfort and process. Comfort applications seek to provide an indoor environment that remain relatively constant in a range preferred by humans despite changes in the weather conditions or in internal heat loads.

Process applications aim to provide a suitable environment for an industrial or a commercial process, regardless of internal heat loads or external weather conditions. Although often in the same comfort range, it is the requirements of the process that determine conditions, not human preference. These include; hospital operating rooms, aircraft conditioning, facilities for laboratory animals, data processing centres, nuclear facilities, etc.

In the refrigeration cycle, a pump transfers heat from a lower temperature source into a higher temperature heat sink. Heat will naturally flow in the opposite direction. This is the most common type of air conditioning.

Since evaporation occurs when heat is absorbed, and condensation occurs when heat is released, air conditioners are designed to use a compressor to cause two compartments, and actively pump a coolant around an enclosed system. The cooling liquid is pumped into the cooled compartment. Low pressure then causes the refrigerant to evaporate taking the heat with it.

In the other compartment, the refrigerant vapour is compressed and forced through another heat exchange coil, condensed into a liquid which then rejects the heat previously absorbed from the cooled space.

On health implications

Air conditioning has as much influence on human health as any generic heating system. Poorly maintained air-conditioning systems, especially large centralized ones, can occasionally promote the growth and spread of microorganisms such as legionella pneumophila, the infectious agent responsible for legionnaire disease.

One of the most important decisions to be made regarding a new home is the type of heating and cooling systems to install and the selection of the heating and cooling contractor since the operating efficiency of a system depends on proper installation as much as it depends on the performance of the equipment itself.

Poorly designed and poorly installed HVAC systems can have negative effects on the personal comfort by degrading the quality of air in a home and creating unhealthy conditions that may threaten the health of the homeowners.

Besides having properly installed a good air conditioning system, regular maintenance for the system is advised, in order for it to function effectively and efficiently throughout its years of service.

Smell Bad

The most important maintenance task is to routinely replace or clean its filters. Clogged, dirty filters block normal airflow and reduce a system’s efficiency significantly. With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil’s heat-absorbing capacity. Moreover replacing a dirty clogged filter with a clean one can lower your air conditioner’s energy consumption by 5 percent to 15 percent.

The air conditioner’s evaporator coil and condenser coil also collect dirt over time. This dirt reduces airflow and insulates the coil, reducing its ability to absorb heat. To avoid this, check your evaporator yearly and clean it as necessary.

The aluminium fins on evaporator and condenser coils are easily bent and can block airflow though the coil. “Fin combs” are tools that can comb these fins back into place and are available at air conditioners wholesalers’ shops.

• Occasionally pass a stiff wire through the unit’s drain channels to prevent clogging, as clogged drain channels prevent a unit from reducing humidity and the resulting excess moisture may discolour walls or carpet.
• Inspect the seal between the air conditioner and the window frame to endure it makes contact with the unit’s seal (moisture can damage the seal, allowing cool air to escape from your house)
• During winter, cover your room air conditioner or remove and store it
• Hire a professional service technician to find and fix problems with your air conditioning system once in a while.

If the mould is inside the duct work, it could be caused by; leaks in the air ducts, high indoor humidity levels or mould growth spreading from another source. By visually inspecting the ducts you can be sure whether there is mould growing. Call for professional assistance after troubleshooting the problem.

A rotten egg smell usually means there is a pest problem or a dead animal in your air conditioning system. In this case, the smell will be stronger when you get closer to the vents or you will find pest droppings inside the ducts. You will need to have a pest control professional locate and remove the animal.

Just like any other appliance in your home, the window air conditioner needs tender care and hence it is advisable to give it a thorough cleaning at least once a year.

Conclusion

Different air conditioner smells mean different things. A musty or ‘dirty sock’ smell is usually caused by growth of mould, mildew and bacterial on areas with lingering moisture. This is because besides cooling the air in your house, the air conditioner also removes excess moisture and if it’s not drained away properly, bacteria will build up inside the system. As warm air passes over those cold coils, condensation occurs. And if there’s any dirt or dust present, it provides grounds for mildew, mould and other bacteria.

I hope you have enjoyed reading this article as much as I did writing it. Feel free to share your comments, thoughts and suggestions in the comments section provided.