UncategorizedApril 20, 2023by Alex

An unpleasant smell from the air conditioner in the apartment

The main purpose of the air conditioner is to create a favorable climate in the house for all family members. Ideally, this is fresh air, the optimal level of temperature and humidity. The support of such indicators falls directly on the split system.


This technique is simple and unpretentious in care, but even it has failures. The result is an unpleasant smell from the air conditioner, which quickly spreads throughout the apartment. The article describes why this happens and what are the ways out of the situation.


Reasons for the smell from the air conditioner


Most often, the problem occurs after a long period of downtime of the equipment, for example, in the summer, if the device was not turned on all winter. At the very first start, the smell of sewage or dampness appears. No matter what aroma fills the room, there are only three reasons for this.


Development of bacteria


Since the temperature inside and outside the equipment is different, condensation forms on its walls during the operation of the air conditioner. By the time of drainage through the drainage pipes, these water droplets are saturated with household odors and microbes.


When the air conditioner is constantly on, the condensate quickly leaves, not having time to release unpleasant aromas into the room. Otherwise, if the equipment “stands idle” for a long time, favorable conditions for the reproduction of bacteria and mold appear inside the unit. It is they who give that characteristic smell of mushroom dampness when turned on.


Absence of a siphon


Some negligent installers (and owners too) install air conditioners with condensate draining outside. As a result, water simply drips on the heads of passers-by or accumulates in a puddle near the wall of the house. It is not good and wrong to do so.


If you follow the installation instructions, then during installation, the drainage pipes are connected to the sewage system of the house, and a siphon is used to eliminate unpleasant odors. So, if you ignore the need for this very siphon, then all the “evil” from the sewer pipes will smell in the apartment.


Even if the siphon is installed, but the equipment is not used for a long time, the condensate will evaporate, and sewage odors will freely pass through the empty siphon.




Recirculation is one of the functions of the air conditioner. Its essence is that in order to save electricity, the device re-passes the air in the room through itself. “Fresh jets” from the street do not mix into these flows. What is the result? The equipment absorbs all surrounding smells:


– tobacco smoke and perfume aroma;

– plastic, synthetics;

– smells of food, animals, wet shoes, etc.


This mixture of odors accumulates inside the equipment, conditions, and returns. It is easy to imagine what a mind-blowing aroma will be at the exit.


How to deal with it: 3 ways to eliminate odors


It is easy to remove the smell from the air conditioner at home. For this, you can call specialists or, at your own peril and risk, do all the work yourself. The choice of cleaning method depends on the causes of the smell.


A small life hack: cleaning the room and cleaning the air conditioner filters will help to minimize the possibility of unpleasant odors. Equipment should be washed at least 1-2 times a month.


Treatment of the air conditioner with antibacterial agents


The air contains a large number of microorganisms, fungi, dust mites, and other harmful elements that negatively affect the human body. Most air conditioners can not only freshen the air but also make it cleaner, thereby improving the microclimate of the room. The equipment absorbs all the “ugliness” and over time it will need cleaning itself.


Even with regular cleaning, it will not be possible to remove all harmful organisms. You can fight them effectively only by using disinfection. For this, it is necessary to select powerful substances specially developed for wall air conditioners.


Disinfection will be relevant if:


– an unpleasant smell appeared;

– clear signs of mold are visible on the surface or inside the case;

– there is slime in the tray with condensate or in the drainage system.


In addition, disinfection is carried out every time the split system is switched from cooling to heating.


Installation of antibacterial filters


All split systems are equipped with odor-absorbing filters from the factory. But those who wish can equip their equipment with additional filters.


Independent drying of humidity with an air conditioner


The method is suitable for those split systems that are equipped with a fan shutdown function. That is, as soon as the air conditioner stops working, ventilation stops with it. The vaporizer automatically dries from drops of moisture and does not collect unpleasant odors.


Has the air conditioner started to smell unpleasant? No problem. After reading this article, you can easily get rid of any odors. And if you regularly take care of the equipment, wash, and clean your split system, then no extraneous odors will appear at all. The air conditioner will only perform its direct function – to create freshness and a comfortable temperature in the room.


Don’t wait for your air conditioner to fail. If not repaired promptly, there is a very high likelihood that a lengthy comprehensive repair will be required. Even a few days without air conditioning in the summer heat in San Diego County, California, will greatly discomfort the whole family. But by calling the handypersons at SDAC Heating & Air Conditioning, you can avoid this problem.


Contact us


(858) 788-1-777


[email protected]