If you set your filter up backwards, the normally collective end of the device will not face the air supply. In effect, your filter will help keep debris in the air. This results in a clogged filter and improperly cleaned air when it reaches your lungs.
What problems can a backward filter cause? The most common thing you will notice is the inefficiency of the filter. It will be harder for the air to flow, which would take a toll on your system. More strain means spiked utility bills.
Incorrect filter installation or installing the wrong filter can leave your engine open to dirt and debris. When the engine's air intake is not completely covered by a filtering element, extensive damage can occur.
If the filter is placed in the wrong direction, the finer pores on the other side of the filter will make it difficult for air to pass through the system. When that happens, there will also be a decrease in the cooling performance of the AC.
The blower fan in your HVAC system may not be able to handle anything stronger than MERV 12. A filter that blocks airflow will raise the air pressure in the HVAC ventilation system, which can damage ducts and even the AC and heater.
If the fuel filter was installed backwards, it can indeed cause problems. A backward fuel filter may restrict fuel flow to the engine, leading to increased wear on the fuel pump and potential pump failure. To resolve this, you'll need to remove and reinstall the fuel filter correctly.
If you install your filter in the wrong direction, air will have a hard time flowing through the filter's material and your air handler will have to work overtime to make up for the loss of airflow. This is not only a waste of energy, but it can also possibly damage your air conditioner or heating system.
After replacing the filter, you should wait at least 12 hours before running the system. If the AC is still not blowing cold air, it could signify that you have a refrigerant leak, a damaged condenser, or your entire mechanical system needs maintenance.
If you are looking at a furnace filter, find the arrow that indicates the proper airflow direction. That arrow must always face toward the furnace and away from the return duct that carries the air in need of heating or cooling.
If installed backwards, the filter drier will become useless. Take care not to overheat the newly installed filter drier when using a torch for brazing a sweat-type drier to the liquid line. The brazed connections must be thoroughly cleaned and fluxed when called for.
Beyond the cost of improper filtering, you will likely suffer from a decrease in indoor air quality. The filter is designed to remove a lot of unwanted debris, but only when installed in a certain direction. If you set your filter up backwards, the normally collective end of the device will not face the air supply.
Your furnace can, technically, run without a filter. However, we strongly recommend you don't run your furnace without a filter for any length of time. With air constantly moving through your furnace and your home, dust and debris can quickly build up, even in a matter of minutes.
Changing a furnace filter is simple. First, make sure your furnace is turned OFF so it doesn't blow air when you remove the filter. Next, locate the filter housing on your furnace. This is different for each model, but you can normally find it between the air intake and the furnace.
A backwards filter prevents air from flowing into the furnace, which prevents air from flowing out of the furnace. When this happens, your system will need to stay on for longer periods in order to reach the set temperature. The more that your system runs, the more stress your system will endure.
Consequences– If the technician makes the mistake of installing the drier in the wrong direction, the drier will not work and serve the purpose for which it has been designed. So, no filtration of contamination and no drying of moisture.
Reduced Efficiency of the System: An improperly sized air filter can create an imbalance in the airflow, which means the system may not operate at its designed efficiency. When the HVAC unit is forced to work harder, it consumes more energy, leading to increased utility bills.
If an air filter is installed in the wrong direction, air will have to pass through the filter via the less porous side. This will make it more difficult for your air handler to keep air flowing through the filter, which will force your furnace to work harder and consume more energy to make up for the loss of airflow.
The structure of an air filter is such that one side is typically more porous than the other. This difference is not just a manufacturing trick — it's a deliberate design to maximize the filter's efficiency. The more porous side is crafted to face the incoming air, allowing it to capture airborne particles effectively.