It will operate without one, but you'll risk potential damage to your system and to your health and the health of your family, and that's just not worth it. One of the primary functions of the air filter on your furnace is to keep dust and other airborne particles from collecting on your furnace's inner components.
Technically, you can temporarily run a furnace without a filter. However, it's important to emphasize the word “temporarily” here. Running a furnace without a filter overnight, for example, isn't likely to cause problems, but you should never allow this to turn into a long term solution.
If something happens and you have to pull your filter out for the day or even a day or two, it's probably not going to cause major problems right away. However, it's never a good idea to leave the filter out of your furnace for any longer than that.
A dirty filter in your furnace will generally lead to the following consequences: The furnace can overheat and turn off as a failsafe. Your home won't achieve the warmth or comfort you want. You can severely damage your furnace's internal components.
A clean furnace filter will prevent large-sized debris from entering your actual heating system. A filter will catch things like pet hair, lint, dirt, dander, and more. Without it, all of these particulates could find their way onto and even into your furnace's most sensitive interior components.
Dirty air filters are a frequent cause of furnace inefficiency. These filters trap dust, dirt, and debris, which can build up and restrict airflow. This blockage can cause the heat exchanger to overheat and the furnace to stop functioning properly.
Unkempt air filters may negatively affect indoor air quality by spreading pet dander, dust, and other allergens throughout your home. This may lead to irritated eyes, nose, and potentially breathing problems.
With a furnace blowing cold air, the first question you should ask is if the furnace has been turned ON. Two thermostat issues that could cause your furnace to blow cold air include (1) your thermostat is still set to COOL, not HEAT and (2) your thermostat fan is set to ON, not AUTO.
As a general rule, it is never a good idea to run your air conditioner or HVAC system without an air filter in place. Any amount of time spent doing so can lead to permanent damage and the possibility of needing expensive repairs.
You might wonder about the risks of running your AC without a filter, even temporarily. The simple answer is: not for long. Ideally, your AC should never operate without a filter for more than 6-8 hours. Going beyond this can negatively affect both your system's health and your home's air quality.
Without a filter, the furnace's inner components will develop dirt and grime buildup that will prevent them from working correctly. If you don't use an air filter, you will need a costly furnace replacement faster than you'd expect.
If you let it run very long without filtration, contaminants will build up. IAQ plummets when there is no filtration. Your family may experience health problems as contaminants and dust move through ductwork into the home. Mold spores could proliferate in the ducts, causing breathing issues.
If the filter is still in good condition, light should shine through. If the filter is dirty or clogged with debris, the light will be obstructed, indicating it's time for a replacement. The presence of visible mold is another one of the dirty HVAC filter symptoms that indicates it's time for a replacement.
The danger of not changing the air filter in the house for a long time is that it will eventually lead to furnace damage. This means that the entire system will get destroyed by the excess heat. Replacing the entire system can cost you enormous amounts of money, and it's almost the same as buying a new HVAC unit.
Clogged air filters can run havoc on your HVAC system. If you're still unsure what happens if you don't change your HVAC filter, it can be a health hazard. It can lead to system failure, and the components won't last long or consume more energy.
The standard recommendation is to change your furnace filter every 1-3 months, depending on the type of filter you have and the conditions within your home. For instance, if you have pets or if someone in your household has allergies, you may need to change the filter more frequently to ensure optimal air quality.
Cleaning an air filter only has two additional steps from replacing one. Again, the first step is to turn off the HVAC system. Find the service panel, open the furnace, and then locate your filter and remove it from the furnace. From here, you'll want to place it dirty side up and gently vacuum the large debris.
If you were to use your home furnace without an air filter, all that dust and debris could get stuck in your system and cause a rather large buildup. Over time, these buildups can clog and damage your system. To protect and extend the lifetime of your system, we recommend only running your furnace with an air filter.
If your filter becomes clogged, it can cause your furnace to shut off as a safety feature to prevent damage to the furnace. To fix this problem, simply replace your air filter on a regular basis. If you have pets, be sure to change your air filter more frequently.
This might seem like a small detail, but cutting an air filter down to a smaller size can sometimes damage the structural integrity of the filter. This is especially true for higher-end filters. The filter size should be listed in the instructional manual that came with your HVAC unit.
On the new filter, find the arrow indicating the proper airflow direction. The arrow must face toward the furnace and away from the return duct that pulls the air in need of heating or cooling.
Dirty Air Filters
So, the furnace is triggered to stop, then it cools down only to fire back up again. This short cycling continues to repeat until the furnace receives the airflow it needs. Dirty air filters are one of the most common reasons behind furnace short cycling.