How often Do HVAC Air Filters Need to Be Changed

Your HVAC system's air filter is much more important than you might think. Unfortunately, it is also something that most people don't pay much attention to. The primary purpose of the air filter is to trap dust and other airborne particles from getting inside the system and damaging your HVAC equipment. The filter also helps to improve air quality by preventing pollen, mold spores, dust mites, pet dander and other common indoor allergens and pollutants from circulating throughout the building whenever the heat or AC is running. Neglecting to replace your air filter regularly can lead to a whole host of issues including insufficient heating and cooling, increased energy costs and greater wear and tear on your HVAC equipment.

Replace your Air Filter

The general rule of thumb is that you should replace your air filter at least once every one to three months. Every two to three months is generally sufficient when you're not using your heating or air conditioning very often. However, during the middle of summer or winter when your system is running constantly every day, you may want to replace the air filter every few weeks. 

You can also choose to purchase washable filters instead of having to buy replacement filters every few months. However, you will still have to make sure that you fully wash, clean and dry the filter as often as you would replace a standard filter. Washable filters are more expensive up front, but they are generally a slightly cheaper option in the long run. That being said, most people opt for replacement filters due to the convenience.

When you replace your air filter, it is important that you choose the right filter for your system and that you put the filter in the right way. The filter will have an arrow that shows which direction it goes, and this arrow should always point toward the furnace or air handler. This is because air will flow from the ducts, through the filter and then into the furnace or air handler. The filter only works in one direction, which means it won't do its job if you put it in the wrong way.

How to choose the Right Air Filter

Most air filters are rated using the MERV (minimum efficiency reporting value) scale, which measures how effective it is at filtering out airborne particles of varying sizes. For residential heating and cooling systems, you are always best to go with a filter somewhere between MERV 5 and MERV 12. Anything below MERV 5 will generally not be efficient enough to prevent damage to your HVAC components, which is why these lowest-rated filters are typically only recommended for use in window or portable air conditioners.

Using a filter that is too efficient can also cause numerous issues for your heating and cooling systems. The reason is that the more efficient the filter is, the more it restricts the air flowing through the system. If the filter is too efficient, your system will struggle to draw enough air through the filter. This will basically have the same effect as not changing your filter as there will be no way for the system to properly circulate air throughout the building. 

Most residential HVAC systems are powerful enough to handle up to a MERV 12 filter, but this isn't always the case with smaller systems. Anything above MERV 12 will usually be far too restrictive, which is why these higher-rated filters are generally only used in larger, more powerful commercial and industrial HVAC systems. 

Deciding exactly what level of filtration your home needs usually comes down to what your specific priorities are in terms of cost and air quality. The more efficient the filter is, the more it will cost. This means that if your primary concern is protecting your HVAC system from damage, you are generally best to choose something between a MERV 5 to MERV 8 filter as these will be quite a bit cheaper.  

On the other hand, if you're concerned about the air quality inside your home, you may want to upgrade to something between MERV 10 and MERV 12. A MERV 5 filter will generally only be effective at trapping larger airborne particles like dust, whereas the higher-rated filters can also trap pollen, pet dander, mold spores and even smaller particles like exhaust and chemical fumes. This makes the higher-rated filters the best option if anyone in your home suffers from severe allergies or has any respiratory or breathing issues like asthma or COPD. 

If you're still confused about which air filter is best for your home, the experts at Wingate Heating, Cooling & Plumbing are happy to answer any questions you might have. We can also inspect your system to make sure it is powerful enough to handle a higher-rated filter. Our technicians work on all types of heating and cooling systems, and we can handle all of your HVAC installation, maintenance and repair needs, as well as your home's plumbing system. We have been serving customers throughout the Cincinnati area for more than 50 years, and we have what it takes to keep all of your home's most important systems working as they should. Give us a call today to schedule a service appointment or if you have any questions.