• Seth Newsome

How Often Should I Change My Air Filter?

One of the most frequently asked questions we get at Stephenville Heat and Air is, "How often should I change my filter?" Usually, we get this question after one of those simple service calls where all we do is replace a dirty filter. The problem for homeowners is that for us to change a filter, they have to pay for a service call which means that's one expensive filter.


To avoid that pricey trip, you should change your filter frequently and often especially during the summer months. Today, we'll explore how often you should change your filter, what type of filters to use, and why it even matters.


How Often Should You Change Your Air Filter?


The meat and potatoes behind today's post is pretty straight forward. To make a long story short, you should change your filter when you can visibly see an accumulation of dirt, dust, or debris. For almost all homes this amounts to every 30 days or once per month. The problem most homeowners run into is really one of poor information and an abundance of trust in filter manufacturers.


Most filters you purchase at the grocery store or hardware store will be "90-day filters" which simply isn't true and will cause a lot of problems. You really trust your most expensive appliance and indoor comfort to changing a filter 4 times per year? I think not.

It's good practice to change your filter every 30 days regardless of what the packaging on your filter says.

With that said, it's good practice to change your filter every 30 days regardless of what the packaging on your filter says. And be wary of crafty marketers trying to sell you a "90-day" filter for two or three times the price of their "30-day" filter. In the end, you probably won't notice much of a difference between the two.


What Type of Filter Should I Use?


This is probably the most important question you could ask when it comes to your indoor air quality. Filters effectively come in two "throwaway" styles: pleated and non-pleated. The material my vary from manufacturer to manufacturer but typically pleated filters are made of some sort of cotton or polyester fabric broken (into pleats) across the surface of the filter. Non-pleated filters are almost exclusively made of fiberglass. They're flat and practically see through in most cases.


Filters can also come in more high-end options such as high efficiency particulate arrestance (HEPA) and reusable or washable air filters. HEPA filters, generally, are used in applications where getting allergens as well as potential pathogens and germs out of the air is of utmost concern such as hospital and clinic settings. Reusable and washable filters are great if you want to save a few bucks but can tend to clog over time and will need to be replaced at some point anyway.


Finally, consider the MERV rating of a filter. MERV basically measures a filter's effectiveness at removing airborne particles and is given a number value. The higher the number, the greater the filter's ability to remove particles. Most filter's MERV rating will be printed on the filter itself or on the filter's packaging.


So what type of filter should you use?


For most applications, we recommend using a pleated filter with a medium MERV rating--an 8 MERV pleated filter is standard from most suppliers. Higher MERV filters may work just fine for your system, but I've seen an instance where the MERV rating was actually too high for a particular system therefore blocking airflow and causing some serious problems. All in all, an 8 MERV pleated filter changed every 30 days will do you and your HVAC system just fine in most cases.


Why Do I Need to Change My Filter Anyway?


This is a good question which isn't often asked. Most homeowners think that their filter is there strictly for their in-home air quality (which is true), but the primary reason we have filters at all is to prevent dust, dirt, pet hair and dander, and everything else in our homes from causing problems with our HVAC system.


Airborne debris can cause some major issues such as dirty evaporator coils, poor airflow resulting in problems with both your heater and air conditioner, reduced efficiency, and outright failure of components. A lack of airflow from either the filter or evaporator coil causes your furnace, heat pump, or air conditioner to work overtime to compensate and can cause problems such as tripping refrigerant limits (high or low), freezing your evaporator coil, or worse.

A lack of airflow from either the filter or evaporator coil causes your furnace, heat pump, or air conditioner to work overtime to compensate and can cause problems such as tripping refrigerant limits (high or low), freezing your evaporator coil, or worse.

All of that to say, for the paltry price of a quality air filter, you can save yourself and your HVAC system some serious trouble down the line. Changing your filter is part of regular, healthy maintenance of your system and will greatly improve your indoor air quality.


Get the Premier Indoor Air Quality Experts


Improving your indoor air quality and in-home comfort is our top priority. From making sure that your home is correctly balanced and comfortable to saving you money on your heating and cooling bills, Stephenville Heat and Air is here to help. Our knowledgeable installers and technicians will help you find the right solution for your family or business needs.


Looking for a quote? Just need service or an opinion? Give us a call at 254-965-4644 to speak to a qualified technician or installer from Stephenville's premier air conditioning company.