Furnace Filters

Furnace Filters

How many times do you inspect your furnace? Chances are that you never think about it provided it’s functioning well in winter and summer. For your furnace to continue operating efficiently, you should either clean or change it regularly. 

How does a furnace operate?

A conventional forced-air furnace pulls in air through return ducts. The air is then taken through a heat exchanger for warming, after which a blower fan facilitates its movement across an array of ducts that extend into different rooms across your home. The furnace runs until temperatures in your home reach your thermostat setting. 

What’s the role of a furnace filter?

The main function of a furnace filter is to safeguard your blower fan from contaminants such as hair and dust which can penetrate through when the return duct draws in air. It also stops contaminants from being transmitted back into your surroundings. This helps improve the quality of air in your home. 

Rating of filters

Furnace filters are rated with MERV (minimum efficiency reporting value) and the ratings range between 1 and 16. Filters with a higher rating can eliminate a bigger percentage of particles. However, you need to know that a higher rated filter will let in minimal amount of air. 

As a result, the furnace ends up working harder and this can result in malfunction. A minimum rating efficiency value between 8 and 11 would be appropriate for many homes. Before purchasing a filter, you may want to consult your furnace manufacturer to establish the maximum MERV rating for the model of your furnace. 

Remember, some home development hubs have their own specialized rating system for their products which may slightly vary from the MERV scale. Establish what their rating translates to on the MERV scale before buying a filter. This way you can be sure that you’re using the ideal unit for your furnace. 

Types of Filters

There are various furnace filter types available today with the pleated disposable kind being most common. These are available in a vast range of sizes and standard ratings. Pleated filters are specially designed from polyester and paper and are ideal when it comes to filtering different household allergens and particles. Prices vary depending on the size, brand, and filter rating. You should inspect your pleated filters every month to rule out the chances of blockage. Replace or clean them after three months. 

Disposable fiberglass filters

These are the cheapest types of filters available today. They’re generally blue and look like a spider-web. These filters are available in numerous standard sizes but usually have lower ratings and are lighter than their pleated counterparts. As a result, you should examine and replace your disposable fiberglass filters more often than is the case with pleated filters.

 Washable filters

These are also known as permanent reusable filters. They’re designed with either a plastic or solid aluminum frame and are more adequate than their disposable counterparts. You can easily clean them with water or through vacuuming. They’re available in a range of ratings and sizes but are more costly. With proper maintenance, permanent filters can last up to 5 years. Be sure to clean your washable filters every three months. 

How often do you change your furnace filter?

As we’ve already seen above, you should replace or clean your furnace filter every three months. This way, you can be sure that both your furnace and the filter will continue functioning appropriately. Remember, while this filter is designed to trap airborne particles and dust as air penetrates through your furnace, a blockage in the furnace can inhibit airflow. This can eventually lead to malfunction of the furnace causing costly breakdowns. 

Inspect your filter every three months

Even though filter cleaning and replacement should be executed every 90 days, you should examine your filter monthly. This enables you to establish whether your filter is clogged and can continue operating well, or whether you need to clean or replace it to prevent malfunction. If your furnace filter is dusty, grey in color, and has an accumulation of debris, that’s a clear indication that it’s ready to be changed.

How do I find my furnace filter size?

Furnace filter sizes are determined by thickness, length, and width. The size of this filter is often conveyed in inches. If you purchase the wrong filter size, it’ll neither fit nor stay in place after installation. Find out your right filter size from your furnace manufacturer’s manual. Assuming you’ve lost your manual, all you need is to use your furnace model number and search for the filter size online. 

How do I know if my furnace filter is dirty?

Watch out for these signs. 

Rising energy bills

Have you noticed a questionable increase in your energy bills? If you have, chances are that your filter is either clogged or dirty and needs to be cleaned or replaced. Keeping a tab on your energy consumption can be an arduous task, more so with changing temperatures. Your bills, however, should alert you that something is amiss. Did you know that by changing your filter you can save up to 15% on your energy expenses?

You and your family members keep falling sick

Poor health can often be linked to dirty furnace filters. With fluctuating seasons come various health complications such as sinuses and allergies. However, if you get sick after switching on your furnace this can be an indication that the air in your surroundings is contaminated. Failure to clean or replace your filters can lead to severe health complications. 

If there’s a Burning Smell

A burning odor in your furnace could be as a result of overheating of the filters or blower motor. Your furnace requires the right amount of air flowing through to avert overheating. Dirty and clogged filters can restrict airflow in the furnace and if there’s a burning smell you should clean and replace them immediately.

A longer runtime with minimal heat

If your furnace takes longer than normal before heating your home, you need to inspect your filters. Chances are they’re dirty and need to be cleaned or replaced. 

Increased dust inside your home

If you notice increased dust in your home even after a thorough cleaning process, chances are that dust flows in your home via the filters. Remember, dust will linger because the root problem hasn’t been solved. This is where you should clean or replace your filters. 

What are the best furnace filters?

Numerous furnace filter options are available and choosing the right one for your furnace can be a difficult task. One thing you should keep in mind is that picking the wrong filter can do more harm to your furnace leading to major breakdowns. Here is a list of some of the best furnace filters to ease your search.

AIRx HEALTH 20x25x1 MERV 13 Pleated Air Filter

AIRx HEALTH 20x25x1 MERV 13 is one of the best furnace air filters available today. This unit is designed to transform your heating and air conditioning system into a house cleaner. As a result, it helps reduce bacteria, respiratory irritants, viruses, smog, and mold from your home. 

  • Micro-particle magnet

AIRx HEALTH filters play the role of a micro-particle magnet by trapping and confining ultra-small contaminants that can trigger health complications. With theses furnace filters, you can be guaranteed that your home will be healthier for you and your loved ones. These filters also come in handy to protect your home from debris, dust, and allergens. Further, they’re designed to prevent blockage in your heating and air conditioning system as a result of dust accumulation. 

These filters guarantee that your furnace operates at optimal efficiency, reduce energy and maintenance costs, and facilitates enhanced airflow. AiRx Health filters come with a high-efficiency filter media and more pleats for each square inch. The more the pleats, the better the air flow. What’s more, they promote enhanced particle holding ability. These filters can last up to 90 days in many homes. Replace the filters every two to three months depending on their state. 

Nordic Pure MERV 13 Pleated AC

Nordic Pure MERV 13 Pleated AC comes with a high MERV rating and is specially designed to help filter cigarette smoke, pollen, dust, pet dander, dust mite debris, smog, and mold spores. It’s also effective in eliminating fireplace smoke from the air. Apart from cleaning or replacing this unit every three months, you should examine it monthly to ensure it’s not clogged with debris. 

FilterBuy MERV 8 Pleated AC Furnace Air Filter

Maintaining cleanliness in your house especially when there are pets can be a difficult task. You can ease your struggles with the FilterBuy MERV 8 Pleated AC Furnace Air Filter, that’s designed to trap pet dander. This unit comes with a MERV rating of 8 making it effective when it comes to eliminating debris, dust, pollen, and lint from the air. It’s available in different sizes to fit a wide range of furnaces in the market. While it can function appropriately for three months, you may need to inspect it every month. 

Filtrete Micro Allergen Defense HVAC Air

Do you always sneeze and sniff in late winter or the onset of spring? Investing in one of the best furnace air filters can be what you need to eliminate allergens from your home and relieve the symptoms. Filtrete Micro Allergen Defense HVAC Air is specially designed to trap allergens from the air. This filter comes with a MERV rating of 11 and features an electrostatic charge which comes in handy to help with the particle capturing process. 

It’s effective when it comes to eliminating household dust, dust mite debris, lint, mold spores, pet dander, pollen, and smoke from the air. This filter can continue functioning well for three months but you should assess it from time to time. There are various sizes to choose from depending on your furnace. 

According to existing customer reviews, while this filter functions well, you may need to change it frequently, especially if you have multiple pets or your home is located in an overly dusty area. This will be necessary to avoid damaging your cooling and heating system which can be costly to repair.

Honeywell FC100A1037 Ultra Efficiency 4″ Furnace Filters

Honeywell FC100A1037 Ultra Efficiency 4″ Furnace Filters come with a MERV rating of 10. They’re available in different sizes to fit different types of furnace air cleaners. What’s more, you can buy it in different packs which contain between one to five units. This unit features deep filtration pleats and is more effective when it comes to eliminating contaminants from your surroundings than single-layer filters. This filter will continue functioning well for three months. However, people who keep lots of pets need to inspect and clean or change their filters frequently to avoid clogging. 

Honeywell Elite Allergen Pleated FPR 10

If you’re in search of one of the best furnace filters, you can’t go wrong with this Honeywell Elite Allergen Pleated FPR 10. It comes with a MERV rating of 13 and is available in different sizes, meaning you can use it in a vast range of furnaces. This filter is designed to eliminate particles from the air as small as 0.3 microns. 

It also comes with an electrostatic charge, enabling it to trap microscopic particles. This unit is specially designed to eliminate pollen, dust, lint, mold spores, pet dander, bacteria, and odor from the air. It can also be effective in eliminating smog particles and smoke. While you can expect the Honeywell Elite Allergen Pleated FPR 10 to continue functioning well for up to three months, you’ll need to examine it from time to time. 

Rheem Basic Household Pleated FPR 4 Air Filter

Sophisticated air filters can be costly and if you’re working on a budget, chances are that you won’t afford it. If you’re searching for a cost-friendly furnace filter, the Rheem Basic Household Pleated FPR 4 Air Filter should be your go-to gadget. It comes with a MERV rating of 8 making it effective in eliminating pet dander, pollen, dust mite debris, and dust from your surroundings. 

If you suffer from allergies, this unit will help relieve the symptoms. According to customer reviews, this filter is cheap albeit effective. If you live under circumstances that require you to change your filter frequently, the Rheem Basic Household Pleated FPR 4 Air Filter is what you need. 

Honeywell Superior Allergen Pleated FPR 9 Air Filter

Mold spores can pose a health risk to your family. When it comes to choosing an air filter, some homeowners opt for those that can trap these contaminants and eliminate them from the air. Are you in search of a good quality filter that can help you maintain a clean and safe home? 

If you’re, Honeywell Superior Allergen Pleated FPR 9 Air Filter is one of the best furnace filters available today. It comes with a MERV of 11 and is designed to remove contaminants as small as 1 micron from your surroundings. You can use this filter to eliminate other contaminants such as dust mite debris, lint, dust, pet dander, microscopic allergens, pollen, smoke, and bacteria. There are different sizes available and you can use it continuously for three months. Remember to examine it for clogging every month.


If you’re searching for the best furnace filter for your home, these reviews should help you pick one that best fits your needs. 

My name is Isabel and welcome to Blooming Air I created Blooming Air to be a place where homeowners can keep their homes healthy for them and their families with high-quality air units.