4-Inch vs 1-Inch Furnace Filters The 4-inch thick air filter has a definite advantage over the 1” filter in terms of longevity, airflow and maximum filtering potential. Thus, if it fits your furnace, then a 4-inch air filter is better than a 1-inch air filter in regards to improving air quality.

Is a 4-inch furnace filter better than a 1 inch?

4-Inch vs 1-Inch Furnace Filters The 4-inch thick air filter has a definite advantage over the 1” filter in terms of longevity, airflow and maximum filtering potential. Thus, if it fits your furnace, then a 4-inch air filter is better than a 1-inch air filter in regards to improving air quality.

Is a thicker furnace filter better?

The Thicker, the Better Furnace filters can range anywhere from 1″to 5″ in thickness. In general, the thicker the furnace filter is the more efficiently your unit work and the longer it will last.

What is the difference between a 1 inch filter and a 4-inch filter?

Well, 4-inch filters have larger pleats. That means they have more surface area to catch particles, making them last 3–5 times longer than 1-inch filters. Most HVAC technicians recommend changing 1-inch air filters every 30 days, while 4-inch filters can be changed every 3–6 months.

Can I use a 1 inch filter instead of 4-inch?

Question: Can i use a 1 inch filter instead of 4 inches? Answer: If you are okay with more frequent replacement and little stress on the system, 1” filter can be budget-friendly alternative of 4” filters.

How long does a 4 inch filter last?

For 3- to 4-inch filters, replace them every 6 to 9 months. For 5- to 6-inch filters, replace them every 9 to 12 months.

Can I use 4 1 inch filters instead of a 4 inch filter?

While a 4-inch-thick filter is more efficient than a 1-inch filter, the right size depends on your furnace. If you measure the filter slot, and it’s large enough to accommodate the thicker filter, then you can use it. However, if the slot is less than 4 inches wide, you’re stuck with using that thickness.

How often should I change my 4 inch furnace filter?

A good rule of thumb is to change 1-2 inch filters every three months, 4 inch filters every six months and 5 inch filters every 12 months. Signs your air filter needs changed: The filter is visibly dirty.

Does furnace filter size matter?

Does Size Matter? You’ve guessed it! The answer is yes. It is essential to use the right size air filter for your HVAC unit to keep your system running smoothly and to reap all the benefits your air filter has to offer.

How tight should a furnace air filter fit?

How tight should a Furnace Filter fit? When you remove the existing filter, take note of the dimensions printed on its frame. Your new filter will need to match this size for the system to run efficiently. It should fit snugly but not so tight that you can’t easily slide the filter in and out.

Article first time published on

What happens if your furnace filter is too small?

If the filter is too small, it won’t cover the entire space and may allow dust and dirt to flow past. If you’re not sure what size filter you need, check the manufacturer’s specifications or ask your HVAC technician for help choosing the right product.

How many filters should a furnace have?

Most furnaces will have a V shape filter system; the system will take 2 filters. The filters go up into the plenum in a V shape. Make sure that when you re-install the top door, it goes over the furnace frame so it engages the safety switch. If not the furnace will not run.

Can I use a 2 inch filter instead of 1 inch?

As you can see the 2 inch filter will serve our needs MUCH better than the 1 inch filter. Even if the duct system is in good shape, using this filter will keep the system from struggling.

Is it OK to cut a furnace filter to fit?

Answering the Question: Is it okay to cut an air filter to fit? … Simply put, yes, you can cut an air filter if you know what you are doing, and if the filters you use will not become too weak from the cutting.

Why does my furnace filter get dirty so fast?

Leaky Duct Work According to ENERGY STAR, a typical house loses 20-30% of air through leaks in the duct work and poor duct connections. Leaving these untreated can not only kill your furnace filter quickly, but also result in higher energy bills.

Should furnace filter be changed summer?

The same HVAC system that moves air throughout your home during the winter, will be moving the air throughout your home in the summer. … Frequent filter changes will help to increase the lifespan of your entire HVAC system. So, yes, your furnace filter needs to be changed even in the summer.

Do bigger furnace filters last longer?

Home Size. Home size is an essential factor in determining the frequency of your filter changes. Large homes, for example, circulate larger amounts of air through the furnace or air conditioner. This means that the filter may get dirtier faster and require more frequent replacement.

What happens if you use the wrong size air filter?

When you use the wrong size air filter, or you install it incorrectly, the filter can’t effectively prevent dust from accumulating on the system’s motors and blowers. You’ll end up with a dirty furnace that can’t properly perform, and all of that debris could end up harming the system’s internal components.

What size filter does my furnace need?

Furnace filters are sized by width, length and thickness. The size on the filter is usually expressed in inches (example: 16″x20″x1″). A filter that is the wrong size will typically not fit, or may not stay in place, once installed. The owner’s manual for your furnace should tell you what size you need.

What MERV rating do I need?

We do recommend that everyone uses filters that have at least an 8 MERV rating. These filters will remove the majority of pollutants from your indoor air. If you have serious medical conditions making it difficult to breathe, you might want to get a filter with MERV 9-12 rating.

Do I need both a furnace filter and a return air grill filter?

While many people refer to air conditioning and furnace filters as if they’re different, this is not the case. Your furnace and your air conditioning system use the exact same filter, so there’s no need to worry about purchasing separate filters for each piece of equipment.

What happens if you don't change your furnace filter?

Without a new air filter, the furnace will overheat every time it starts up again. This is referred to as short cycling. Dirty furnace filters cause your furnace to work harder than it should due to a decrease in airflow. The harder your furnace works, the quicker its parts will wear out and need repairs.

Do air filters have to be exact size?

Since air filters are most often sold by their nominal dimensions, it is crucial to learn how to properly measure your air filter. When making your purchase, you should order your filter by its nominal size, rather than its actual size.

What size air filter do I need without a filter?

1. Step 1 – Measuring Length and Width (L x W). (If your filter is not a square, the smallest measurement goes first).
2. Step 2 – Measure the thickness (Depth) of your filter from front to back.
3. Step 3 – Put Your measurements together (L x W x D).

How do I know if my furnace filter is dirty?

1. Filter is a different color. …
2. Energy bills are higher than usual. …
3. Low air flow. …
4. Rise in physical issues. …
5. Headaches. …
6. Allergies. …
7. Carbon monoxide poisoning. …
8. Forces HVAC systems to work harder.

Why do I have two air returns?

Having two air return vents allows you to seasonally control which air is returning to the HVAC system. … The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.

Do I need filters in my return vents?

Your AC system should have a proper fitting filter on the return side. By placing a good fitting, high quality filter on the return vent, you will remove particles from the air before they can enter the AC system. A good filter will keep your air handling unit, coils, and ducts clean.

Is it OK to double up furnace filters?

Bottom Line: Putting two air filters on a central air system will only have the net effect of producing a higher utility bill and reducing the lifespan of your central air unit. In short, the use of two air filters is just a BAD idea!

What are standard air filter sizes?

10X2014 X 2020X2012X1214X2424 X 2412X2014X2520X2412X2414X3020X2512X3015X2020X30