How Do You Decide Between HEPA and MERV Filters for Your AC Unit?

Do Not Display

When you’re thinking about HVAC air filtration, there are basically two main options: HEPA and MERV filters. These terms differ in both filtration media and efficiency rating. During an average day, the entire air volume inside your home circulates through the system filter many times. The type and quality of your system's air filter directly affects the health and comfort of your indoor environment. It also impacts system energy efficiency as well as monthly operating costs.

Here are some facts about HEPA and MERV filters to help you make an informed decision about which is most suitable for your home.

HEPA

Short for High Efficiency Particulate Air, HEPA filtration removes more than 99.97% of airborne dust, pollen, mold spores, bacteria, smoke, and other particulates. However, the drawback of HEPA filtration is airflow restriction. In a typical residential HVAC system, installing the thick HEPA filter in the standard duct-filter mount will reduce system airflow excessively. However, two HEPA alternatives are available for consideration:

• Alteration of the home’s return ductwork to include a duct-bypass loop that diverts only a portion of airflow through the HEPA filter at any given time.

• For limited spaces such as single rooms, stand-alone HEPA filtration units incorporating powered fans are widely available.

MERV

HEPA and MERV filters do differ, and MERV filters are the most common type for residential HVAC use. Filtration is rated according to the MERV (Minimum Efficiency Reporting Value) numeral—a number between 1 and 20. Here are some facts about MERV filters to help you make an informed choice.

• MERV ratings below 5 are usually inexpensive fiberglass filters that trap only the largest visible particles of dust. They are not ideal to support optimum indoor air quality.

• Filters with MERV ratings of at least 8 provide the best balance between cost, filtration efficiency, and airflow. These are typically pleated cotton or polyester filters which provide increasing efficiency up to MERV 13.

• Filters rated MERV 14 and above may not be appropriate for standard residential use due to excessive airflow restriction.

For more information about the pros and cons of HEPA and MERV filters, talk to the professionals at Air Assurance.

What’s the Difference Between Air Filtration and Air Cleaning?

The winter is generally too cold to open the windows and fill the house with fresh air. The air inside your home will recirculate through the HVAC system and eventually the indoor air quality will suffer. In order to handle this problem, consider the different benefits air filtration and air cleaning can provide for your home.

Air Filtration

When the house is sealed, the air repeatedly circulates through the HVAC system. Every time that it is heated, a small deposit of dirt is left on the furnace, which can cause the furnace to run less efficiently or become damaged. The holes in standard filters are spacious enough to permit air to flow easily but small enough to catch most particles of dirt.

If allergies are a serious concern, a standard filter don’t help to clean allergens from the air. High-rated MERV filters have tiny holes to trap allergens but the improved air filtration comes with a high price. The increased workload for the furnace will cause a steep increase to your heat bill.

Air Cleaning

Air cleaners can keep your furnace clean without increasing your heating bill. They also remove up to 99 percent of the dust, mold spores, pollen, dander and other particles that make your family sick.

Which One is Right?

If the furnace is your main concern, an air filtration system will take care of it nicely. On the other hand, if you have family with asthma or allergies, a high-rated MERV filter or an air cleaning system would probably be a better choice for you.

Air Assurance has had the honor of serving customers in Broken Arrow, Oklahoma for over a decade. If you have any concerns about your indoor air quality, call us today!

Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). Credit/Copyright Attribution: “phloxii/Shutterstock”

Bewildered About What Type of Furnace Filter to Choose? This Guide Can Help

Buying the right furnace filter can make a big difference. With all of the choices out there, it can be hard to make a proper decision. However when you take into account all of the factors that are important to you in regards to your family’s health, indoor air quality and cost, the choice becomes much easier.First you must consider the efficiency of your filter by looking at its minimum efficiency reporting value, or MERV rating. The MERV ranges from 1-20, with 1 being the cheapest and least restrictive to airflow and 20 being the most efficient, collecting 99.9 percent of all airborne particles.A low-MERV filter provides just enough protection to keep larger particles out of the furnace. These are cheaper to use but do little to improve air as they are solely to keep your HVAC unit dust free. A cost-effective MERV 4 filter allows for decent airflow and catches most large particles like dust and lint and are good if you’re not overly concerned with air quality.These filters may be fine if you don’t have allergies; however, if you are sensitive to airborne allergens, you may want to consider installing an electrostatic furnace filter with a MERV rating between 8-10 that will catch pollen, spores and dander. If someone in your family has low immunity, consider a high efficiency, pleated synthetic cotton filter with a MERV of 14 or higher. These can be removed and cleaned, catch bacteria, most smoke and can last up to six years, if properly maintained.  While they do cost more, they will save you money in health care costs.Whichever you do choose, remember that filers with higher MERV ratings require more attention and regular cleaning or replacement. While higher quality filters remove more particles, they also put more strain on your unit due to reduced airflow so it is advisable to contact a qualified HVAC technician before making a change.For more information on furnace filters and HVAC needs, contact Air Assurance, servicing the Tulsa Metropolitan region since 1985.Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems).

Credit/Copyright Attribution: “Jezper/Shutterstock”

Finding The MERV Filter That's Right For Your Family's Health And Your Furnace Efficiency

Finding a MERV filter that works for your family, and helps your furnace to function efficiently, is actually a rather simple process. All you need to know is how MERV, minimum efficiency reporting value, works, and which MERV filter will work with your system.A MERV rating, developed by the American Society of Heating, Refrigeration & Air-Conditioning Engineers (ASHRAE), is designed to show how well a filter traps particles, and the size of particle it can trap. Higher-rated MERV filters will trap smaller particles. Low-efficiency filters Rated MERV 1-4, these filters offer the most basic level of protection for your furnace and your home’s air. They aren’t able to trap smaller particles very well, but do a decent job of capturing larger particles. If you’ve never evaluated your furnace filter before, it’s likely that its MERV rating is within this range. Mid-efficiency filters These filters, rated MERV 5-13, generally have an expanded surface, either through a pleated design or some other technology that increases the filter space, so they can trap more particles. The density of the filter’s surface is also critical to efficiency, and mid-range filters have denser fibers. Overall, these filters are the best choice for residential use because they allow enough air to flow through the filter, while balancing the capacity to trap particles of both small and large sizes. High-efficiency filters -- including HEPA It's possible to purchase a higher-efficiency filter, rated MERV 14-16, or a High Efficiency Particulate Air (HEPA) filter, rated MERV 17-20; however, both types of filters greatly restrict airflow and are not recommended for use with residential systems. For the ultimate in indoor air quality, you can opt to purchase an air-cleaning device that can be used alongside your HVAC system, which will use a higher-efficiency filter without affecting airflow.If you suspect that your furnace’s MERV filter could use an upgrade, or for any other heating and cooling questions, contact Air Assurance Heating, Cooling & Air Quality today! We've been serving homeowners in the Greater Broken Arrow area for more than 30 years. Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).  Air Assurance services Tulsa, Broken Arrow and the surrounding areas. Visit our website and get started today!     Maintenance Checklist image via Shutterstock