Your furnace system relies heavily on the efficiency and quality of the air filter you’re using. Choosing a suitable air filter is as important as the rest of your furnace parts.
Therefore, when choosing an air filter it’s important to consider some aspects. On top of these aspects is the MERV rating of the filter. In the article, we will dig deeper into what is MERV rating and what is the recommended MERV for furnace filters. We’ll also explain other crucial aspects regarding furnace air filters.
What Is MERV?
First of all, the term MERV stands for Minimum Efficiency Reporting Value. It’s a term created by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). It’s created to make a rating system that measures the size of the particles that filters are to capture.
The MERV measuring scale ranges from 1 to 20. The higher the number, the more the filtration and the smaller the particles captured by your filter. Yet, that doesn’t mean that you should get the highest number because it may overload your system.
MERV Rating System
The rating exists to help you realize the efficiency degree of each air filter and to match it with your needs. Filters with 1-4 MERV can remove particles like pollen, dust mites, spray paint, and carpet fibers. These filters are most suitable for residential AC units.
5-8 MERV Filters can capture smaller particles like cooking dust, mold spores, hair spray, and furniture polish. They’re also suitable for residential and industrial workplaces.
Filters with 9-12 MERV can capture lead dust, milled flour, auto and welding fumes, and pet dander. These filters are suitable for residential and industrial places and hospital labs.
MERV rating of 13-16 is found in high-quality filters as they can capture bacteria, smoke, and sneezes. However, these filters aren’t for furnace systems. They’re used for superior commercial applications like in hospitals and surgery rooms.
Recommended MERV For Your Furnace Filter
The most convenient MERV rate for houses and apartments’ furnace filters is 7-12. Although higher MERV can block more particles, it’ll also disturb the airflow in your furnace ducts. That’s because they tend to have small pores that force the system’s fan to work harder than it should to get the air through. Moreover, this can damage the whole furnace system and highly increase your electricity bill.
Filters with 7-12 MERV are the moderate options. Still, you need to check if your furnace system has a maximum MERV rating, so you don’t end up overloading your system.
The decision of which specific rating to choose primarily depends on many factors. Some of them are the size of your place, the number of people living there and if anyone has certain health issues. Also having pets and the air quality where you live affect your choice.
A 7-10 MERV is a basic filtration option. Yet, if you have a pet or live in a place with poor air quality, you’ll need a filter with at least 11 MERV. It’ll help capture pet dander as well as smoke and smog.
The same applies if there’s someone in your place with respiratory health problems like allergies or asthmas. In this case, it isn’t recommended to use filters with less than 11 MERV rating.
Bear in mind that the higher the rating, the more expensive the filter. That’s why choosing the most suitable option can save you money while still providing good filtration quality.
Other Aspects to Consider
While the MERV rating indicates the quality of your air filter, there are other aspects that you should put into consideration. Some of these aspects are the material of your air filter and the maintenance they need.
The material of an air filter is one of its crucial features as it affects the efficiency and the durability of the air filter. It also affects maintenance periods and procedures.
The electrostatic filters are reusable and washable, and also have disposable types. They work through making a static charge by the friction of the movement of the air resulting in particles clinging to the filter.
However, they don’t cause additional electricity usage. They’re corrosion-resistant and more expensive than some other types like fiberglass.
Pleated air filters are more efficient and long-lasting than fiberglass and synthetic filters. What gives them a high-efficiency level is their large surface area and small pores. These pores trap small particles including bacteria and viruses. Also, they don’t cause any disturbance to the furnace system airflow.
Those air filters are the cheapest in all types. They’re disposable and also allow maximum airflow. However, fiberglass filters capture large airborne particles more than small ones. This isn’t very suitable for someone with health issues or if you have a baby or a pet.
Polyester air filters are more expensive than fiberglass. Yet, they give more protection by trapping a huge volume of airborne particles. Moreover, they’re durable and of high strength.
High-Efficiency Particulate Air (HEPA) air filters are of the highest efficiency as they can trap most of the airborne particles. Although they give high-quality filtration, they cause problems to furnace systems airflow. The workload of HEPA filters may break down your system and also give you high electricity bills.
It’s important to check your filters regularly. Clogged filters decrease efficiency and cause health problems. Besides, not maintaining your air filters can overload your system and lead to a breakdown.
The number of occupants, pets, and the quality of the air can make you change your air filters frequently. The time between maintenance periods can be longer if there are fewer people and pets, and good air quality.
Fiberglass filters need to be replaced or washed thoroughly every month. Pleated ones are likely to be replaced every 1 to 3 months. Yet, electrostatic air filters must be removed and cleaned once a month.
Different types of filters come with guidelines on when and how to replace them. Following them shall make maintenance easier for you.
Choosing the right MERV rating isn’t a difficult process. All you need is to consider what each rate provides and the aspects related to your house and its occupants.
Filters with 7-10 MERV are middle-ground options when it comes to quality and cost. However, you’ll have to go for higher than 10 MERV if anyone in your place has a respiratory health problem.
Eventually, it’s essential to consider the air filter material and its maintenance-related details.