¿Cuál es el mejor filtro de aire para su hogar?

Para muchos propietarios, seleccionar e instalar un filtro de aire es un ejercicio de bricolaje. Creemos que está bien. Después de todo, cambiar el filtro de aire es algo bastante fácil de hacer.

Pero hoy en día hay mucha controversia sobre los filtros de aire, en parte porque hay muchas opciones de filtración. ¿Cuál es el mejor filtro de aire para ti? Todo depende de a quién le preguntes y cuáles son sus prioridades.

El mejor filtro de aire para tu hogar depende de...

Varias cosas, en realidad. Incluyen todo lo siguiente:

• Subjetividad: ¿Cuánta filtración le parece suficiente? Si siente que su aire está lo suficientemente limpio con un filtro simple y, en general, se siente cómodo en cuanto a la calidad del aire, es posible que no necesite nada pesado.
• Priorización: Tal vez quiera asegurarse de que está usando un filtro de aire de bajo consumo (más información en un segundo), o tal vez quiera asegurarse de que su sistema de filtración tenga en cuenta un componente en particular. COV, por ejemplo. Sus prioridades personales determinarán qué filtro seleccionar.
• Problemas de salud: ¿Tienes alergias? ¿Te molesta el moho durante los meses más cálidos? Luego, deberá usar un filtro que atrape las esporas de moho y el polen. Por otro lado, tal vez no seas tan sensible y no necesites esforzarte para filtrar esos contaminantes.
• Eficiencia energética: Los filtros de aire restrictivos pueden degradar la eficiencia de su sistema HVAC, por lo que es posible que deba encontrar un equilibrio entre la filtración efectiva y el funcionamiento eficiente de su equipo.
• Integridad operativa: En algunos casos, los filtros de aire restrictivos pueden sobrecargar su sistema HVAC y provocar una falla prematura del equipo.
• Simplicidad de mantenimiento: Si olvidó cambiar su filtro en el pasado, podría tener sentido usar filtros que solo requieran reemplazo o limpieza una o dos veces al año.

¿Confundido? ¡No temáis! Estamos a punto de sumergirnos en las opciones de filtración de aire, darle una idea de lo que hay y ayudarlo a tomar una decisión informada.

Sepa lo que está tratando de filtrar

Algunas personas son sensibles a los COV. A otros no les importa el olor de la caspa de los animales. El polen, el moho y el polvo agravan las alergias de algunas personas.

¿La línea de fondo? Hay muchas cosas que podrías estar tratando de filtrar, o no.

Antes de seleccionar un filtro de aire, es una buena idea determinar sus prioridades de filtración. El sistema más común para medir la capacidad de filtración de un filtro de aire se conoce como MERV, o valor de informe de eficiencia mínima. Los filtros de MERV bajo (piense en MERV 1-4) filtran relativamente pocas partículas en comparación con los filtros de MERV alto (piense en 11-16).

Según el tipo y la densidad del medio filtrante, diferentes filtros pueden reducir o eliminar:

• Polvo: Este es el contaminante más básico que los filtros de aire buscan eliminar. Incluso el filtro de aire menos potente evitará que una cantidad sustancial de polvo ingrese a su sistema HVAC y circule por toda su casa. (generalmente MERV 1-4).
• Polen, ácaros del polvo y moho: Las personas alérgicas deben buscar filtros que atrapen estos contaminantes (generalmente MERV 5-8).
• COV: Si es sensible a los olores fuertes de los productos de limpieza, artículos para el hogar o cualquier cosa que libere gases en su hogar, busque filtros que eliminen específicamente los olores y los COV. Many will include a carbon layer to capture the odors (usually MERV 8-16).
• Bacteria: Now we're getting into hospital-grade filtration. Some people need filters that can remove bacteria due to high sensitivity or because they have a chronic illness (usually MERV 13-17).
• Viruses: HEPA filters can usually remove viruses and other tiny particulates that slip by the media in other filters (usually MERV 15-20).

MERV values vary depending on the filter media type and size, and they're not uniform across all brands and filter applications. So one MERV 13 filter might filter bacteria while another doesn't. It all depends.

For perspective, most 1" filters that homeowners install themselves have MERV values between 6 and 12.

Choosing an air filter type

Here's where things get interesting! Now that you know what you're trying to filter and have a sense of what MERV range might get you there, it's time to consider air filter type.

1" pleated fiberglass filters

Everyone's familiar with these, and you've probably dealt with them in one form or another. MERV values usually range from 4 to 14, and the filter packaging tells you what sort of contaminants the filter is capable of capturing.

But here's the thing:We don't really like these filters. Especially not the high-MERV ones.

Why don't we like them? Because they restrict airflow to your HVAC system. Pleated, high-MERV filters definitely capture a lot of pollutants, but they also restrict the movement of air into your blower or furnace. As a result, the fan has to work harder to heat and cool your home, reducing efficiency. These filters can also cause liquid to flood back into the compressor, leading to premature equipment failure.

Basically, they increase static pressure within your HVAC system. That's not good.

So, what should you do if you have a return grille filter system or your ductwork can only accommodate a 1" filter at the plenum? We recommend avoiding the high-MERV 1" filters (above MERV 8 is pretty restrictive). The air filters we give our clients who have service agreements are actually 1", non-pleated filters made of polyester media. These cover all the air filtration basics - dust and pollen removal, for example - without restricting airflow.

When you need better filtration than what a 1" MERV 8 filter can provide, the best solution is to invest in…

Media filters

For many people, media filters are the best of both worlds:Serious filtration (MERV 11-16) without the airflow restrictions of 1" filters. Great stuff!

A media filter lives between your return plenum and your furnace, so your system might require some retrofitting if you're not already set up for one. They have more surface area than 1" filters, which is why they enable better airflow. And you only have to replace them once per year.

Most media filters are what we call "low pressure drop" filters, which means they have a minimal impact on your system's static pressure. This is a good thing. It's why media filters are such a great option for indoor air quality and overall HVAC efficiency!

Another thing that's great about media filters:coverage. Unlike most 1" filters, they're surrounded by a solid cabinet that prevents unwanted (and dirty!) air infiltration. A lot of 1" filters aren't effective because they allow air to go around the sides - so much for high MERV values, right?

HEPA filters

Usually packaged as a HEPA "system," these filters are the best of the best. VOCs, bacteria, viruses… HEPA filters capture nearly everything. Technically speaking, they trap particles as small as 0.3 microns in diameter, which is ridiculously small.

For perspective, a single hair from your head is about 45 microns wide.

Since HEPA filters contain incredibly dense filtration media, they usually require an additional fan to push air through the filter. Your blower or furnace fan won't be able move enough air through the filter unassisted, which is why HEPA filters are usually installed as part of a system with an included fan.

Air filters are great, but they can't fix everything.

We all need some level of air filtration. If nothing else, you want to filter out dust so that your indoor HVAC equipment doesn't get dirty.

But air filters can't cure every indoor air quality problem. For example, an air filter can't remove humidity from your home or prevent air infiltration from the outdoors. And if you're installing one inside a duct system that's already dirty, it's not going to clean the pollutants that have already collected there. You'll need to clean the ducts, too.

The same is true when it comes to energy efficiency. Upgrading to a media filter can reduce static pressure if you're changing from, say… a 1" pleated MERV 14 filter to a bona fide media filter. But your air filter won't solve the "big picture" static pressure issues like duct sizing, duct restrictions, equipment sizing, and register/grille selection.

Then there's this: If you're not changing your filter according to the manufacturer's instructions, you could be doing more harm than good. Dirty filters impose major restriction on airflow, further impeding efficiency and speeding along the decline of your HVAC system.

Most 1" filters are good for 90 days or so before you need to throw them away or wash them. Media filters typically require annual replacement, so there's less maintenance.

The first step toward better indoor air quality, but definitely not the last

Air filters are your first line of defense against contaminated indoor air. For some people, a simple filter is enough. Others need a more powerful filter. And many people require a solution beyond air filtration, like dehumidification, an ERV, or UV lights.

If we were in Arizona, humidity wouldn't be the source of so many air quality issues. This isn't Arizona, though. This is the hot, humid American South. A good filter is a good start. But in our climate zone, it's rarely the end of the journey.

Just remember that indoor air quality is all about priorities, sensitivities, and the unique requirements of your home. Start with the filter. If that's not sufficient, keep exploring.