The filter frames are made of beverage cardboard, which is designed to stay strong and withstand the rigors of everyday use. Recent advancements in air filters have enabled them to achieve high MERV ratings (11 to 1) with a low pressure drop. MERV stands for Minimum Efficiency Reporting Value and is used to measure how well a filter can remove particulates from the air. If you have pets, children, or allergy sufferers in your home or business, it is recommended to replace filters more often to maintain higher indoor air quality and reduce energy costs.
These filters are usually installed on wall-mounted ventilation grilles (most common in the south) or on the air controller (more common in the Mid-Atlantic and North Atlantic states, where the air conditioner is usually placed in the basement, near the boiler). If your air conditioning system uses a thicker filter (typically 4 to 5 inches and usually mounted on the air controller), it's likely designed specifically for medium-efficiency MERV filtration. A filter's Minimum Efficiency Value (MERV) rating indicates how efficiently it can remove contaminants from the air stream based on the size of the particles it can effectively capture. All of them (and Owen) told us that filters with a high MERV content can restrict air flow more than filters with a low MERV content, as measured by the decrease in atmospheric pressure generated by the filters when they are installed. However, these are rare circumstances, and whether or not to pay more for a better filter mainly depends on whether cleaner air is a priority for you or not.
Compared to the cheapest basic filters available, medium-efficiency MERV filters, such as the Nordic Pure MERV 12, can significantly reduce airborne dust, mold spores, pollen, and even smoke, and doing so can help alleviate respiratory conditions, according to an NIH review. Both are evidence that smoke-filled air is finding its way around the clogged filter instead of going through it, and that it's time to install a new one. In addition, an exhaustive, frequently cited independent test on the effects of MERV filters 8 to 13 on air flow and HVAC energy consumption (an indicator of how hard the equipment works) concluded that even “if steps are not taken to account for the greater pressure drop of filters with high MERV content, the air flow and energy penalties are not likely to be at least serious, not until the filter is full of dirt.”During a wildfire, you'll need to change filters more often than you would under normal air conditions, and there are some indicators that can help you know when it's time to replace one. If so, there are several examples of suitable filters that we recommend, such as the Nordic Pure MERV 12, a filter in perfect condition that we will look for first (because it usually costs less), as well as two other filters that also work well. In a conversation about the most common filter levels in retail, MERVs from 1 to 16, Owen said that this range “includes everything from filters that can catch a golf ball - I'm exaggerating a little - to filters that catch just about everything.”.
