Any air filter rated higher than 13 can restrict airflow to the point of damaging your HVAC system, resulting in costly repairs. It's important to make sure that the rest of the system is configured to handle the increased restriction that filters create. In general, filters with higher MERV ratings capture higher percentages of particles, as well as smaller particles. MERV-13 is practically the ideal rating for home use.
It's worth noting that surgeries and HVAC systems don't use fiberglass filters. If your home's HVAC system is not capable of handling MERV 13, opt for a filter with the next highest possible rating. Technology for HVAC units has progressed since then and most modern units in recent years should be able to have a MERV 8 filter at least. The point of using a MERV 12 or higher filter is better indoor air quality (IAQ): cleaner, more breathable air for everyone, and especially for those with allergies, asthma, COPD, etc.
The Merv 16 would be the best, as it will filter 95%. There is a YouTube video showing how to make your own N95 with a Merv 16 filter. The MERV scale is not linear; the difference between a MERV 6 and a MERV 8 is almost double in the percentage of particles captured. A MERV rating of 13 to 16 is considered hospital-level air quality, so it's unlikely that your home will need more than that.
When you have a Merv filter 13 and higher, it's more similar to the material you'd find in an N95 dust mask. While ASHRAE recommends MERV 13 and 14, it's best to select a filter with the highest possible MERV rating for your specific HVAC system. While MERV 8 is known to be effective at filtering contaminants such as pollen, dust mites, sawdust, mold spores, and lint from the air, higher MERV ratings will clean the air even more. Ultimately, there is no price for peace of mind and if you feel that a high MERV filter would provide it, you should do so with the caveat that you should replace dirty filters often enough - which can be a week or two depending on the MERV rating, the effective area of the filter, and how many particles enter your house.
