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New 4.5 media filter box . Should I go with Merv 8 versus Merv 11 Filter have allergies ? Are the Merv8s to restrictive?I have allergies but don’t want to restrict air flow. Thanks
 

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Looking at the Merv rating charts the Merv 8 is the least restrictive.
And just to mention .... I run Merv 13 media in 5 GermGaurdian machines for tobacco smoke.
I doubt if Merv 8 or 11 would cause too much restriction.
 

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New 4.5 media filter box . Should I go with Merv 8 versus Merv 11 Filter have allergies ? Are the Merv8s to restrictive?I have allergies but don’t want to restrict air flow. Thanks
Generally, the higher the merv rating, the higher the air restriction. Merv 8 will catch quite a bit. Anything higher may or may not be to restrictive for your furnace /ac. If it's too restrictive, it can damage your equipment.

A high merv filter on your fresh air or HRV would help quite a bit.
 

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A middle of the road MERV 8 changed frequently (once a month) on a furnace will be kind to it. Many believe extend its service life. Static pressure is standard.
Higher end units have variable speed motors that adjust fan speed and consider restrictiveness of a filter whether it's getting dirty or is a higher MERV value to remove more stuff. May even sound louder if that's an issue.
Conclusion is that, if one must remove more stuff due to nonstandard conditions (ie allergies), life of unit could be reduced for that extra comfort.
Can't say same rules apply to small stand alone room filtration systems but any motor that works harder than necessary will likely have a shorter life.
 

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When the filter is 4 to 5" thick, you can safely go with a higher merv rating, but not always.

Just remember that the filter is only there to protect the equipment.
 

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WHO CARES what the filter will do? I am very serious about this.
The decision on filtering comes from the people who built your unit. As filtering does up so does static air pressure and air volume goes down.
So put in a MERVXX and throttle the air volume in your unit causing problems.
My idiot brother inlaw did this very thing and woke me up at 11 pm on a 100 degree night crying, no really crying. My sister was eating his lunch.
Your air filter is there to protect the unit. NOT TO CLEAN YOUR HOME.
If you want to clean you home get an whole house air cleaner.

I suggest you find your manufacture, model and look at the static air pressure tables. Verify what you unit is set to produce and make a decision from there. Higher Merv more restriction.
 
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