Filter ratings and brands

[oldgoat]

I just had a new package unit installed that uses a 20 x 25 x 1 filter. Was going to us a washable one like I had in the old one then I found that washables are only a 4 merv or less and they recommended a 8 merv. I am thinking of between the 3M filtrete 300 or 600. The 300 has a rating that they say is a 7 merv vs the 8 merv for the 600. From what the charts say I don't see that much of a difference between the two and have read some that say 3M's are very restrictive which makes me lean more to the 300 series. Is there that much of a difference and are 3m more restrictive?

 

[JoshV]

Is this for a garage application? There is a difference between the merv ratings. Merv 8 isn't that high for indoor air filtration. I use a merv 16 in my house. If it is going to be in your garage the filter will just help to keep the ac components inside your air handler clean. The amount of air and dust that will come in when you open the garage door will most likely negate having a higher merv rated filter. The 3m filters do have a little higher pressure drop but the 1" filters will because they don't have as much media as a 2" or 5" filter.

 

[oldgoat]

No it is for the home, but the dealer was the one that said that I should use a Merv8 rating.

 

[pseudorealityx]

Typical commercial application is Merv 7 or 8.

I wouldn't go much more than that for a residential application unless it was planned for in the design... ie, a larger filter bed.

 

[JoshV]

If it is for the home I would go with the higher MERV rating and change the filter on a regular basis. It will help with the indoor air quality.