Indirectly.  Dry summer heat can mean more dust in the air.  Dust creeps into the house, and when the AC is running, some of it gets captured by the furnace filter. If a filter restricts proper airflow, the inside AC coil and line-set can freeze up.  Result?  The home doesn’t cool properly.

Is pulling the filter out and dusting it off good enough?  Mechanical Extremes’ Harold Wilkes says replacing your filter with a new one is a good investment, no matter the season.   So, how often?  In extremely dusty environments, change the filter as often as once a month, but at least every 6 months.

When you shop for filters, you should look for the best match for your furnace. Filters have Merv ratings which define the potential performance of the filter.  A filter with a higher Merv number will capture more, and finer, dust.  But be aware of this.  A larger number is not always the best solution. Harold Wilkes says “if the Merv rating is too high, it can suffocate the furnace.” That can lead to poor functioning and damage.

The recommended Merv rating will depend on your furnace. For a one-inch thick filter, a rating of 5 to 7 is about right. For 4-inch filters, 8 to 13 is appropriate. Best to check manufacturer specifications to find what’s right for your situation. If you have questions, or would like to transfer this worry to a professional, Mechanical Extremes can help. (517) 812-2484.