15x9x1 MERV 8 Plus Carbon AC Furnace Filters 6 Pack spl_dlw When the RH in the

When the RH in the room has dropped at least 1%

This solid design includes valve

Measurements are clearly displayed on the LCD

Can be used as a pre-mix

Once all dust is removed the filter is good to be used again

15x9x1 MERV 8 Plus Carbon AC Furnace Filters 6 Pack spl_dlw When the RH in theNordic Pure Custom MERV 8 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition