The CR Box comprises four air filters commonly used in heating, ventilation, and air conditioning (HVAC); a cardboard base; and a box fan to draw air through the filters and toward the ceiling.

Check your current filter. The easiest way to find the size you need is to look at the filter that's already inside of your ...

The CR Box is made up of four air filters commonly used in heating, ventilation, and air conditioning (HVAC); a cardboard ...