No since the air is being pulled in from the duct and not from the confined space.
There is an arrow on one or more of lthe edges that indicates the air flow. Just aim the arrow in the proper direction (toward the furnace generally), and ur good to go.
If you were to compare this to Filtrete it would be slightly smaller. Filtrete is 14.81 x 19.81 x 0.81. Nordic Pure is smaller than the other two being 14.5 x 19.5 x 0.75 inches.
cancel wrong size
How dirty is your house/ Duct work / air ? How long are your blower run times? could clog in a week could last many months. Filters are design to hold a finite amount of particles, how fast depends on the enviroment it is in.
Arrows on each side should be pointing upwards if in the ceiling.
No, but if you open carefully you can slide one out and leave the other in the plastic film.
I am more along the lines of your service tech. He is suggesting that you will get more air to the unit, and thereby increase the efficiency of the furnace by allowing for more complete burning of the fuel.