I atone time did not think it was making a difference but have changed my mind. The last 2 winters have been really extreme in zone 3-4 and the single fans I received I tried to really plump up before winter but I have lost more of them or were slow to increase VS dble triple fans. I have gotten singles this past season and I request Dble fans instead of a bonus so I hope that is what I get in the spring.
