Comming from a very cold climate I can tell you that in the dead of winter with temperatures hovering at -30C during the weekend when there is very little demand on the system the fans actually shut off and condenser pressure sometimes drops to 70 psig. We use fans first, pumps second with the pumps not comming on until we get over 110 psig and the fans shut off at 80 psig and don't come back on till we have 90 psig. The fans are on VFDs. In real cold climates a small water leak in your condenser becomes a giant ball of ice on your roof pdq.