David has been installing these large blowers which are supposed to push the air 50 feet high. The concept is to create an upward draft removing the cold air, that sinks to the ground, and replacing it with the warmer air above.
We are installing two in one of our Pinot Noir blocks – the block is about 20 acres. This is an experiment and if it works, even moderately well, we will install others. Our hope is that we wont have to test it and temperatures will not drop below freezing.
As water freezes, enclosing the grapes it gives off heat as it changes from liquid to solid. The problem is you have to keep pumping until it gets warm enough to melt the ice or goodbye the grapes.
Tall vertical fans work but they generally push the problem to your neighbor or another part of your vineyard. Helicopters really move the air but the hourly cost is astronomical. So, we are trying these horizontal blowers which can be powered by a tractor, are movable and don’t break the bank. (click images to enlarge)