bulk tank vents

[nymapleguy607]

Hey everyone, I was wondering if any of you have some type of vent on your bulk tanks to let warm air out. I went to a class at Verona and they recomended open top tanks because the allowed the sap to cool back down after it comes out of the tubing. I usually cover my tanks with a tarp but I was thinking about adding a piece of 4" duct pipe through the center hole on the tank and putting a cover at the top so it might help keep the sap cool. What do you think?

[markct]

my experience with my zero tanks has been that the sap was as much as 20 deg warmer than the outside temp on sunny days, i changed to blue mainline from black and have never seen more than 5 deg difference, usualy less

[ennismaple]

Build a frame to hold the tarp out of 2x4's. By creating an air space above the top of the tank you allow cooler air to circulate through.