The primary purpose of Tank Warmer is to sustain the warmth within the tank, similar to a coffee thermos. Keeping the core of the tank warmer longer, permits greater use of the gases inside. The photo above depicts a 72F tank being frozen to near zero degrees. Thirty minutes later, the core of the tank remained 33.4F. More important, tanks with less than 1/3 gas remaining freeze quicker. Once warmed, the user will consume 100% of the remaining gas. Our testing has shown that a warm tank runs heaters longer than a frozen tank.