Q: What's the difference between electric and hydronic snow melting? A: Energy Usage: Delta-Therm systems use energy on-demand while hydronic systems may have to maintain the water-glycol solution at 32°F to respond during a storm. System Efficiency: The U.S.D.E recognizes that electric resistance heating cables convert 100% of their energy into heat. The boiler(s) and distribution system used by a hydronic system are not 100% efficient. Boilers have efficiency ratings but check with the hydronic manufacturer on the distribution system. Routine Maintenance: The contactor panel switches are the only moving parts in an electric system. Hydronic systems use many moving parts to pump the water-glycol solution through the tubing and these parts require routine maintenance. Annual Testing: There is no annual testing with an electric system. Each hydronic tubing line needs to be balanced and pressure tested annually. Slab Heating: Electric system turn on at full power and immediately provide even heating across the slab. The farther the water glycol-solution travels from the boiler the cooler it becomes and melting may become uneven.