Heat Calculations

When determining the amount of power required for a particular furnace or application, AVS considers two aspects, ramping power and holding power. Ramping power is the amount of power necessary to heat an amount of material at a particular rate. This is a straightforward calculation using the customer’s desired ramp rate, the weight of the load, and the specific heat capacity of the material being heated. In addition to the product and any tooling used, the materials and weight of the heaters and hot zone assembly must also be accounted for in this calculation.


The consideration of holding power is often overlooked by other furnace manufacturers. Over its 40+ years, AVS has built hundreds of furnaces. Every furnace is tested at AVS before shipment and power use under various temperatures and atmospheric conditions are meticulously documented. Based on this collection of empirical data, AVS has developed an algorithm that accounts for the heat losses from a furnace through the insulation package or by the convective behaviors of various gases at various pressures.


The sum of these two heat components is what AVS uses to ultimately size its furnace power supplies. By making the effort to fully understand your objectives, AVS furnaces are always able to ramp your maximum product loads to maximum temperatures at the desired ramp rates.