Power Calculation for Carbon Fiber Heating Elements

Simple Calculation Method for Drying Room Heat Power

Regarding how much heating power a drying room requires, I’d like to share a simple calculation method I’ve summarized. Since it’s simple, it may not be entirely precise, so researchers should not rely on this approach. This article is intended for those who plan to use carbon fiber heating elements to DIY drying ovens or baking ovens.

Let’s take one of our customers as an example. They originally used a combustion furnace (burning pellets or wood scraps). Due to environmental reasons, they wanted to switch to electric heating elements. The drying room walls were insulated with cotton, and the material being dried was semi-dry pine wood. The required drying temperature was to reach 80°C within 2 hours.

Basic Physics Knowledge (All parameters can be found via search engines):

• Weight = Density x Volume
• Heat = Power x Time
• Heat required to raise the temperature of an object = Specific Heat Capacity x Temperature Difference
• Specific heat capacity of wood: 1.72 x 10^3 J/(kg.K)
• Specific heat capacity of air: 1.003 x 10^3 J/(kg.K)
• Density of pine wood: 0.5~0.7 x 10^3 kg/m³, use 0.6 x 10^3
• Density of air: 1.29 kg/m³
• Volume: Assume wood fills 70% (this ensures the power calculation won’t be too low), air is calculated at 15 cubic meters
• Temperature difference: 90°C – 0°C (assuming winter low temperatures of 0°C)

Step 1: Calculate the Power Required to Heat the Wood

1. Calculate the weight of pine wood
   Weight of pine wood = 0.6 x 10^3 x 15 x 70% = 6300 kg
2. Calculate the heat required to raise the temperature
   Heat required = 6300 kg x (90°C – 0°C) x 1.72 x 10^3 J/(kg.°C) = 9.75 x 10^8 J
3. Calculate the power
   Power = 9.75 x 10^8 J / (2 x 3600 s) = 135450 W ≈ 136 kW

Step 2: Calculate the Power Required to Heat the Air

1. Calculate the weight of the air
   Weight of air = 1.29 x 15 = 19.35 kg
2. Calculate the heat required to raise the temperature
   Heat required = 19.35 kg x (90°C – 0°C) x 1.003 x 10^3 J/(kg.°C) = 1.75 x 10^6 J
3. Calculate the power
   Power = 1.75 x 10^6 J / (2 x 3600 s) = 243 W ≈ 500 W (the power required to heat the air can be ignored)

Step 3: Calculate Heat Loss in the Drying Room

Heat loss through insulation, metal components, and other factors is uniformly discounted by 15%.

Final Total Power Calculation

Total power = 136 kW x (1 + 15%) = 156.4 kW
A quick calculation method is that a drying room for wood requires approximately 10 kW per cubic meter of space.
If you use 1200W carbon fiber heating elements, you would need 130 units.

Additional Knowledge:

• Heat Conversion: 1 kilocalorie (kcal) = 4.1858518 kilojoules (kJ) (Quick calculation: kJ/4 = kcal)

GlobalQT specializes in manufacturing high-quality carbon fiber heating elements and quartz tube solutions. For more information, visit our website or contact us at contact@globalquartztube.com.