Soil and Concrete Heating/Curing
For soil heating in market gardens, golf greens or similar, the load demand is approximately 5 W/m2 / °C (0.26 W/Sq. Ft./°F). In other words to raise the soil temperature 1 °C or 1.8 °F, you need to install 5 W/m2. For soil heating of sports arenas, the load is normally 50 – 90 W/m2 (4.6 – 8.4 W/Sq. Ft.).
With soil heating in sports arenas you are able to prolong the green season and make the grass grow faster. You can keep the ground frost-free and melt some ice and snow.
Note: During heavy snowfalls the load selection as specified above will not be sufficient to melt all snow and ice. To have efficient snow melting you will need a standard snow melting installation with approximately 300 W/m2 or more of installed power.
Selection and location of heating cable as well as installation methods must be individually evaluated.
|Nexans Heating Cable for growing vegetables and planting in propagation beds. Cables are used for heating, moisture is provided by water atomizers.|
Drying and Hardening of Concrete
Electrical heating cables may be used for drying and hardening of concrete in new buildings. Hardening usually takes 7 – 10 days, depending on climate and temperature. By installing heating cables this time can be reduced.
The shortening of the drying time will contribute to the shortening of the complete construction time, which is economically advantageous. The heating cables are placed directly in the concrete. This prevents freezing and accelerates the hardening of the concrete and makes it possible to remove the frames after 72 hours even in severe cold. At a later stage, the heating cables can be re-connected for effective drying of the building structure and provide basic heating during the construction period. With rapid drying of the concrete the painting work can begin earlier than by using other heating methods.
Standard TXLP heating cables are often used for this purpose. Using a standard 230V element of 10 W/m connected to 400V is one possibility, giving an output of 30 W/m.
For drying and hardening of concrete, a load of 85 – 135 W/m2 is used. The cable is fixed to the armouring (reinforcement) mesh and should not cross or overlap at any point. The cable should not come in contact with plastic or combustible materials. The cables may be used at a later stage in the construction period and the cold leads are cut when the construction is completed.