What is electric duct heater?
What is electric duct heater?
electric duct heater which makes use of electricity to warm the air that passes through a duct. It consists of a heating element which converts the electricity into heat through resistance. The resulting heat is transferred by conduction or convection to the air passing through the device.
Why do we use duct heaters?
Duct heaters are ideal to warm low-pressure air flow via convection heating. For cold and humid environments, the air flowing temperature of the duct will gradually decrease across the duct wall. For this case, an air duct heater would be useful to supply the required heat in order to warm the building.
What is inside a heating element?
Metal heating elements generally are made from nichrome, which is composed of 80% nickel and 20% chromium. Nichrome 80/20 make great heating elements because the material yields a pretty high resistance.
Which element is used for heating?
The most common material used for the heating element is Nichrome. Nichrome is the alloy of the Nickel and chromium; in this alloy the nickel is 80% and the chromium is 20%.
How does duct heater work?
The most common type is the electrical duct heaters. They create heat while passing an electric current through resistance (coils). The air passing through absorbs the heat out of the coils and it is then pushed through the ductwork into your rooms. This makes inline electric heaters highly energy efficient.
How do you control a duct heater?
Standard Control Options for Electric Duct Heaters
- Automatic and manual reset thermal cutouts to protect against overheating.
- A differential pressure airflow switch to de-energize the heater control circuit upon loss of airflow.
- De-energizing magnetic contactors for each heater stage.
How do I know what size duct heater I need?
Face Area = ((H”- 2.5”)(W” – 0.5”))/144 in2/ft2 = ((12” – 2.5”)(24” – 0.5”))/144 in2/ft2 = 1.53 ft2 kW/ft2 = kW of heater/Face Area = 25/1.53 = 16.3 kW/ft2 From the Open Coil Elements chart (see above), a Heater Face Area of 16.3 kW/ft2 shows a Minimum Air Velocity for 81°F maximum inlet air temperature air to be 700 …
What is duct in civil engineering?
Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, supply air, return air, and exhaust air. Ducts commonly also deliver ventilation air as part of the supply air. A duct system is also called ductwork.
How do I know if my heating element is bad?
Touch a probe on the multitester to each screw on the element. If you get no reading, or a maximum reading, the element is bad. Elements do have some resistance, so a reading of 10-16 ohms is normal, with higher ohm readings for 3,500 watt elements and lower readings for 5,500 watt elements.
What makes a good heating element?
The most important heating element characteristics are sufficient resistivity, high oxidation resistance, low-temperature coefficient of resistance, high toughness, and high melting point. Widely used heating elements are nickel-chromium alloy, iron-chromium-aluminum alloy, molybdenum disilicide, and silicon carbide.
What are the causes of failure of heating element?
Causes of Failure of Heating Elements:
- The main causes of failure of heating elements are given below:
- Formation of Hot Spot:
- Contamination and Corrosion:
What can a duct heater be used for?
Air duct heaters are primarily used in air flowing ventilation systems and comfort-heating applications while process duct heaters are mainly used for industrial process heating applications (ovens that require re-circulated air or forced circulation). WATTCO™ designs and configures your electric heating element according to your specifications.
What kind of duct heater does wattco make?
Since 1969, WATTCO™ has expertise in developing and manufacturing electrical heating elements that make Wattco duct heaters, the most easily adaptable industrial heating solution for most non-pressurized, air-heating systems. A broad range of custom-built electric duct industrial heaters with capacities up to 1000kW is available upon request.
What’s the capacity of an electric duct heater?
A broad range of custom-built electric duct industrial heaters with capacities up to 1000kW is available upon request.
How does an electric duct heater step controller work?
Electronic Step Controller An electronic step controller provides electronic sequencing control of an electric duct heater up to 12 steps. When interruption of power occurs all stages cycle off. Upon restoration of power the step sequence resumes.