Air Heaters

When considering air heating applications, it's important to choose a heating system which works as efficiently as possible. Air heating as the target source is best done in confined areas so as the heated air isn't lost to the atmosphere. Hotco manufactures a wide range of air heaters, the majority of which, utilise finned tubular heating elements.

Finned Tubular Heating Elements

Finned tubular heating elements are the most common type of heating elements used in air heaters. The fins along the tubular length assist in even heat dissipation. All elements have mild steel fins copper brazed to the tubular heating element sheath unless otherwise specified. Available in either straight, U and mulitform shape, they are manufactured by Hotco as types AFH, FG and FH.

  • AFH are a lower watts density heating elements manufactured to Australian Standards. AFH finned heating elements are generally used in air ducts with forced drafts - or industrial process heating applications requiring heated air blasts.
  • FG are elements designed for forced convection air heaters. These heating elements are designed to operate at a black heat in applications where air velocity is in excess of 3m/sec (600fpm).
  • FH series heating elements are low watts density suitable for applications such as air ducts with forced air drafts and other industrial applications. Due to the low density, a tight construction can be achieved permitting large heater mass with lower power output.
Data AFH FGFH
Max Sheath Temp 400°C 400°C 400°C
Max Air Circulation Temp 200°C 200°C 200°C
Avg Watts Density of Sheath 46.5KW/m2 15KW/m2 65KW/m2
Min. Air Velcocity 1 m/s 1 m/s 1 m/s
Tubular Element Dia 11mm 11mm 11mm
Dia Over Fin 29mm 29mm 29mm

Specialised Air Heaters

Duct Heaters

Duct heaters consist of group of finned tubular elements fitted to a specified terminal box. The area with exposed group of elements will sit inside the duct chamber (mounted via the terminal box), the cold air passes over the finned elements heating the air. Ideally, for duct heaters to be effective air heaters - it is ideal to cover as much area of the duct with finned tubular heating elements in order to ensure that at some point in passing the group of elements, a large majority of the air must come into contact with the heated fins. Depending on the duct size, we generally group 'U' or 'M' shaped elements together ensuring they reach to the edges of the duct. They are offset in many cases to enable air gaps to be filled. A range of our common designs for air heaters are listed below.

Through the Wall Module 2.2Kw

An all stainless steel construction, through the wall modules are thermostatically controlled and feature over temperature protection. The 2.2 Kw model operates at 240V, 10A with a 3-pin plug connection. The unit fits into a 253mm x 253mm cut-out and is easy to install with 4 fixing screws.

Order Code Range °C Kw
GM25007 0 - 40 2.2
GM25008 40 - 100 2.2
GM25009 60 - 200 2.2
GM25010 30 - 320 2.2

Through the Wall Module 12, 15 & 18 Kw

In these modules, the fan and heater are in the same enclosure resulting in higher efficiency and faster heat transfer. Air flow of the units is 42 m3/min giving an average air temperature rise of 30°C and maximum air temperature of 200°C. The compact design takes up minimal space and the design is easily serviceable if required.

Order Code Description Kw
GM25011 Heater 12
GM25012 Heater 15
GM25013 Heater 18
GM24516 Control System 12-18


Hotco has an extensive range of stock air heaters and also custom-make heaters to specific requirements. As always if you need assistance in designing or selecting the right air or duct heaters for your application our team of technicians are available to assist.