HVAC 

Duct heaters are used for air conditioning, heat recovery and ventilation systems as well as in process plants with a need for the heating of specific air types or gases.

In standard design types EFR and EFFK, at temperatures above 70°C, open air is required between duct and terminal box.

Special designs, type EFRS, EFF, EFFL and EFI.

Special designs are used for offshore and marine, among other things.

Duct heaters are also designed as ATEX-approved for explosion-proof areas.

EFFK

Electric duct heater designed for flange mounting in square ducts in connection with air conditioning, heat recovery and ventilation systems. The duct part is made from a hot-galvanised steel plate, the terminal box is integrated in the duct part and has IP22 density. The duct heaters are made of AISI 304 (stainless).

A thermal restriction device is embedded with automatic reclosing and a fire thermostat with manual reclosing. The duct heater is divided into groups - 3 or 4 depending on the power.

EFR

Heating unit for air heating systems, including supplementary heating for residential units or for other purposes in connection with ventilation systems.

The duct part is a round hot-galvanised steel pipe (spiro) with a rubber sealing ring in either end. The terminal box is made from an electrically galvanised plate equipped with sufficient fitting (IP44). The heating elements are made of AISI 304 (stainless). The terminal box includes a 1-pole thermal restriction device (30-87°C) with automatic reclosing and manual reset (125°C).

EFF

Special design of square duct heater for ventilation systems and process plants.

The duct part can be made from different materials on request. Hot-galvanised or stainless steel in different qualities/alloys. The terminal box can be made with different degrees of density from IP22 to IP66. The heating elements can be made of different types of stainless qualities. The choice of material is made based on which subject will be in contact with the heaters as well as the temperature inside the duct. For high-temperature heaters (max. 800ºC), incoloy 825 or incoloy 600 is used as piping material.

EFRS

Same as EFF, but for round ducts. For flange mounting or as spiro.

EFFL

Same as EFF, but with open air between the terminal box and the duct part. Used at temperatures above 70ºC inside the duct.

EFI

Inset duct heater designed for mounting inside existing ducts with air conditioning, heat recovery and ventilation systems. Or as duct heater in which the insert can be demounted without having to demount the entire duct.

The terminal box is equipped with a mounting plate with IP22 to IP66 density. The heating elements can be made of AISI 304 (stainless) or according to other requests. A thermal restriction device is embedded with automatic reclosing and a fire thermostat with manual reclosing.

General

All types of duct heaters can be made according to ATEX, Norsok 15138, DNV or other specifications/standards. For the application of UL requirements or doubts about the choice of duct heater and heating element materials, please contact us. We will be happy to give you advice.

Electric duct heaters must be connected to a temperature control device - see Controllers for Duct Heaters