HDG Compact 100-200 (Wood Chip)

The HDG Compact 100-200 combines quality "made in Germany" with patented experience.

Log wood
Wood chips
Power levels: 100 kW, 105 kW, 115 kW, 150 kW, 200 kW
  • Inside view of the boiler







    1 - PLC control
    2 - Combustion chamber temperature sensor
    3 - Patented stepping grate
    4 - Automatic cleaning system
    5 - Lambda sensor
    6 - Automatic ash removal
  • Technical data



    Compact 105

    Compact 115

    Compact 150

    Compact 200

    Nominal thermal power (kW) 100 105 115 150 200
    Minimum thermal power (kW) 30 31,5 34,5 45 60
    Water capacity (l) 210  210  225 450 450
    Operating pressure (bar) 3 3 3 3 3
    Flue draught requirement (Pa)* 20/10 20/10 20/10 20/13 20/15
    Permissible flow temperature (°C) 95 95 95 95 95
    Flue gas pipe connection (mm) 250 250 250 300 300

    Dimensions and weight


    Compact 100

    Compact 105

    Compact 115

    Compact 150

    Compact 200

    Height closed without attachments (mm) 1583 1583 1583 1580 1580
    Width without attachments (mm) 1785 1785 1785 2203 2203
    Depth without attachments (mm) 780 780 780 880 880
    Weight (kg) 1540 1540 1585 2140 2220

    * Second value valid in conjunction with HDG flue gas cyclone with flue gas fan and negative pressure control.

Technology makes the difference

Made for (almost) every use

HDG is one of the first manufacturers to succeed in using the proven moving grate technology even in small combustion plants – the HDG stepping grate technology. The material travels through different temperature zones on the air-cooled and movable grate. In the process, it is dried, degassed and finally burnt. The constant movement of the grate elements reliably conveys combustion residues to the ash removal augers.

The air-cooled, moving stepping grate enables constant output even with different fuel types – in an adapted high-performance version, it is even suitable for base-load operation.

Extremely robust feeding system

The feeding system of the HDG Compact ensures that the fuel is continuously and safely conveyed onto the grate. The rotary feeder decouples the combustion from the fuel store and thus offers maximum back burn protection. The automatic reversing device prevents damage caused by foreign bodies. Due to the direct fuel input and the high-quality gear design, quiet operation with low energy costs is thus achieved.

Stepping grate for constant output at all times

The combustion grate is the decisive component in achieving optimum emission values. The stepping grate technology enables low-emission combustion with high efficiency – even with changing fuel properties. A high-performance stepping grate is optionally available for base-load operation.

Combustion chamber temperature sensor protects the boiler

The unique combustion chamber temperature sensor ensures steady operation in the optimum power range even with changing material and protects the components by limiting the combustion chamber temperature. Together with the lambda sensor, this also guarantees consistently low emissions.

Automatic cleaning system for ideal heat transfer

Vertical heat exchanger surface areas with a high self-cleaning effect, combined with cleaning turbulators as standard, ensure ideal heat transfer. For cleaning, the close-fitting and flat turbulators are moved to free the heat exchanger surface areas from flue ash.

Automatic ash removal as standard

Ash removal augers transport the ash into the 80-litre external ash containers. Here, the accumulating ash is compressed – this extends the emptying intervals. Ash bins with 140 or 240 litres capacity are also available on request.

Practical ash box with Euro interface

The new ash container with Euro receptacle from HDG can be transported directly with any standard tractor. The advantages: The mechanical drain saves time and money, the huge filling volume (230 litres) reduces the emptying intervals.

Absolute control

Individually controlled with a PLC control system

The control technology is the "brain" of every heating system. HDG relies on state-of-the-art electronics here – always reliable in operation and yet convenient to use: The PLC control technology

  • Optimised combustion with continuous adjustment of the air and fuel quantity
  • Power control between 30 and 100 percent
  • Accumulator management
  • Control of the automatic cleaning system and ash removal
  • Many options for adapting the system through individual programming of the control system
  • On request: HDG web visualisation and HDG Hydronic Plus as heating system controller

From the warehouse to the boiler

Robust delivery and feeding system for every application area

A sophisticated feeding system is crucial for the safe and reliable operation of an automatic wood heating system.

TBZ Transparent
  • 4-chamber rotary feeder: Combines absolute back burn protection with minimal component stress due to low friction surfaces
  • Automatic reversing device: Prevents damage from foreign objects by moving the rotary wheel back up to 3 times at a certain resistance
  • Stoker auger: Optimum fuel metering and direct input onto the combustion grate
  • High quality gearbox: Combines quiet operation with low energy costs and high power reserve

In addition, with several delivery systems for wood chips (flexi blade delivery system, hinged arm delivery system, walking floor delivery system, etc.) and pellets (suction system, auger delivery system), solutions are also available for fuel transport for every application.

  • "The fact that HDG has over 40 years of experience in the field of wood heating systems convinced us once and for all."

    Gert Unterreiner, Unterreiner Forstgeräte GmbH