Changing to Hot Weather Mode

HEG Air Circulation System users.. with the hot weather in Tasmania, ensure that you configure your system to enable you to keep cooler. These instructions are for two different models of controllers, and allow you to distribute cooler air without adding hot air from the roof cavity:

HEG Digital thermostat with a red LED display

Simple method

  1. Switch off the LED display by holding your finger on the power button for three seconds; ensure that the FAN switch is still switched on. Air from cooler parts of the house or an air conditioner will be distributed around the home, but the Roof Heat Recovery Module has been disabled.
    [End of instructions for the Simple Method].

Advanced Method

  1. With the controller display on, hold your finger on the SET button for 4 seconds until the display says "HC" (Hot or Cold weather mode), then press the Down arrow until the screen display indicates "H" for "Hot Weather". 
  2. Leave the controller for 10 seconds until the screen reverts back to the regular screen. In Hot Weather mode, the filtered air intake in your roofspace will automatically suck air into your home only when the air in the roof is cooler than the "Set Temperature".
  3. To change the Set Temperature, press the SET button quickly, then use the Up and Down arrows to adjust the temperature setting. Leave the controller for 10 seconds, and the setting will automatically save, and the screen will revert back to the Home screen. 
  4. Note: when the air temperature in the roof is below the trigger temperature by a degree or two, cooler air will automatically be introduced into the house; similarly, when the roof temperature starts to warm up, the air intake in the roof will stop introducing air.

HEG Manual Controller

  1. Switch the HEAT switch off, but leave the FAN switch on. This will enable you to distribute air (e.g. from a well-ventilated living room or with air conditioned air) and the Roof Heat Recovery feature is disabled.

Instructions for HEG DC-02 Air Circulation System Controller

HEG DC-02 Controller for HEG Air Circulation SystemController Model: HEG-DC02 (pictured), Author: Adam Hirst, version 01

HEG Air Circulation™ is a hybrid heat transfer system specifically optimised for the Tasmanian climate and market. HEG Air Circulation allows residential dwellings to:

  • Have a healthier environment for residents due to improved air quality;
  • Lower heating costs due to solar roof heat recovery & minimisation of secondary heaters;
  • Achieve better distribution of warm or cool air around bedrooms & hallways;

HEG Air Circulation System Explained

The base system is comprised of a powerful air transfer system, called the HEG Air Circulation System. It is designed for long-term operation, often working 24/7 for 9 months per year during cooler months, with many customers keeping it in continual operation. The system continually circulates large volumes of warm or cool air to affect the remainder of the house. Whilst this circulation effect is occurring, solar gain through windows in rooms can be used to informally heat the rest of the house, resulting in very balanced air temperatures.


Jet Inlet - the standard inlet for the HEG Air Circulation System Bedroom outlets - full cone nose diffusers

ABOVE: The standard living room ceiling inlet, at left, and a picture of the bedroom outlet, at right.

BELOW: A diagram showing the main thermal flows and features of a HEG Air Circulation System.


Other modules are added to provide functionality, as follows...

Roof Heat Recovery Module

Most systems are fitted with a Roof Heat Recovery Module (item 3 in the daigram, above), which is a filtered intake in the roof space which allows solar gain from the roof cavity to supplement traditional heaters in the household. The roof space intake has a motorised, filtered air valve that opens when the air in the roof space is over a specified trigger point. This trigger point, or temperature, can be adjusted by the customer, which is a useful thing to be able to do as requirements vary from house to house.

The image of the controller, at top of the first page, shows a temperature of 23 degrees in the roof space (NOTE: It does not show the room temperature). The trigger temperature is usually 20 degrees or above, which means that the Roof Heat Recovery Air Valve will open when the roof space air temperature reaches that temperature, or higher. When the roof heat recovery module is active (meaning that the roof heat recovery valve is open), you will notice a small red indicator light to the left of the temperature readout.

To turn the Roof Heat Recovery Module ON or OFF

Hold you finger on the power button on the thermostat for 3 seconds. When off, the temperature display will disappear.


To change the Trigger Temperature*

*This is the temperature when the Roof Heat Recovery filtered intake starts taking air from your roof cavity i.e. when a certain roof air temperature is attained.

Click the SET button, and then press the UP or DOWN arrows to adjust to the desired trigger temperature. To save the setting, simply leave the thermostat alone for 15 seconds and the screen will revert back to the temperature screen. Standard setting is 19 degrees.

Hint: hold you finger down on the SET button for 3 seconds if you don’t want to wait for the 15 seconds.



Condensation Control Module

This module allows drier, fresh air to be mixed and circulated with the internal air of your home. Outside air is generally quite a bit drier than internal air, so humidity levels are reduced due to dilution of moist air (and subsequent displacement of humid internal air out of cracks in the house structure).  Filtered air is brought in via an intake on your eaves, gable ends or via a roof vent/cowl, whichever is most relevant to your house (depends on construction characteristics). The vents need to be cleaned monthly or more frequently when the system is in continual operation, and full instructions can be found here:

Filtered Ceiling Inlet

Our usual ceiling inlets are usually a “Jet Diffuser” style, which is made up of rings of concentric circles. An optional extra is the filtered inlet, which stops dust particles from entering the system. These dust particles are already in your house, so it provides a degree of dust removal, similar to an air conditioning system. The filter cartridge can be accessed by hand unscrewing the bolt at one edge of the filtered intake. The filter needs to be cleaned frequently, and changed every two years.

Filtered ceiling inlet

Operational recommendations

    • 24/7: Leave the system running all of the time during cooler months with the Roof Heat Recovery Module permanently on.
    • Use the system without the Roof Heat Recovery Module during summer to duct cooler ventilation or cool air from air conditioners.
    • The filter sock on the Roof Heat Recovery Module can be DIY cleaned once per year using a vacuum cleaner, but needs to be replaced every 2 years. See HEG for DIY or professional maintenance servicing.
    • Filtered Inlet: The intake for the HEG Air Circulation System is usually a filtered grill, which has filter cartridge located just above the grill. This can get clogged with dust, hair and other particles over time. HEG suggests cleaning this monthly, or more regularly if a whistling sounds is present, indicating that the filter is becoming blocked.

HEG Energy - Home Efficiency GroupHome Efficiency Group
Local Call Fee: 1300 96 80 60
285 Invermay Road, Invermay TAS 7248