Ventilation and heating control

The ventilation system is running all the time to keep the air fresh and the house healthy.  Stale air is extracted from the kitchen, utility room, downstairs loo, bathroom and shower rooms; fresh air is introduced into the main kitchen/living area, the front room, and all the bedrooms. The stale air is vented to outside through the wall, and fresh air is introduced from outside.  Heat is exchanged between the stale out-going air and the fresh in-coming air in the Genvex unit in the roof space at the top of the stairs.
The heat exchange unit contains air filters, which need to be changed at least annually.
There are no additional extractor fans from the bathroom or showers.  The steam is automatically collected by the ventilation system and the heat extracted and thus reused. 
The controller for the heating system is the black unit on the wall of the utility room.  The temperature displayed in the centre of the screen shows the current temperature of the overall house, as measured from the temperature of all the returning air reaching the Genvex unit.  In order to achieve a chosen comfort level, it is essential to keep all the windows shut and only open external doors as required.

The controller for the heating and ventilation system is shown at the top of this picture.
The controller allows you to set your preferred house temperature. We have initially set it to 19oC.  The top right button (beside the thermometer picture on the controller) raises or lowers the set temperature. The controller almost looks as though it has a touch screen, but actually you need to use the buttons beside the symbols.

If you want to boost the fan (for example if you are having a party, have burnt the toast, etc), use the lower left button (beside the lower fan picture) to increase the fan speed temporarily.  Press button once and a “1” will appear below the fan so it will boost for a period of one hour.  Press again for two hours and so on up to 9 hours and back to zero.
We have initially programmed the heating to be at the selected set temperature all day and 2oC lower at night between 2200 and 0600.  But this can be changed with up to 10 switching times per day (you don’t have to use all of them), with a fan speed, and a temperature difference from the set temperature.  Each day can be programmed individually if you wish.
If you are going away, simply lower the set temperature (button beside the thermometer picture on the main screen), and all the other temperatures follow from this.  It sounds as though it should be very easy to operate.
The heat in the house is recirculated continuously by the ventilation system via the heat exchanger.  Any additional heat required is supplied by an air source heat pump that is contained in the same Genvex unit as the heat exchanger.  The air source heat pump cuts in automatically when the air returning to the unit is below the temperature that has been set.
There is also more information available using the information button on the controller (lower right beside the i symbol), which lists other temperatures that might be of  interest:
  •        Supply air – the temperature of the air leaving the unit to supply the house
  •     Room – the temperature of the combined air from the house returning to the unit 
  •        Fresh air – outside air temperature
  •      Exhaust air – temperature of the air leaving the unit to be returned to outside
  •     Before evaporator – temperature of the stale air leaving the heat exchanger and entering cooling coil of the heat pump
  •     Evaporator –  the temperature of the cooling coil itself
  •     Extract air – temperature of the combined air from the house returning to the unit (same temperature as the “room” temperature above)
  •        Frost protection

1 Comment

Zulema Sennett

about 6 years ago

What an informative post! Dealing with HVAC systems is kinda complicated, so you better do it carefully and properly. I'm sure you covered everything about what others need to consider in their heaters, so I won't add any tips again. I just wish you'll continue to post more informative articles like this. Thanks! :)

Zulema Sennett @


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