Air sealing and ventilation

The airtightness is neat because it must reach less than 0.6 air changes per hour under a pressure of 50 Pascals. The slightest leak must be hunted and eliminated.

The reason is that such leakage may disrupt the operation of the heat recovery ventilation and create ventilation short circuit resulting in poor recovery of the heat exchanger by the ventilation and a poor air quality ( see odors in normal houses with ventilation if we do not open the windows. So as paradoxical as it may seem, a very good airtightness of the house will allow better air quality by allowing the ventilation to operate in better conditions.

Different ventilation's items were purchased and installed by me. Filters to limit costs and to increase efficiency and eliminate the clogging of pipes, I created the boxes in the walls at the input / output grids (30x30cm). So I could accommodate a large enough G4 filter (to prevent the entry of insects), a large G4 and F7 filter at the input and G4 filters on each extract hole. It is very easy in this case to cut filters to size and buy wholesale filters. The cost is greatly reduced. An advantage to split the filters on the extract holes is that we have large filtration area that reduces the frequency of change and a smaller electrical consumption because the air is less hindered. I obviously removed the built-in filters in the ventilation unit.

The ventilation unit is controlled by an air quality sensor that detects the amount of VOCs. This probe is connected on the ventilation unit and automatically varies the fan speed.

This reduction in fan speed reduces heat loss in winter (and limit the warming of the house in summer) while reducing energy consumption.

3kW hot water heating heat exchanger is present in the ventilation circuit as the main heating and heats the whole house via the ventilation network. In reality there is no 3kW of heat output which is transmitted to the air because the ventilation unit automatically varies the speed. I set the cut-off temperature to 21 degrees Celsius and the start-up temperature to 20 degrees Celsius, and the temperature varies between 19.5 and 22.5 degrees (overrun operation) with an average of 20 degrees. During the autumn I did not need to heat (23 degrees) while many of my acquaintances had lit the wood stove or fireplace.

The photo below shows the ventilation unit on the wall, the water heater on the ground and the heat recovery of greywater in the small pit.

The photo below shows input / output ventilation pipes embedded in the insulation.

The photo below shows the ventilation with the air intake box to install a large filter.