night and day ventilation Specification Validation Conclusion
Realisation of the first prototype
The basic idea behind the breathing window is a smart individual ventilation, which has almost all qualities of the larger centralised ventilation systems and little disadvantages. It is no hopeless mission to re-design and minimalise all parts of this ventilation system. It is my personal opinion that a solution at micro scale can always be realised.

Five aspects are crucial:

  • very high heat-recovery efficiency from the used ventilation air;
  • extreme indoor and outdoor static air pressure differences;
  • smart control in all parts of the world;
  • customer friendly / hygienic aspects;
  • low purchase and maintenance costs.

    The worldwide search for the best heat exchanger in literature took years and to my great surprise ended on a website fine-wire heat exchanger designed by someone who lives 40 kilometres away from where I live.

    		• The inventor, dr ir Noor van Andel needed a few months to convert the original water/air heat exchanger into an air/air heat exchanger. (He received an honorary doctorate of the University of Amsterdam for his oeuvre in 2001).

    Being preoccupied by the name breathing window, I chose the measures of a window frame with a depth which is standard for the (Dutch) cavity wall + insulation of a traditional outside brick wall.

    The breathing window consists of three main components:

  • balanced mechanical ventilation,
  • smart control system, and
  • fine-wire counter current heat-exchanger

    The prototype became a compact transparent synthetic counter current heat exchanger 150/220/500 mm, composed of 15 km (length) 0,1 mm (diameter) copper wires, altogether weighing less than 1 kilogram. The weaving of the prototype on a washing drum however took three days.