Mechanical Ventilation with Heat Recovery
What’s the point of Making sure your house is air tight and draught free and then punching 4 to 6 inch holes in the wall for ventilation. In windy weather your house will be over ventilated and cold and on still days it will be uncomfortable and stuffy. This is why the Passive House requires Mechanical Ventilation to ensure your house is constantly ventilated and healthy. Used and stale air is extracted from your kitchen and bathrooms. It passes through a exchanger in the central unit where its heat is ‘recovered’ and used to warm the cold fresh air supplied to bedrooms and living areas.
This not only makes your house extremely energy efficient but also a very healthy and comfortable place to be with a constant supply of fresh air. A MVHR system can be expensive and you can on average expect to pay between €4000 and €8000 for one. This cost however can be offset by the far smaller central heating system you will need to install.