Ventilation – Allowing enough space
See also:
Form Factor
Thermal Bridge Calculations
Design – push the limits but not too far!
Reduced Embodied CO2
Windows and Overheating
The Architect’s Design Guide
A critical component in all passivhaus projects is the MVHR system. We are frequently sent plans that have reached a fairly advanced stage , some even post planning, where insufficient or no space has been allocated for the MVHR.
At the plant end these systems are bulky requiring enough space for the MVHR unit, distribution boxes and attenuators and space to service the machine – this requires space in front and to the sides. The Design Guide shows some typical dimensions required to fit the required system. The unit is best situated against an outside wall for maximum efficiency and should be easily accessible for servicing especially for the homeowner to change filters.
We specify radial ductwork rather than branched as these are easier to integrate into the building fabric and require fewer attenuators. We fully design the system for passivhaus requirements and to meet Part F. Contractors are provided with a 3D layout showing the routes and how they interact with the structure. Provision may have to be allowed for in the design for boxing to accommodate ductwork where this can not be fitted into floors or walls – for instance where a beam interupts the route. It is useful to design in a dropped ceiling in the plant room to accommodate the many ducts that start there.
