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Is Solar Passive same as Passive House?

No, it is not.

Their principles.

The Solar Passive principles are based and dependent on using natural resources like solar energy and wind to the occupant’s benefit, but cannot confirm indoor conditions that will be achieved – it’s only best guesswork.

The Passive House principles are based on science to provide a pretty accurate performance outcome to create a constant comfortable and healthy indoor environment.

Passive House goes beyond

Under the Passive House method elements like building orientation, window placement, thermal insulation, winter solar gains and summer shading also play an important role.

However, thermal mass (for heating) and cross ventilation (for cooling), two of the major Solar Passive principles, have minor importance in Passive House.

Instead Passive House methods can be applied to all sites independent of their natural conditions as the focus is rather on the thermal performance of the building’s outer envelope and the provision of constant fresh and tempered air.

Importance of Performance and Consistency. Why?

Performance

Thermal mass is storing solar energy and distributes it back to the indoor environment – this is helpful in winter but mainly benefits the sun-affected parts of the building, not the southern oriented rooms. Mass can also absorb ambient heat to a certain degree and helps cooling the rooms in summer. All this is only useful if the outer envelope is well and continuously (without gaps) insulated to keep the gained heat or coolness inside. This includes the windows and doors.

Here the Passive House principles come into play using a tool to model the outer envelope’s heat losses and gains, and can therefore determine already at design stage if for example the planned insulation and windows are sufficient to achieve the desired indoor comfort. They also emphasise on sealing the building properly to avoid damage to the structure and performance loss to the insulation. In addition, Passive Houses have also an improved acoustic performance due to minimum double-glazed windows and heavily insulated walls.

Consistency

The Solar Passive principles require the occupant’s active involvement to open the windows for fresh air. Passive House standard also encourages to open the windows whenever possible, however, what about the ‘stinking hot’ summer days and the cold winter days? You would probably not want any windows or louvers open in those cases. Also, our busy lifestyle makes us forget about opening the windows at all and we end up spending most of our indoor time in stale and CO2 enriched air.

Here the Passive House ventilation strategy comes into play and still provides constant fresh air to a comfortable internal temperature range. As an additional benefit, outdoor pollutants like pollen, fumes and gases are getting filtered out before entering the house. Visit a Passive House and you will notice the better air quality straight away.