Passive Schools

In a Passive School the heat from 25 pupils and a teacher (1.5kw) is enough to keep the classroom comfortable for the whole year. Due of the success of the earlier Passive Schools every new School in Frankfurt will now be built to Passive Standards.

I believe that Global warming awareness is best taught from an early age and children who study in a Passive School will have a much lower Carbon footprint in later life. If the backup heating fails for a few days a highly insulated Passive School will never get colder than 17-18 degrees and because of the Triple Glazing the seat near the window is always comfortable.

The high level of heavy insulation guarantees a comfortable indoor climate throughout the year. Using very little energy, the school stays warm during the winter and cool during the summer. The walls floors and roofs of the Passive Schools have been insulated to 0.15 or better with Triple glazed (0.8 U-value) windows. Airtightness results as good as N50=0.26/h have been achieved which is 40 times more airtight than the minimum air leakage allowed under the new Part L regulations due out in July 08. All Cold Bridges have been eliminated in the Construction Phase.

Heat Recovery Ventilation was installed to minimise energy losses through ventilation and to ensures that the pupils get plenty of fresh air to keep them sharp and alert while at school. This also ensures that the school is kept healthy and fresh with no mould or fungus growth arising from condensation of moist air on cold surfaces. HRV guarantees superior air quality and low CO2 levels without the need to open the windows, creating a well ventilated and quiet learning environment that also supports the pupils health.

The payback period for passive house technology in schools is usually less than 15 years. Some passive house schools in Germany did not incur any extra costs at all. The payback period for one Passive schools was thought to have been 38 years in 2003 but with the increase in the price of Oil this payback period was reduced to 12 years in 2005 and should be much less now with Oil reaching $130/barrel. This will result in savings of several thousands per year after the payback period.Irish Schools built using the traditional method will cost more to heat over the next 25 years than they origionally cost to build.

The passive house concept cuts a school building's heat demand by up to 90 per cent, providing reliable protection against rising energy prices. Money otherwise spent on heating can be invested in education.

The city of Frankfurt, Germany, seat of the European central bank and Germany's main business hub, decided in 2007 that with immediate effect all schools and daycares and all official buildings have to be built and, if economically feasible, renovated to the passive house standard.

Riedbergschool, Frankfurt

Basic Facts

Opened in : 2004
Area : 8,000 m²(6,300 m² + gym)
Occupants : 650 - 675
Construction type: concrete
Ventilation : three vent. centres
Heating : wood pellets stoves
Air tightness: n50=0.46/h
Extras: 30 kW photovoltaics

Riedbergschool, Frankfurt

energetic performanc

Calculated heat demand : 15 kWh/(m²a)
U-value walls : 0,17 W/(m²K)
U-value window frames : 0,8 W/(m²K)
U-value glazing : 0,6 W/(m²K)
U-value roof : 0,11 W/(m²K)
U-value ground slab : 0,21 W/(m²K)

The internal Winter temperature was between 19.5 and 20.6 °C.
Almost no summer overheating occured, the average in 2006 (warm summer) was 22.9 °C.
The CO2 concentration was almost always under the recommended threshold of 1,500 ppm.
The heat consumption during the winter of 2005/06 was 90% below the average German School.

Cost

Total : 16.7 mio £
Additional costs : ~ 5 %
Construction costs : 1,110 £/m²
Est. payback period in 2003 : 38 years
Est. payback period in 2005 : 12 years

With oil prices hitting 130 $ / barrel payback period is even shorter today.

After payback period energy savings of several thousand euros per year.

Heinrich v. Kleist school, Frankfurt

Basic Facts

Opened in : 2007
Area : 1,338 m²
Construction type: extension, concrete
Ventilation : Wolf KG 160 Gigant
Heating : shares heating with existing building
Air tightness: n50=0.24/h
Extras: green roof insulation is CFC-free

Energetic Performance / Costs

Calculated heat demand : 14 kWh/(m²a)equals 1.4 liters of oil per square meter per year
U-value walls : 0.126 W/(m²K), mineral fibre insulation
U-value window frames: 0.81 W/(m²K)
U-value glazing : 0.6 W/(m²K)
U-value roof : 0.095 W/(m²K)EPS insulation
U-value ground slab : 0.144 W/(m²K)EPS and foam glass
Total costs: 2,692 £/m²
Construction costs: 2,053 £/m²

Schwanheim daycare, Frankfurt

Basic Facts

Construction time : 08/2005 - 10/2006
Area : 775.97 m²
Occupants : 80
Construction type : timberframe
Ventilation : MHRV,81 % heat recovery, Heating condensing gas boiler
Air tightness : n50= 0.6/h
The building is divided into three zones:
North: Service functions (less sunshine)
Middle: access to first floor as play street
South: group rooms (large windows, sunny)

Energetic Performance / Costs

Calculated heat demand : 15 kWh/(m²a)equals 1.5 liters of oil per square meter per year
U-value walls : 0.114 W/(m²K), cellulose and wood fibre insulation
U-value window frames: 0.81 W/(m²K)
U-value glazing : 0.6 W/(m²K)
U-value roof : 0.091 W/(m²K)EPS insulation
U-value ground slab : 0.139 W/(m²K)foam glass
Total costs: 2.65 mio £, 3,357 £/m²
Construction costs: 1.07 mio £, 1,360 £/m²

Altkonigsblick daycare, Frankfurt

Basic Facts

Completed in : 2007
Area : 919 m²
Occupants : 26
Construction type : timberframe
Ventilation : mechanical heat recovery ventilation 80 % heat recovery
Heating : district heating
Air tightness : n50= 0.4/h

Energetic Performance / Costs

Calculated heat demand : 15 kWh/(m²a)equals 1.5 liters of oil per square meter per year
U-value walls : 0.106 - 0.146 W/(m²K)
U-value window frames: 0.73 - 1.0 W/(m²K)
U-value glazing : 0.6 W/(m²K)
U-value roof : 0.069 W/(m²K)
U-value ground slab : 0.124 W/(m²K)
Total costs: 2.08 mio £ / 2,270 £/m²
Construction costs: 1.41 mio £ / 1,538 £/m²
Calc. payback period (2007): 11.6 years

Preungesheim primary school, Frankfurt

Basic Facts

Construction time : 05/2006 - 08/2007
Area : 5,152 m²
Occupants : 530
Construction type : concrete
Ventilation : MHRV 77 % heat recovery
Heating : wood pellet stove
Air tightness : n50= 0.5/h
Primary school, daycare, youth center and gym

Basic Facts

Construction time : 05/2006 - 08/2007
Area : 5,152 m²
Occupants : 530
Construction type : concrete
Ventilation : MHRV 77 % heat recovery
Heating : wood pellet stove
Air tightness : n50= 0.5/h
Primary school, daycare, youth center and gym

Energetic Performance / Costs

Calculated heat demand : 15 kWh/(m²a)equals 1.5 liters of oil per square meter per year
U-value walls : 0.13 W/(m²K)
U-value window frames: 0.8 W/(m²K)
U-value glazing : 0.6 W/(m²K)
U-value roof : 0.092 W/(m²K)
U-value ground slab : 0.133 - 0.164 W/(m²K)
Total costs: 21,85 mio £
Construction costs: 1.41 mio £ / 1,538 £/m²
Calc. payback period (2008): 16.3 years