Stakeholders

Designer

ENGINESA
info@enginesa.ad
architects and thermal engineering designer

Contracting method

Separate batches

Owner approach of sustainability

The goal was to have a building with passive house consumption, in Andorra with very low temperature in winter (-12ºC) for the first time.

Architectural description

Reformed building with 27 apartments, applying energy efficiency criteria.
It’s situated in an alpine zone.
The winter’s minimum temperature is -12°C.
Reduced heating consumption by 82%.
Acting on facade insulation and heating system: thermographic study, 15 to 20cm insulation, triple glazing LowE, blower door test, etc.

Building users opinion

Users are happy because their heating cost is very low and the comfort has increased.
Owner is happy too because he can grow up the price to rent the apartments, even if the users pays less than before (because the heating cost). He is happy too because he has a waiting list to rent their apartments.

Energy consumption

• Primary energy need : 5 kWhpe/m².year
• Primary energy need for standard building : 55 kWhpe/m².year

Primary energy needs

CEEB : 0.0001

• Final Energy : 130 kWhfe/m².year
Breakdown for energy consumption :

heating made by central heat pump. Consumption 4.5 kWh/m2/year
hoot water production by heat pump. consumption 21 kWh/m2/year
lighting 104.5 kWh/m2/year

• Initial consumption : 212 kWhpe/m².year

Envelope performance

• Envelope U-Value : 0 W.m^-2.K^-1
More information :

Primary facade, U=0.24 W/m2/K
Secondary facade U=0.34 W/m2/K
Facade to neighbor U=0.27 W/m2/year

• Building Compactness Coefficient : 3

n50

• Air Tightness Value : 2

Real final energy consumption

130

5

2 013

Systems

Heating system :
• Heat pump
• Water radiator
Hot water system :
• Heat pump
Cooling system :
• No cooling system
Ventilation system :
• Natural ventilation
Renewable systems :
• No renewable energy systems
• Renewable energy production : 100 %

Solutions enhancing nature free gains : solar gains control by blinds

Smart Building

BMS :

Control on/off, viewer of any parameter like temperatures, % opened of motorized valve, pump parameters (% velocity, flow, pressure, energy), instant and cumulated electrical and thermal energy consumption

facility controlled by a Desigo Insight central control by Siemens

Product

rockwool external pipe insulation 2x5cm each pipe

exterior pipe insulation

very good insulation with this thickness

daikin heat pump

Heat pump for heating low temperature (max 50ºC) and high efficiency COP between 2.84 to 3.77, ESEER 3.78.
It works at proportional temperature to outdoor temp to achieve always maximum COP.


We use with this heat pump, existing old radiators (high temperature and high emission) to heat this buiding after refurbishment, working at low temperature and low emission.

daikin altherma for DHW

High temperature heat pump to produce domestic hot water (DHW)

Produces low cost hot water. No problems

grundfos magna 3 for heating and DHW

Electronic pump with connection to BMS control system, data transmission: pressure (bar), flow (m3/h), instant consumption (W), cumulate consumption (kWh), thermal flow (kWh).
Working at constant temperature function (hot water production) or at constant pressure function (for heating facility)

Sometimes the pump stops without any order

Construction and exploitation costs

• Renewable energy systems cost : 35 000 €
• Cost of studies : 22 000 €
• Total cost of the building : 340 000 €
• Subsidies : 30 000 €

Urban environment

Building in Andorra la Vella down town, shopping zone

Land plot area

350 m²

Built-up area

100 %

Parking spaces

18

Building Environmental Quality