Zero Energy Building Example in Estonia Tõnu Mauring University of Tartu, Estonia Jan 22 2014, Riga
Site location Põlva, Estonia (58 N, 27 E) Long-term average dry bulb temperature for inland part of Estonia is in: December -2,5 C, January -3,0 C, February -5,2 C. [Kalamees and Kurnitski 2006] [Kalamees and Vinha 2004] Corresponding long-term average daily minimum values are from November to March below -10,0 C, For January below -14,3 C. Temperature falls Occasionally below -30,0 C, Frequently below -15,0 C [Kalamees 2006] [Estonian Meteorological and Hydrological Institute 2002]
Monthly average ambient air temperature
Sunshine duration hours in month
Sunshine duration
Põlva, Estonia
Architects Martha Enriquez Reinberg and Georg W. Reinberg Treated floor area (PHPP) 280,6 m 2 Number of rooms 6 Construction time 2012-2013 Mixed wood and concrete
Thermal envelope Wall 400 mm cellulose fiber, 94 mm KLH Massive wood, U = 0,105 W/(m 2 K) Ceiling 500 mm EPS, 102 mm KLH U = 0,079 W/(m 2 K) Wall, underground 500 mm EPS, 200 mm concrete U = 0,066 W/(m 2 K) Floor 300 mm XPS, 300 mm concrete, 100 mm EPS U = 0,086 W/(m 2 K)
Wall construction U = 0,105 W/(m 2 K) Ψ -0,046 W/(mK) THERM 7.1 THERM 6.3
Wall construction U = 0,105 W/(m 2 K) Ψ -0,014 W/(mK) THERM 7.1
Window SmartWin fixed U frame 0,57 W/(m 2 K) ψ spacer 0,026 W/(mK) ψ installation 0,010 W/(mK) SmartWin opening U raam 0,77 W/(m 2 K) ψ spacer 0,026 W/(mK) ψ installation 0,010 W/(mK) U glas 0,54 W/(m 2 K) g-value 0,50
Window Outside insulation Ψ = 0,014 W/(mK) SmartWin Ψ = 0,050 W/(mK) Comparison: not insulated
Ventilation unit Paul Novus 300 Heat recovery 93% (PHI def) Paul Sole Defroster SD-550, 226 m long 40 mm pipe
airtightness n 50 = 0,31 h -1
Heat loss and heat gains in kwh/month Building heat balance in kwh/month 3500 2500 1500 500-500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec -1500-2500 Net space heat demand Utilised internal heat gains Utilised solar gains Non-utilised internal heat gains Non-utilised solar gains Heat losses PHPP 2007, ISO 13790
Heat losses and gains in heating period in kwh/a Exterior Wall to Ambient Exterior Wall to Conservatory Exterior Wall to Ground Roof to Ambient Floor slab Windows (incl. thermal bridges) Exterior Door Linear thermal bridges (external dim.) Ventilation and infiltration Utilised solar heat gain Utilised internal heat gain Annual net space heat demand Building heat balance in kwh/a 7000 6000 5734 5000 4000 4044 3000 2000 2365 1000 0-3073 -311-367 -1064-681 -5706-278 546-1210 -1000-2000 -3000-4000 -5000-6000 -7000 PHPP 2007, ISO 13790
Window heat balance in kwh/a Heat losses Utilised solar gains Non-utilised solar gains West South East North -4000-3000 -2000-1000 0 1000 2000 3000 4000 5000 6000 7000 Heat loss and gain for the heating period in kwh/a PHPP 2007, ISO 13790
2 x 1000 L Solar thermal system, calculated annual production 4900 kwh
12 m 2 roof integrated solar thermal collectors for warm water Sonnenkraft SK IMK
separate array of solar thermal collectors 13 m 2 for heating and warm water integrated to southern façade and optimized for the winter operation
Ground source heat pump Viessmann Vitocal 300 G BWC 5,9 kw COP = 4,5 2 x 80 m deep vertical boreholes
Wall heating 2 x 1000 L 39/33ºC supply/return temperture
Summer night ventilation
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 Space heating + warm water heating balance in kwh/a Calculated values Net space heating demand Production Heat pump Solar thermal Losses of space heat distribution (non-utilised) Demand Space heating DHW DHW losses Net energy demand for domestic hot water (DHW) production Losses of DHW storage and distribution (non-utilised) Energy demand and production (kwh/a) Energy demand covered by GSHP (vertical ground source heat pump) Useful energy production by solar-thermal system for space heating and DHW
Aim: net zero energy house 90 m 2 PV panels SolarWorld Sunmodule Plus SW 196 Vario poly Calculated annual production of the system 10 120 kwh
Electricity kwh/a Electricity demand and production in kwh/a 12000 Calculated values: 10000 Photovoltaic 8000 6000 4000 2000 Domestic appliances, lighting, sauna equipment etc. Technical installations (ventilators, pumps etc.) GSHP (vertical ground source heat pump) 0 Demand Production
Calculated electricity demand heat pump household auxilliary 10 360 kwh/a Calculated PV electricity production 90 m 2 SolarWorld Sunmodule Plus SW 196 Vario poly Calculated production: Balance 0 10 120 kwh/a
electrical energy in kwh 1800 1600 Measured values in 2013 PV generated grid traffic Sold to grid Bought from grid 1400 1200 1000 800 Sold to grid Bought from grid 600 400 200 0 July Aug Sept Okt Nov Dez Sold to grid (blue) Bought from grid (red) July 1369 398 Aug 1283 482 Sept 1022 428 Okt 434 895 Nov 54 1062 Dez 20 1535
Monitoring Window and door position sensors (4) for night cooling and CO 2 Indoor air temperature and humidity sensors (6) for indoor climate on all floors and different room types CO 2 (2) for indoor climate in two bedrooms Massive wall temperature sensors (12) for temperature on different sides and heigths of wall Ventilation system (including defroster) temperature and humidity sensors (5) Outside air temperture and humidity sensors Wall construction temperature and humidity sensors (5) Wall heat flux sensor Global radiation sensor
Temperature cource in massive wall regular temperature increase 7 K in 6,5 hr due to passive solar no additional heating in March 2013
Measured indoor air relative humidity % 1 st floor bedroom 50% 30% 1 month period: Aug 24 to Sept 24 2013
Measured indoor air CO 2 concentration 1 st floor bedroom 1000 ppm 400 ppm 1 month period: Aug 24 to Sept 24 2013
Thank you! Parties involved in the project: Architects: Martha Enriquez Reinberg and Georg W. Reinberg, Architekturbüro Reinberg ZT GmbH, Wien, Austria. Consulters: Tõnu Mauring, Jaanus Hallik and Kristo Kalbe, University of Tartu (building physics, monitoring), Johannes Riebenbauer, Graz (static engineer), S&P Climadesign GmbH (technical systems), Margus Valge, Sense OÜ (project management and site supervision), PassiveHouse OÜ Estonia and Passive House Institute Darmstadt (certification).