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]

Corresponding long-term average

daily minimum values are from

• November to March below -10,0 °C,

• For January below -14,3 °C.

[Kalamees 2006]

Temperature falls

• Occasionally below -30,0 °C,

• Frequently below -15,0 °C

[Estonian Meteorological and Hydrological Institute 2002]

[Kalamees and Vinha 2004]

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 m2

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/(m2K)

Ceiling

500 mm EPS, 102 mm KLH

U = 0,079 W/(m2K)

Wall, underground

500 mm EPS, 200 mm concrete

U = 0,066 W/(m2K)

Floor

300 mm XPS, 300 mm concrete,

100 mm EPS

U = 0,086 W/(m2K)

THERM 6.3

U = 0,105 W/(m2K) Ψ -0,046 W/(mK) THERM 7.1

Wall construction

U = 0,105 W/(m2K) Ψ -0,014 W/(mK) THERM 7.1

Wall construction

Window

SmartWin fixed U frame 0,57 W/(m2K)

ψ spacer 0,026 W/(mK)

ψ installation 0,010 W/(mK)

SmartWin opening U raam 0,77 W/(m2K)

ψ spacer 0,026 W/(mK)

ψ installation 0,010 W/(mK)

U glas 0,54 W/(m2K)

g-value 0,50

Ψ = 0,014 W/(mK) Ψ = 0,050 W/(mK)

Outside insulation

SmartWin Comparison: not insulated

Window

Ventilation unit

Paul Novus 300 Heat recovery 93%

(PHI def)

Paul Sole Defroster SD-550, 226 m

long 40 mm pipe

airtightness

n50 = 0,31 h-1

Building heat balance in kWh/month

-2500

-1500

-500

500

1500

2500

3500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Hea

t lo

ss a

nd

hea

t g

ain

s in

kW

h/m

on

th

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

Building heat balance in kWh/a

-3073 -311 -367 -1064 -681 -5706 -278 546

-1210

5734

2365

4044

-7000

-6000

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

6000

7000

Ex

teri

or

Wal

l

to A

mbie

nt

Ex

teri

or

Wal

l

to C

onse

rvat

ory

Ex

teri

or

Wal

l

to G

rou

nd

Roo

f to

Am

bie

nt

Flo

or

slab

Win

do

ws

(in

cl. th

erm

al b

rid

ges

)

Ex

teri

or

Do

or

Lin

ear

ther

mal

bri

dges

(exte

rnal

dim

.)

Ven

tila

tio

n a

nd

infi

ltra

tio

n

Uti

lise

d s

ola

r

hea

t gai

n

Uti

lise

d i

nte

rnal

hea

t gai

n

An

nual

net

spac

e h

eat

dem

and

Hea

t lo

sses

an

d g

ain

s in

hea

tin

g p

erio

d i

n k

Wh

/a

PHPP 2007, ISO 13790

Window heat balance in kWh/a

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000 5000 6000 7000

North

East

South

West

Heat loss and gain for the heating period in kWh/a

Heat losses Utilised solar gains Non-utilised solar gains

PHPP 2007, ISO 13790

Solar thermal system, calculated annual production 4900 kWh

2 x 1000 L

Sonnenkraft SK IMK

12 m2 roof integrated solar thermal collectors

for warm water

separate array of solar

thermal collectors 13

m2 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

39/33ºC supply/return temperture

2 x 1000 L

Summer

night ventilation

0

10

00

20

00

30

00

40

00

50

00

60

00

70

00

80

00

90

00

10

000

11

000

12

000

Demand

Production

Energy demand and production (kWh/a)

Net space heating demand

Losses of space heat

distribution (non-utilised)

Net energy demand for

domestic hot water (DHW)

production

Losses of DHW storage and

distribution (non-utilised)

Energy demand covered by

GSHP (vertical ground

source heat pump)

Useful energy production by

solar-thermal system for

space heating and DHW

Space heating + warm water heating balance

in kWh/a Calculated values

Solar thermal Heat pump

DHW DHW losses Space heating

Aim: net zero energy house

90 m2 PV panels SolarWorld Sunmodule Plus SW 196 Vario poly

Calculated annual production of the system 10 120 kWh

Electricity demand and production in kWh/a

0

2000

4000

6000

8000

10000

12000

Demand Production

Ele

ctric

ity k

Wh

/a

Photovoltaic

Domestic appliances,

lighting, sauna

equipment etc.

Technical installations

(ventilators, pumps

etc.)

GSHP (vertical ground

source heat pump)

Calculated values:

Calculated PV electricity production

10 120 kWh/a

Calculated electricity demand

90 m2 SolarWorld Sunmodule Plus SW 196 Vario poly

Calculated production:

10 360 kWh/a

• heat pump

• household

• auxilliary

Balance ≈ 0

0

200

400

600

800

1000

1200

1400

1600

1800

July Aug Sept Okt Nov Dez

Sold to grid

Bought from grid

Measured values in 2013

PV generated grid traffic

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

elec

tric

al e

ner

gy

in

kW

h

Sold to grid Bought from grid

Monitoring

• Window and door position sensors (4) – for night cooling and CO2

• Indoor air temperature and humidity sensors (6) – for indoor climate on all floors and

different room types

• CO2 (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 %

1st floor bedroom

1 month period: Aug 24 to Sept 24 2013

30%

50%

Measured indoor air CO2 concentration

1st floor bedroom

1 month period: Aug 24 to Sept 24 2013

400 ppm

1000 ppm

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).