Influence on transmission losses

Calculation results of the effect of thermal bridges on heat transmission losses in housing with different envelope insulation standards are illustrated in Tables 9.2.3 to 9.2.5 (single family detached house, row house and apartment building). The contribution of thermal bridges to the transmission heat losses are up to 25 per cent. The target for the heat transmission through thermal bridges in Passivhaus constructions is below 4 per cent.

In highly insulated house construction, thermal bridges can have a disproportionately negative influence on the actual energy performance compared to conventional construction. Therefore, it is essential to pay careful attention to classical thermal bridge situations and to conduct an analysis of the solutions using tools mentioned above.

Table 9.2.1 Typical guide values for thermal bridges in building constructions

Building envelope

W-values (W/mK)

Standard house

Low energy house

Passive house

Highest floor/roof/attic

0.20

0.12

0.008

Outside wall/ceiling/floors

0.20

0.10

0.008

Outside wall/balconies

0.30

0.15

0.008

Outside wall/window frame

0.20

0.20

0.040

Outside wall/basement

0.20

0.10

0.050

Table 9.2.2 Guide values for thermal bridges between the window frame and

window glass (ONORM B 8110-1)

Window frame

Rvalues (W/mK)

Double and triple glazing

Double and triple glazing

without coating

with coating sealed units

Wood and plastic frame

0.04

0.06

Metal frame

0.06

0.08

Metal frame with insulation

0.00

0.02

Table 9.2.3 Transmission losses in housing with different envelope insulation standards:

Detached single family house

Table 9.2.3 Transmission losses in housing with different envelope insulation standards:

Detached single family house

Building insulation

Standard

Low energy

Passive house

Passive house

standard

house

house

A

B

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

Upper floor/roof/attic

0.50

0.20

0.15

0.12

0.10

0.05

0.10

0.008

Exterior wall

0.40

0.20

0.20

0.10

0.12

0.08

0.10

0.008

Window

1.80

0.20

1.10

0.10

0.70

0.10

0.70

0.010

Basement/ceiling

0.50

0.30

0.20

0.10

0.10

0.10

0.10

0.050

Thermal conductance

(W/K)

37.6

17.3

14.0

3.1

Total transmission losses

(kWh/m2a)

88.7

37.7

23.4

18.2

Transmission losses

through thermal

bridges (kWh/m2a)

14.7

6.8

5.5

1.2

Qthermal bridges/Qtotal ( per ce

nt)

16.6

18.0

23.5

6.8

Table 9.2.4 Transmission losses in housing with different envelope insulation standards: Row house

Building insulation

Standard

Low energy

Passive house

Passive house

standard

house

house

A

B

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

Upper floor/roof/attic

0.50

0.20

0.15

0.12

0.10

0.05

0.10

0.008

Exterior wall

0.40

0.20

0.20

0.10

0.12

0.08

0.10

0.008

Window

1.80

0.20

1.10

0.10

0.70

0.10

0.70

0.010

Basement/ceiling

0.50

0.30

0.20

0.10

0.10

0.10

0.10

0.050

Thermal conductance

(W/K)

58.6

27.7

22.8

4.6

Total transmission losses

(kWh/m2a)

80.5

40.4

24.1

19.5

Transmission losses

through thermal bridges

(kWh/m2a)

11.4

5.4

4.4

0.9

Qthermal bridges/Qtotal ( per ce

nt)

14.2

13.4

18.4

4.6

Table 9.2.5 Transmission losses in housing with different envelope insulation standards: Apartment building

Building insulation Standard Low energy Passive house Passive house standard house house A B

Table 9.2.5 Transmission losses in housing with different envelope insulation standards: Apartment building

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

W/m2K

W/mK

Upper floor/roof/attic

0.50

0.20

0.15

0.12

0.10

0.05

0.10

0.008

Exterior wall

0.40

0.20

0.20

0.10

0.12

0.08

0.10

0.008

Window

1.80

0.20

1.10

0.10

0.70

0.10

0.70

0.010

Basement/ceiling

0.50

0.30

0.20

0.10

0.10

0.10

0.10

0.050

Thermal conductance

(W/K)

195.6

95.1

83.2

12.2

Total transmission losses

(kWh/m2a)

74.5

36.1

23.2

17.9

Transmission losses

through thermal

bridges (kWh/m2a)

11.8

5.2

5.0

0.74

Qthermal bridges/Qtotal ( per ce

nt)

15.8

15.8

21.6

4.1

Solar Power Sensation V2

Solar Power Sensation V2

This is a product all about solar power. Within this product you will get 24 videos, 5 guides, reviews and much more. This product is great for affiliate marketers who is trying to market products all about alternative energy.

Get My Free Ebook


Post a comment