Author: Kristin Van Damme
Keywords: poster, template, sjabloon, A3, aanpasbaar

Analysis of thermal bridges
Kaho Sint-Lieven extension building

Rosa T. Monzo Gimeno
Thermal insulation analysis1

1 VAKGROEP IT - KAHO Sint-Lieven, Gebroeders De Smetstraat 1, 9000 Gent, Belgium

INTRODUCTION

Thermal bridges are regions in a building where, because of either the geometry or the materials present, the heat flow from inside to out is higher than in other areas. Besides adding to the heat loss and therefore the energy demand of the building, thermal bridges also cause the temperature of the internal surface to fall, increasing the risk of condensation or mould growth.
The heat loss at thermal bridges is represented by the linear thermal transmittance or Ψ-value in W/(m·K). The sum of the products of the length and Ψ-values of all the thermal bridges can be added to the loss through the plane areas to give the total loss as:
∑A·U + ∑l·Ψ (W/K )
This master tesis calculates the Ψ-value in Kaho Sint-Lieven building E extension with real data provided for trademark products.

A: area m2
U: thermal transmittance (W/m2K)
Ψ: linear thermal transmittance
l: length

Objectives
Calculate thermal bridges with real data of the building, built to be a model of energy performance: the building E extension. The standards used for calculating are ISO 12011, 6946, 6947 and Flemish EPB.
Document and comment the details
Compare results with benchmarks from energy standards like Flemish EPB and Passive House standard.
Building
Materials

D1

C1

A1

B1

C2

A2

B2

C3

C4

A3

C5

Adapting length details

The cut-off planes must be situated the distance of 1m far from the thermal bridge according to ISO 10211

In the window case is not necessary to analize the glass according to Flemish EPB regulation.

CALCULATION
Software used
Flixo 7 was the software used. Every detail, following the instructions in methodology, is drawn in .dxf file and after it is imported in Flixo.
Assigning materials
Using the data sheets collected before and using data base of Flixo, ISO 10456, when it is not possible.
Boundary conditions
Calculating the thermal linear transmittance (Ψ-value)

Type	Temperature	Rsi, Rse
Exterior, normal	0ºC	0,04 m2K/W
Exterior, ventilated	0ºC	0,13 m2K/W
Interior, normal, horizontal	20ºC	0,13 m2K/W
Interior, heat flux, upwards	20ºC	0,10 m2K/W
Interior, heat flux, downwards	20ºC	0,17 m2K/W
AOR (unheated room)	0ºC	0,13 m2K/W

Flixo 7 has several options. It was necessary to check that every option correspons with standards used.

The magnitude of the Ψ-value depends on several values: the quality of the construction, the quality of the dimensions, as well as the U-value which calculates the loss of heat of the undisturbed component. Also, this value depends of the point condidered for the calculation.

where:
Φ: heat flux (W/m)
ΔT: if there are more than 2 boundary condition temperatures.
U1: U-value for the whole construction part 1(W/m2K)
U2: U-value for the whole construction part 2 (W/m2K)
l1: length of the projection of the line segment 1
l2: length of the projection of the line segment 2

METHODOLOGY
Collecting data sheets
*This 𝜆 value has been calculated with U-value given by the trademark (Afinco), 0,93W/(m2·K).
The shutters have been modeled as slightly ventilated air cavity according to ISO 10077-2. Point 6 Treatment of cavities.
The Gaps in technical ceiling are unventilated according to ISO 10077-2. 6.3.3 Unventilated non-rectangular air cavities.
Simplifying the detail
deleting no useful elements and simplifying the geometry according to ISO 12011, point 5.3.2 Conditions for adjusting dimensions to simplify the geometrical model. The most important condition is only materials with thermal conductivity less than 3W/(m·K) can be modified.
This building has a ventilated façade and it will be considered like well-ventilated air layer according to ISO 6946 point 5.3.4 Well-ventilated air layer.

Material	Type		standard
		W/(m·K)	reference
tiles	generic	1,3	ISO 10456
slightly ventilated air cavity	ISO	-	ISO 10077-2
wood fiber boards	trademark	0,05	EN 13986
cellulose	trademark	0,039	ISO 10456
OSB3	trademark	0,13	EN 13986
acoustic panel	trademark	0,063	-
timber 700kg/m3	generic	0,18	ISO 10456
timber 500kg/m3	generic	0,13	ISO 10456
timber window frames	trademark	0,1436*	-
timber flange I-beams	trademark	0,13	EN 12524
fibreboard web I-beams	trademark	0,18	EN 12524
plasterboard	generic	0,21	ISO 10456

Material	Type	𝜆 / s	tandard
	W	/(m·K) / r	eference / p
lasterboard / g	eneric / 0	,21 / I	SO 10456 / c
oncrete with 2%steel / g	eneric / 2	,5 / I	SO 10456 / b
rick / t	rademark / 0	,26 / -	g
ypsum / g	eneric / 0	,43 / I	SO 10456 / c
ompressive strenth / t	rademark / 0	,05 / -	u
nventilated air cavity / I	SO / -	I	SO 10077-2 / g
lasswool / t	rademark / 0	,04 / -	E
PDM / g	eneric / 0	,25 / I	SO 10456 / e
lastomeric foam / g	eneric / 0	,05 / I	SO 10456 / p
anel / I	SO / 0	,035 / I	SO 10077-2 / A
luminium / g	eneric / 1	60 / I	SO 10456 / S
olid brick / g	eneric / 1	,46 / N	BN 62-002

Examples in the Flemish-EPB to considering the point of calculation

Results and comparasion

The standards used to make the comparasion are the Flemish-EPB and the Passive House. The Passive House has only a value of 0,01 W/(m·K) and in the EPB-regulation this values depends on the type of termal bridge, therefore sometimes EPB is more restrective than Passive House standard.

Type of thermal bridge	Limit value
External corners / -wall/wall connection / -other external corners	-0,10 W/(m·K) / 0,00 W/(m·K)
Internal corners	0,15 W/(m·K)
Wall/window and wall/door junction	0,10 W/(m·K)
Foundations	0,05 W/(m·K)
Balconies	0,10 W/(m·K)
Others	0,00 W/(m·K)

Flemish EPB-regulation

Rosa T. Monzo Gimeno
Thermal insulation analysis 1
With Reference1,3
To Company3,4
In Superscript2

1 VAKGROEP IT - KAHO Sint-Lieven, Gebroeders De Smetstraat 1, 9000 Gent, Belgium
2 DISTRINET - Katholieke Universiteit Leuven, De Croylaan 56, 3001 Leuven, Belgium
3 Aqua-ERF, KAHO Sint-Lieven, Hospitaalstraat 23, 9001 Sint-Niklaas, Belgium
4 Opleiding Vastgoed, KAHO Sint-Lieven, Kwalestraat 154, 9320 Aalst, Belgium