aluthermo roofreflex - slope roof u-value and condensation ......rsi 0.1000 0.3045 was not taken...

Aluthermo Roofreflex - Slope Roof

U-Value and Condensation Risk Calculations

For

LABC Consult

6th November 2014

Melin Consultants are accredited to provide a range of calculation and testing services. They are members of CIBSE Low Carbon Consultants.

Summary

1. Melin Consultants fully audit all work prior to completion and a robust audit trail exists

to demonstrate accountability.

2. All information within this document is based on evidence provided in the form of

drawings and specifications.

3. CPD (Continual Professional Development) records are kept and technicians are

required to complete a minimum 20 hours per year in training activities.

4. Low Carbon Consultants have the expertise and necessary qualifications to offer

advice in a professional capacity on matters relating to Part L of the Building

Regulations and sustainability within the construction sector.

This document contains the following information:

U-Value Calculation

Project Ref: 3336 Report Date: 6th November 2014 Report author: Kyle Jones Function: Technical Sustainability Consultant Authorised by: Darren Baker Function: Senior Consultant

Melin Consultants Ltd, The Beacon, Dafen Business Park, Llanelli, SA14 8LQ0845 094 1593; [email protected]

Documentation of the component 5. November 2014Thermal transmittance (U-value) according to BS EN ISO 6946Source: own catalogue - 3336 - Aluthermo RoofreflexComponent: Slope Roof 400ccs, PU - 0.13

Calculated with BuildDesk 3.4.5

OUTSIDE

INSIDE

This illustration of inhomogeneous layers is provided only to assist in visualising the arrangement.

On the basis of the given information about the inhomogeneous layers, it is not possible to estimate how and where bearing elements intersect each other. It was assumed that the layers intersect crosswise. The size of the areas was calculated corresponding to their percentage of the whole area.

Assignment: Pitched roof < 70°, with insulation between rafters

Manufacturer Name Thickness[m],

number

Lambda[W/(mK)]

Q R[m²K/W]

Rse 0.10001 BS EN 12524 Slate [2000 kg/m³] 0.0050 2.200 0.00232 Inhomogeneous material

layer consisting of: 0.0300 ø 0.013 2.3077

2a BS EN ISO 6946 Well ventilated air layer 90.00 % 0.000 -2b BS EN 12524 Softwood Timber [500 kg/m³] 10.00 % 0.130 -3 Aluthermo Aluthermo Roofreflex 0.0370 0.037 1.0109

Air gaps Level 1: dU'' = 0.01 W/(m²K)4 Inhomogeneous material


4a Own catalogue Low E cavity 87.02 % 0.074 -4b BS EN 12524 Softwood Timber [500 kg/m³] 12.98 % 0.130 -5 Inhomogeneous material


5a Own catalogue Polyurethane Board 87.02 % 0.022 -Air gaps Level 1: dU'' = 0.01 W/(m²K)

5b BS EN 12524 Softwood Timber [500 kg/m³] 12.98 % 0.130 -6 Own catalogue Polyurethane Board 0.0200 0.022 0.9091

Air gaps Level 1: dU'' = 0.01 W/(m²K)7 BS EN 12524 Gypsum plasterboard 0.0125 0.250 0.0500

Rsi 0.1000

0.3045was not taken into consideration in the calculation

Page 1/8




RT = (RT ' + RT '')/2 = 7.98 m²K/W

Correction to U-value for according to delta U[W/(m²K)]

Air gaps BS EN ISO 6946 Annex D 0.0040.004

U = 1/RT + U = 0.13 W/(m²K)

Q .. The physical values of the building materials has been graded by their level of quality. These 5 levels are the following.. A: Data is entered and validated by the manufacturer or supplier. Data is continuously tested by 3rd party... B: Data is entered and validated by the manufacturer or supplier. Data is certified by 3rd party.. C: Data is entered and validated by the manufacturer or supplier... D: Information is entered by BuildDesk without special agreement with the manufacturer, supplier or others... E: Information is entered by the user of the BuildDesk software without special agreement with the manufacturer, supplier or

others.

U = 0.13 W/(m²K) RT=7.98 m²K/W

Page 2/8




Draft of the component (portion in %):

21.76 6.49 43.51 6.49 21.76

A

B

The inhomogeneous layer consists of two zones (A, B).The portion is given in %.

= 87.02%21.76 + 43.51 + 21.76

consisting of material layers: 3, 4a, 5a, 6, 7

= 12.98%6.49 + 6.49

consisting of material layers: 3, 4b, 5b, 6, 7

Upper limit of the thermal transfer resistance R

UA [W/(m2K)] =( Ri,A ) + Rsi + Rse

1=

10.42 + 0.1 + 0.1

1= 0.09

UB [W/(m2K)] =( Ri,B ) + Rsi + Rse

1=

3.51 + 0.1 + 0.1

1= 0.27

RT ' = A * UA + B * UB 1

= 8.55 m2K/W

Lower limit of the thermal transfer resistance R

Rse [m2K/W] = 0.1

R3 '' [m2K/W] = d 3/ 3= 0.0370 / 0.037 = 1.01

R4 '' [m2K/W] = d 4/( 4a * A + 4b * B) = 0.0200 /( 0.074 * 87.02% + 0.130 * 12.98%) = 0.25

R5 '' [m2K/W] = d 5/( 5a * A + 5b * B) = 0.1800 /( 0.022 * 87.02% + 0.130 * 12.98%) = 5.00

R6 '' [m2K/W] = d 6/ 6= 0.0200 / 0.022 = 0.91

R7 '' [m2K/W] = d 7/ 7= 0.0125 / 0.250 = 0.05

Rsi [m2K/W] = 0.1

RT " = Ri " + Rsi + Rse = 7.41 m²K/W

Page 3/8


Documentation of the component 5. November 2014Calculation according BS EN ISO 13788Source: own catalogue - 3336 - Aluthermo RoofreflexComponent: Slope Roof 400ccs, PU - 0.13


OUTSIDE

INSIDE

The list of material layers shown below may differ from those in the U-value calculation printout. Only material layers which are used in the Condensation Risk Analysis are listed.

This calculation of the Condensation risk analysis according to BS EN ISO 13788:2002 has been performed on a construction containing inhomogeneous layers. This calculation is only valid through the selected section. It is advisable that you should also select the alternative position and recalculate the Condensation Risk Analysis for a more complete assessment of the construction.

The CRA calculation for pitched roofs can be very unreliable and caution should be used when interpreting these results. For further guidance the user is advised to follow the recommendation of BS 5250:202 (currently under review).


Name Thickn.[m]

lambda[W/(mK)]

Q µ[-]

Q sd[m]

R[m²K/W]

Aluthermo Roofreflex 0.0370 0.037 200.00 7.40 1.0109Low E cavity 0.0200 0.074 1.00 0.02 0.2703Polyurethane Board 0.1800 0.022 50.00 9.00 8.1818Polyurethane Board 0.0200 0.022 50.00 1.00 0.9091Gypsum plasterboard 0.0125 0.250 4.00 0.05 0.0500


others.

Page 4/8




Condensation risk analysis - summary of main results Calculation according BS EN ISO 13788

Surface temperature to avoid critical surface moisture:

No danger of mould growth is expected.

Interstitial condensation occurs, but all the condensate is predicted to evaporate during the summer months.

The risk of degradation of building materials and deterioration of thermal

performance as a consequence of the calculated maximum amount of moisture

shall be considered according to regulatory requirements and other guidance in

product standards.

-40

-20

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

Interstitial condensation andevaporation per month gc [g/m²]

Component, condensation range

CRA calculations according to BS EN ISO 13788:2002 are used as a guide in predicting interstitial condensation.

This methodology uses some simplifications of the dynamic processes involved and subsequently does have some

limitations. Further information can be found in Information Paper IP 2/05 'Modelling and controlling interstitial

condensation in buildings'' Feb 2005.

The CRA calculation for pitched roofs can be very unreliable and caution should be used when interpreting these

results. For further guidance the user is advised to follow the recommendation of BS 5250:202 (currently under

review).

Page 5/8




Surface temperature to avoid critical surface humidity Calculation according BS EN ISO 13788

Location: London (Heathrow); Humidity class according BS EN ISO 13788 annex A: Dwellings with high occupancy

1 2 3 4 5 6 7 8 9 10 11 12Month Te

[°C]phi_e

---Ti

[°C]phi_i

---pe

[Pa]delta p

[Pa]pi

[Pa]ps(Tsi)

[Pa]Tsi,min

[°C]fRsi

---Tsi

[°C]Tse[°C]

� January 4.9 0.840 20.0 0.695 727 897 1624 2030 17.7 0.851 19.6 5.0February 4.7 0.820 20.0 0.688 700 909 1609 2011 17.6 0.843 19.6 4.8March 6.9 0.770 20.0 0.661 766 778 1544 1930 16.9 0.767 19.7 6.9April 8.8 0.710 20.0 0.629 804 665 1469 1836 16.2 0.657 19.7 8.8May 12.6 0.690 20.0 0.619 1006 440 1446 1807 15.9 0.448 19.8 12.6June 15.7 0.690 20.0 0.636 1230 255 1486 1857 16.3 0.148 19.9 15.7July 17.9 0.680 20.0 0.650 1394 125 1519 1898 16.7 -0.579 20.0 17.9August 17.6 0.700 20.0 0.664 1408 143 1551 1938 17.0 -0.244 19.9 17.6September 14.9 0.750 20.0 0.673 1270 303 1573 1966 17.2 0.459 19.9 14.9October 11.2 0.810 20.0 0.685 1077 523 1600 2000 17.5 0.717 19.8 11.2November 7.6 0.840 20.0 0.690 876 737 1613 2016 17.6 0.809 19.7 7.6December 5.9 0.860 20.0 0.700 798 838 1636 2045 17.9 0.848 19.7 6.0

The critical month is January with fRsi,max = 0.851 fRsi = 0.977

fRsi > fRsi,max , the component complies.

Nr Explanation

1 External temperature

2 External rel. humidity

3 Internal temperature

4 Internal relative humidity

5 External partial pressure p e = e * psat (Te ); psat (Te ) according formula E.7 and E.8 of BS EN ISO 13788

6 Partial pressure difference. The security factor of 1.10 according to BS EN ISO 13788, ch.4.2.4 is already included.

7 Internal partial pressure p i = i * psat (Ti ); psat (Ti ) according formula E.7 and E.8 of BS EN ISO 13788

8 Minimum saturation pressure on the surface obtained by psat (Tsi ) = p i / si ,

where si = 0.8 ( critical surface humidity )

9 Minimum surface temperature as function of psat (Tsi ) , formula E.9 and E.10 of BS EN ISO 13788

10 Design temperature factor according 3.1.2 of BS EN ISO 13788

11 Internal surface temperature, obtained from Tsi = Ti - Rsi * U * (Ti - Te )

12 External surface temperature, obtained from Tse = Te + Rse * U * (Ti - Te )

Page 6/8




Interstitial condensation - main results Calculation according BS EN ISO 13788

Interstitial condensation occurs but all the condensate is predicted to evaporate during the summer months.

The risk of degradation of building materials and deterioration of thermal performance as a consequence of the calculated maximum amount of moisture shall be considered according requirements and other guidance in product standards.

Climcatic conditions Location: London (Heathrow); Humidity class according BS EN ISO 13788 annex A: Dwellings with high occupancy

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecInternal temperature [°C] Ti 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0Internal rel. humidity [%] phi_i 69.5 68.8 66.1 62.9 61.9 63.6 65.0 66.4 67.3 68.5 69.0 70.0External temperature [°C] Te 4.9 4.7 6.9 8.8 12.6 15.7 17.9 17.6 14.9 11.2 7.6 5.9External rel. humidity [%] phi_e 84.0 82.0 77.0 71.0 69.0 69.0 68.0 70.0 75.0 81.0 84.0 86.0

Monthly moisture content per area gc [g/m²] Accumulated moisture content per area Ma [g/m²]

Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep OctAluthermo Roofreflex / Low Ecavity

gc 7 17 19 16 1 -16 -42 -2 --- --- --- ---Ma 7 23 42 57 59 42 0 --- --- --- --- ---

Page 7/8


Documentation of the component 5. November 2014Heat capacitySource: own catalogue - 3336 - Aluthermo RoofreflexComponent: Slope Roof 400ccs, PU - 0.13


The list of materials shown below may differ from those in the U-value calculation printout. Only material layers which are used in the heat capacity calculation are listed.

Single material layers shown in the U-value calculation printout may be separated to meet the exclusion criteria:

A .. The total thickness of the layers exceed 0.1 m.B .. The mid point in the construction is reached.

For insulation layers the following criteria applies:

C .. An insulating layer is reached (defined as lambda




OUTSIDE

INSIDE





number

Lambda[W/(mK)]

Q R[m²K/W]









5b BS EN 12524 Softwood Timber [500 kg/m³] 12.98 % 0.130 -6 Inhomogeneous material


6a Own catalogue Low E cavity 90.00 % 0.074 -6b BS EN 12524 Softwood Timber [500 kg/m³] 10.00 % 0.130 -7 BS EN 12524 Gypsum plasterboard 0.0125 0.250 0.0500

Rsi 0.1000


Page 1/8




RT = (RT ' + RT '')/2 = 5.69 m²K/W


Air gaps BS EN ISO 6946 Annex D 0.003Air gaps and fixings corrections need not be applied, as their total effect is less than 3% (Annex D BS 6946:1996).

0.000

U = 1/RT + U = 0.18 W/(m²K)


others.

U = 0.18 W/(m²K) RT=5.69 m²K/W

Page 2/8





21.76 6.49 43.51 6.49 21.76

22.50

5.00

45.00

5.00

22.50

A

B

C

D

The intersection of the inhomogeneous layers results in 4Zones (A, B, C, D). Information given in %.

= 78.32%4.89 + 9.79 + 4.89 + 9.79 + 19.58 + 9.79 + 4.89 + 9.79 + 4.89

consisting of material layers: 3, 4a, 5a, 6a, 7

= 11.68%1.46 + 2.92 + 1.46 + 1.46 + 2.92 + 1.46

consisting of material layers: 3, 4b, 5b, 6a, 7

= 8.70%1.09 + 2.18 + 1.09 + 1.09 + 2.18 + 1.09

consisting of material layers: 3, 4a, 5a, 6b, 7

= 1.30%0.32 + 0.32 + 0.32 + 0.32

consisting of material layers: 3, 4b, 5b, 6b, 7



1=

7.11 + 0.1 + 0.1

1= 0.14


1=

2.73 + 0.1 + 0.1

1= 0.34

UC [W/(m2K)] =( Ri,C ) + Rsi + Rse

1=

6.89 + 0.1 + 0.1

1= 0.14

UD [W/(m2K)] =( Ri,D ) + Rsi + Rse

1=

2.51 + 0.1 + 0.1

1= 0.37

RT ' = A * UA + B * UB + C * UC + D * UD 1

= 6.10 m2K/W


Rse [m2K/W] = 0.1

R3 '' [m2K/W] = d 3/ 3= 0.0370 / 0.037 = 1.01

R4 '' [m2K/W] = d 4/( 4a * (A + C) + 4b * (B + D)) = 0.0400 /( 0.074 * 87.02% + 0.130 * 12.98%) = 0.49

R5 '' [m2K/W] = d 5/( 5a * (A + C) + 5b * (B + D)) = 0.1100 /( 0.022 * 87.02% + 0.130 * 12.98%) = 3.05

R6 '' [m2K/W] = d 6/( 6a * (A + B) + 6b * (C + D)) = 0.0380 /( 0.074 * 90.00% + 0.130 * 10.00%) = 0.48

R7 '' [m2K/W] = d 7/ 7= 0.0125 / 0.250 = 0.05

Rsi [m2K/W] = 0.1

RT " = Ri " + Rsi + Rse = 5.28 m²K/W

Page 3/8




OUTSIDE

INSIDE





Name Thickn.[m]

lambda[W/(mK)]

Q µ[-]

Q sd[m]

R[m²K/W]

Aluthermo Roofreflex 0.0370 0.037 200.00 7.40 1.0109Low E cavity 0.0400 0.074 1.00 0.04 0.5405Polyurethane Board 0.1100 0.022 50.00 5.50 5.0000Low E cavity 0.0380 0.074 1.00 0.04 0.5135Gypsum plasterboard 0.0125 0.250 4.00 0.05 0.0500


others.

Page 4/8











product standards.

-60

-30

30










review).

Page 5/8






1 2 3 4 5 6 7 8 9 10 11 12Month Te

[°C]phi_e

---Ti

[°C]phi_i

---pe

[Pa]delta p

[Pa]pi

[Pa]ps(Tsi)

[Pa]Tsi,min

[°C]fRsi

---Tsi

[°C]Tse[°C]




Nr Explanation














Page 6/8











gc 19 35 39 34 13 -13 -51 -78 --- --- --- ---Ma 19 54 93 127 140 128 76 --- --- --- --- ---

Page 7/8




OUTSIDE

INSIDE





number

Lambda[W/(mK)]

Q R[m²K/W]









5b BS EN 12524 Softwood Timber [500 kg/m³] 05.83 % 0.130 -6 Own catalogue Polyurethane Board 0.0200 0.022 0.9091

Air gaps Level 1: dU'' = 0.01 W/(m²K)7 BS EN 12524 Gypsum plasterboard 0.0125 0.250 0.0500

Rsi 0.1000


Page 1/8




RT = (RT ' + RT '')/2 = 8.24 m²K/W


Air gaps BS EN ISO 6946 Annex D 0.0040.004

U = 1/RT + U = 0.13 W/(m²K)


others.

U = 0.13 W/(m²K) RT=8.24 m²K/W

Page 2/8





23.54 2.91 47.09 2.91 23.54

A

B

The inhomogeneous layer consists of two zones (A, B).The portion is given in %.

= 94.17%23.54 + 47.09 + 23.54

consisting of material layers: 3, 4a, 5a, 6, 7

= 5.83%2.92 + 2.92

consisting of material layers: 3, 4b, 5b, 6, 7



1=

9.14 + 0.1 + 0.1

1= 0.11


1=

3.51 + 0.1 + 0.1

1= 0.27

RT ' = A * UA + B * UB 1

= 8.58 m2K/W


Rse [m2K/W] = 0.1

R3 '' [m2K/W] = d 3/ 3= 0.0370 / 0.037 = 1.01

R4 '' [m2K/W] = d 4/( 4a * A + 4b * B) = 0.0600 /( 0.074 * 94.17% + 0.130 * 5.83%) = 0.78

R5 '' [m2K/W] = d 5/( 5a * A + 5b * B) = 0.1400 /( 0.022 * 94.17% + 0.130 * 5.83%) = 4.95

R6 '' [m2K/W] = d 6/ 6= 0.0200 / 0.022 = 0.91

R7 '' [m2K/W] = d 7/ 7= 0.0125 / 0.250 = 0.05

Rsi [m2K/W] = 0.1

RT " = Ri " + Rsi + Rse = 7.89 m²K/W

Page 3/8




OUTSIDE

INSIDE





Name Thickn.[m]

lambda[W/(mK)]

Q µ[-]

Q sd[m]

R[m²K/W]

Aluthermo Roofreflex 0.0370 0.037 200.00 7.40 1.0109Low E cavity 0.0600 0.074 1.00 0.06 0.8108Polyurethane Board 0.1400 0.022 50.00 7.00 6.3636Polyurethane Board 0.0200 0.022 50.00 1.00 0.9091Gypsum plasterboard 0.0125 0.250 4.00 0.05 0.0500


others.

Page 4/8











product standards.

-40

-20

20










review).

Page 5/8






1 2 3 4 5 6 7 8 9 10 11 12Month Te

[°C]phi_e

---Ti

[°C]phi_i

---pe

[Pa]delta p

[Pa]pi

[Pa]ps(Tsi)

[Pa]Tsi,min

[°C]fRsi

---Tsi

[°C]Tse[°C]




Nr Explanation














Page 6/8











gc 11 23 25 22 5 -15 -45 -28 --- --- --- ---Ma 11 34 59 80 86 71 26 --- --- --- --- ---

Page 7/8




OUTSIDE

INSIDE





number

Lambda[W/(mK)]

Q R[m²K/W]









5b BS EN 12524 Softwood Timber [500 kg/m³] 05.83 % 0.130 -6 Inhomogeneous material


6a Own catalogue Low E cavity 90.00 % 0.074 -6b BS EN 12524 Softwood Timber [500 kg/m³] 10.00 % 0.130 -7 BS EN 12524 Gypsum plasterboard 0.0125 0.250 0.0500

Rsi 0.1000


Page 1/8




RT = (RT ' + RT '')/2 = 5.70 m²K/W


Air gaps BS EN ISO 6946 Annex D 0.003Air gaps and fixings corrections need not be applied, as their total effect is less than 3% (Annex D BS 6946:1996).

0.000

U = 1/RT + U = 0.18 W/(m²K)


others.

U = 0.18 W/(m²K) RT=5.70 m²K/W

Page 2/8





23.54 2.91 47.09 2.91 23.54

22.50

5.00

45.00

5.00

22.50

A

B

C

D

The intersection of the inhomogeneous layers results in 4Zones (A, B, C, D). Information given in %.

= 84.75%5.30 + 10.59 + 5.30 + 10.59 + 21.19 + 10.59 + 5.30 + 10.59 + 5.30

consisting of material layers: 3, 4a, 5a, 6a, 7

= 5.25%0.66 + 1.31 + 0.66 + 0.66 + 1.31 + 0.66

consisting of material layers: 3, 4b, 5b, 6a, 7

= 9.42%1.18 + 2.35 + 1.18 + 1.18 + 2.35 + 1.18

consisting of material layers: 3, 4a, 5a, 6b, 7

= 0.58%0.15 + 0.15 + 0.15 + 0.15

consisting of material layers: 3, 4b, 5b, 6b, 7



1=

6.16 + 0.1 + 0.1

1= 0.16


1=

2.73 + 0.1 + 0.1

1= 0.34

UC [W/(m2K)] =( Ri,C ) + Rsi + Rse

1=

5.94 + 0.1 + 0.1

1= 0.16

UD [W/(m2K)] =( Ri,D ) + Rsi + Rse

1=

2.51 + 0.1 + 0.1

1= 0.37

RT ' = A * UA + B * UB + C * UC + D * UD 1

= 5.93 m2K/W


Rse [m2K/W] = 0.1

R3 '' [m2K/W] = d 3/ 3= 0.0370 / 0.037 = 1.01

R4 '' [m2K/W] = d 4/( 4a * (A + C) + 4b * (B + D)) = 0.0700 /( 0.074 * 94.17% + 0.130 * 5.83%) = 0.91

R5 '' [m2K/W] = d 5/( 5a * (A + C) + 5b * (B + D)) = 0.0800 /( 0.022 * 94.17% + 0.130 * 5.83%) = 2.83

R6 '' [m2K/W] = d 6/( 6a * (A + B) + 6b * (C + D)) = 0.0380 /( 0.074 * 90.00% + 0.130 * 10.00%) = 0.48

R7 '' [m2K/W] = d 7/ 7= 0.0125 / 0.250 = 0.05

Rsi [m2K/W] = 0.1

RT " = Ri " + Rsi + Rse = 5.47 m²K/W

Page 3/8




OUTSIDE

INSIDE





Name Thickn.[m]

lambda[W/(mK)]

Q µ[-]

Q sd[m]

R[m²K/W]

Aluthermo Roofreflex 0.0370 0.037 200.00 7.40 1.0109Low E cavity 0.0700 0.074 1.00 0.07 0.9459Polyurethane Board 0.0800 0.022 50.00 4.00 3.6364Low E cavity 0.0380 0.074 1.00 0.04 0.5135Gypsum plasterboard 0.0125 0.250 4.00 0.05 0.0500


others.

Page 4/8











product standards.

-80

-40

40










review).

Page 5/8






1 2 3 4 5 6 7 8 9 10 11 12Month Te

[°C]phi_e

---Ti

[°C]phi_i

---pe

[Pa]delta p

[Pa]pi

[Pa]ps(Tsi)

[Pa]Tsi,min

[°C]fRsi

---Tsi

[°C]Tse[°C]




Nr Explanation














Page 6/8











gc 29 50 55 49 23 -10 -58 -92 -48 --- --- ---Ma 29 79 135 183 206 196 138 46 --- --- --- ---

Page 7/8

aluthermo roofreflex - slope roof u-value and condensation ......rsi 0.1000 0.3045 was not taken...

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