3 light has become lighter - m. cohen

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Light has become lighter

the fascination of light building

Michiel Cohen, architectenbureau cepezed

19-07-2007, Brussels

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1 ASB joist

2 Steel channels3 Rockwool insulation (sealed)

4 Ground car tyres

5 Profiled steel sheet

6 Anhydrite screed

7 Anhydrite tile8 Electrical connection duct9 Ventilation grille

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Section floordeck

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The steel floordeck system integrates the following applications within a total thickness of <400 mm:

•Load bearing capacity

•Stability

•Acoustic insulation (impact and airborne)

•Ceiling

•Ventilation and cable ducts

•Heating

•Fire resistance

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winter ventilation

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Costing

Cost comparison for the steel floordeck.

Standard office space with:

span 7.2 m

live weight 3kN/m2

free room height 2.7 m

acoustic insulation value 0dB

fire resistance ≥ 60 min.

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Hollowprestressedconcrete

Wingfloor Slimdeck Steeldeck

Dead weight 400 358 200 120

Height

Free ceiling height in mm. 2700 2700 2700 2700

Suspended ceiling 50 50 50 0

Installation space 450 0 450 0

Girders 300 15 15 15

Construction height 250 250 270 400

Screed 70 70 70

Total height 3820 3085 3555 3115

Cost

Floor elements 68 75 90 150

Floor covers 17,5

Extra building time 8 8

Extra weight foundation 1 1

Extra steel structure 10 10

Extra surface facade 61 39 2,5

Extra height partitions 8 5 1

Fitting cost

Electrical installation 10 10 10

Heating etc. 11 15 11

Extra installation (height) 15 10

Air ducts 15 15 15

Suspended ceiling 20 20

Plaster ceiling 7

Extra acoustical 17 17 17

Extra cover install duct 35

Total cost 244 210,5 217 153,5

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Frequency 63 125 250 500 1000 2000 4000 I IU,k

Normcurve - 70 66 66 66 70 - 0

TNO

rapport

TNO CPZ - 66.4 67.2 66.6 65.8 62.3 - + 1

TNO- IFD 56.7 66.9 69.6 70 64 52.6 40.5 -2

TU/e

rapport

TU/e- IFD 59.4 69.6 70.7 71 64.9 55.2 44.7 -3

Impact sound insulation steel floordeck

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Frequency - 125 250 500 1000 2000 4000 IIU,k

Normcurve - 34 43 50 53 54 - 0

TNO

rapport

TNO CPZ - 42.5 44.0 51.8 56.7 60.7 - 0

TNO-IFD 22.9 29.0 38.7 50.9 53.7 57.9 61.5 -6

TU/e

rapport

TU/e-IFD 30.7 34.4 43.5 54.0 56.0 59.3 59.0 -1

Airborne sound insulation steel floordeck

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Fire test

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Fire testing results

Duration

of test

Furnace

temperature

Average

temperature

Maximum

0 34,9 0 0

15 716,3 0,93 0,91

30 834,3 6,69 8,26

45 897,2 19,12 23,35

60 943,8 36,39 41,85

62 948,20 38,97 44,52

64 949,77 41,70 47,39

66 954,13 44,66 50,93

68 958,19 47,59 53,92

70 955,66 50,88 58,17

72 958,76 53,89 62,42

74 962,59 57,01 69,08

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Thermal behaviour

Thermal behaviour is to be proven to be equal or better than existing systems.

However the behaviour of lightweight structures is entirely different from traditional ones.

In particular the total energy in a building has to be considered.

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The measures that caused the drop in the demand for heating energy resulted in the change of proportional use

of that energy:

1960 to 1980

Improved insulation and the use of insulating glass

resulted in lower transmission rates but relatively higher

ventilation losses.

1980 to today

More electrical home equipment (heat sources)

combined with a higher air-tightness of the building envelope introduced the problem of cooling.

Component analysis: change in

proportional use of energy

E-in E-outloss of effectiveness

transmission

ventilation

heating

solar energy

internal sources

1960

1980

today

loss of effectiveness

transmission

air leaks& mechanicalventilation

heating

solar energy

internal sources

loss of effectiveness

transm. heating

airl. & mech. vent.

heating

cooling

solar energy

internal sources

transm. cooling

energy flows in residential buildings (except energy for hot water)

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Floor/deck system

Constructive advantages

• Reduced floor-to-floor height

• Prefab

• Possibility to integrate building facility systems

• Low weight

Disadvantage:

Low Thermal Energy Storage (TES)

No possibility for peak-reduction at high thermal loads

Possible result: high indoor temperatures

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Floor/deck system

How can we increase the TES of the floor/deck system, so that we can

use the floor/decksystem as an indoor- climatecontroller?

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Solutions

Add materials with a high heat capacity: e.g.

concrete.

No option: large increase in floor-weight

Add materials with a high latent heat capacity: e.g.

Phase Change Materials (PCM).

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Phase Change Materials

• What is it?

Materials that can store or release a large amount of thermal energy through phase-change:

Solid Liquid.

• How does it work ?

A part of the internal thermal load is applied for phase-change.

Result: Peak load reduction/shifting and/or lower indoor temperatures – lower energy consumption for heating andcooling

melting

congealing

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Potential integration of PCM in floor/deck system

tem

pera

ture

23 degrees Celsius

26 degrees Celsius

one day cyclus

indoor temperatureconventionalfloor/deck system

floor/deck system integrated withPCM

peak-reduction

Results

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Is it finished yet?

NO!

The floor/deck system is also suitable to integrate active indoor-climate systems in order to cope with higher thermal loads.

Benefits:

-Adjustable (individual) climate controlling

-Quick response

Floor/deck system

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Active systems

- energy transfer medium -

Air: mainly convective systems

Water: mainly radiation systems

Chilled ceiling

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Concepts of chilled ceilings in floor/deck system

Horizontal tube-system

Capillary tube system

Perforated ceiling system

Vertical tube system

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A solution

Combinations of passive (PCM) and activesystems:

- Air-cooled PCM (day and/or night-cooling)

- Water-cooled PCM (day and/or night-cooling)

Example of a watercooled PCM in

floor/deck system

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Results

• Integrating PCM results in increasing thermal energy storage (TES) with low increase of the specific weight (approximately 5%).

• Possibility to combine active and passive systems like a PCM withnight-cooling (air- or water-cooled) is possible.

• Suitable solutions are expected to be possible between low and high thermal loads (adaptive) by using passive (PCM) and active systems, and combinations of both.

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Further research

• Verify the simulation results by measuring.

• Which PCM give the best results for latent heat storage in office buildings.

• How can active systems be integrated into the floor/deck.

• Which shape of PCM has the best heat- transfer characteristics.

• In which suitable way active systems can be integrated into the floor/decksystem.

• Savings on energy-consumption are still under investigation.

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Information to be fed to the market is:

Fire resistance performance

This yet has to be finalised in a full scale test though the present values make 90 minutes fire resistance feasible.

Acoustical performancePerformance has been field tested and is sufficient for requested values.Performance can still be optimized but this requires further development.

Thermal behaviour

And naturally Cost

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Markets can be approached through different means.

1. Project oriented.

2. Market oriented.

3. Combined effort.

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1 project

2 market

3 combined

time

pro

jects

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Kickstart steel housing system

careful detailing throughout

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3 light has become lighter - m. cohen

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