Straw bale building Training for European Professionals: Building Physics & Sustainability by Herbert Gruber

HEATprotection MOISTURE protection SOUND protection FIRE protection ROOM CLIMATE BUIDLING PHYSICS SUSTAINABILITY CLIMATE protection

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

CONTENT

U6 TIME

PAGE 5

U6 Learning Outcomes

U6 Session 1 : Introduction Info 1 : Building Physics & Error Prevention U6 Session 2: HEATtransfer Info 2: Heat Insulation

7 8 12

001 -1 2 terms heat transfer, 002-1 4 building physic basics, 003-1 5 minimum required thermal protection, 004-1 6 heat bridge prevention, 005-1 6 heat accumulator, 006-1 8 amplitude attenuation and phase shift, 007-1 8 air and wind tightness

U6 Session 3: HUMIDITYtransport Info 3: Moisture Protection

21 22

U6 Session 4: SOUNDprotection (Acoustics) Info 4: Sound Protection

U6 Session 5: Flammability and FIREresistance Info 5: Fire Protection

43 44

U6 Session 6: Health, Comfort und ROOM CLIMATE Info 6: Heat Bridges and Room Climate

47 48

U6 Session 7: Energy Performance & Programs Info 7: Building standards and Energy Consumption

51 52

U6 Session 8: Environmental Sustainability Info 8: GWP, LCA and Climate Protection

54 55

U6 Session 9: Economical & Social Sustainability Info & Discussion: Sustainability Credits and Imprint

58 59 60

008-22 Terms, 009-24 Moisture Pollution, 010-24 Constructive Wood Protection, 011 25 Constructive Moisture Protection, 01 2-26 Building Physical Properties, 01 3-26 Condensation, 01 4-27 Diffusion-open construction, 01 5-28 Secondary Condensation 01 6-28 Condensate at Window, 01 7-30 Moisture transport via airflow

33 34

01 8-34 Sound insulation terms, 019-36 Building acoustics, 020-38 Minimum requirements sound insulation, 021 -40 single-walled walls, 022-41 impact sound insulation (ceilings)

023-44 Building Classes

024-49 Health, Comfort and Room Climate

025-52 Energy Pass and Energy Efficiency

BUILDING PHYSICS

U6 – BUILDING PHYSICS AND SUSTAINABILITY

LEARNING OUTCOMES

U6 Level 3 (ECVET credit points: 1 5) / Level 4 (10)

Knowledge Trainees know … • the characteristics of the different materials ( λ[Lambda], ρ [Rho], μ [My], CO 2 storage, …). • the forms of heat transfer (conduction, radiation, convection). • the importance and principles of cold and heat protection in winter and summer. • the capacity (advantage) of straw in thermal and humidity storage (living comfort). • about thermal bridges and how to minimize them. • importance of airtightness and windproofness. • the humidity transport (vapour, capillary, convection) and the principles of moisture protection. • the importance of rain protection. • the conditions for mould growth (temperature, moisture, time ofexposure). • the s d value of different materials used for the exterior wall. • the acoustic performance ofstraw constructions. • the principles offire protection with building matter and constructive elements.

Skills Trainees can … • build airtight details and detect air leakages and repair them. • calculate the heat resistance (R-value, U-value) ofconstruction elements with online tools.

Competence

Trainees can … • create awareness ofairtightness and thermal bridges as well as ofhumidity problems. • exchange with other players about fireproof requirements. • detecting faults in building parts and identify the responsible party to inform her.

INTRO

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S1

Session Plan U6-S1 : Introduction Objectives:

Introduction Learning of the importance and development of building physics and its meaning in the realm of straw building

Methods:

Lectures Workshop

Trainer:

Place:

Classroom Workshop

Duration: 1 hour

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Theory

Lectures, charts, presentations ...

Practice

Researches on different topics World cafe to get the message spread and understood

Documents:

Info Sheets: I1 Introduction I2 Heat Protection I3 Fire Protection I4 Sound Protection I5 Moisture Protection I6 Health, Comfort and Room Climate I7 Energy Pass and Programs Powerpoint: Intro Building Physics

Organization:

Prepare workspace for participants with enough places and WiFi. Prepare examples of straw information to find on the internet.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S1 : Introduction

INFO 1

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S1 : Introduction

INFO 1

Transfers in a Wall

.. in the course of the season

ρ λ

RHO n 50 [Pa] PASCAL LAMBDA

HEAT WÄRME

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer Objectives:

Heat transfer and its consequences on building-elements and houses Forms of heat transfer (conduction, radiation, convection) Physical characteristics of the different materials (Lambda, Rho) Thermal bridges and how to avoid them Effects of wind and air leaks on heat transfer

Methods:

Practice

Theory

Lectures Exercises Workshop

Lectures, charts, presentations ...

Working groups with 3â&#x20AC;&#x201C;4 participants working on thermal bridge and air leakage examples Calculate U-values with programs (www.u-wert.com) Explain air tightness measures on selected details Measuring surface temperatures on different matters

Trainer:

Place:

Classroom Workshop

Duration: 4 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Documents:

Info Sheets: I1 Terms HeatTransfer I2 HeatTransfer I3 Physical Material Values I4 Heat Bridges I5 Airtightness Powerpoint: Physics: Heat Protection Video/Bilder: Infrared Pictures Blower DoorTest

Organization:

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

001 Heatprotection: Terms Insulation : Measures to reduce heat losses of components or buildings, e.g. covering with insulation materials Heat transfer coefficient (U = Q / A∆T [W/m 2K]), also U-value. Indicates the amount of heat loss per square meter by a component when the temperature difference between inside and outside is 1 ° Celsius (= 1 Kelvin) Heat flow (Q [W]): The heat flow (Q) is a physical unit for the quantitative description of heat transfer processes. It is defined as the heat energy ∆Q transferred in the time ∆t. It can not be measured directly, but is always based on temperature difference measurement, for example in calorimeters. In addition, it is proportional to the material-dependent thermal conductivity. The heat energy always flows from the higher temperature area to the lower temperature area by itself. Temperature difference ( ∆T [K]) Thermal conductivity λ ( ∆ [W/mK]) indicates which amount of heat flows through a defined area in a given time unit and at a certain temperature difference. Thermal bridges: areas in components that have lower thermal insulation than the other shell of a building and therefore cause heat losses

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

Heat storage masses: Structures of heavy materials, e.g. concrete, stone or clay/earth, have a high storage mass. It ensures that the interior temperature remains stable over the course of the day, sometimes even over several days. Decisive for compensating the temperature fluctuations of a day are the surfaces in the interior, as they take up the heat spikes of the day and return at night, with sinking outside temperatures. Temperature Amplitude Attenuation (TAV=Ae/Ai [-]) of the outer (Ae) to the inner component surface (Ai). It is the usual size in the construction industry in connection with the summer heat protection, which indicates how the temperature fluctuations of the outside air are damped by the component. Ideal is the lowest possible temperature fluctuation on the room side, so that the summer midday heat does not penetrate to the inside. Phase shift ( Ď&#x2020; [h]) indicates how long it takes for a change in the outside surface temperature to become noticeable. This is of particular interest in connection with the summer heat protection: if the value is between 10 and 1 4 hours, the heat can be brought out again in the night.

The Bulk Density ([kg/m3]) of wood materials is between 250 and 1000 kg/m3 (softwood ~ 450, insulating materials ~ 1 5 - 300, steel ~ 8.000) depending on the density of the fiber arrangement and glue proportion. Together with the strength values, this also explains the suitability of wood for lightweight construction. The Specific Heat Storage Capacity (cp [kJ/kgK]) indicates the amount of heat [kJ] required to heat a substance (mass [kg]) (mineral materials ~ 1 , wood materials ~ 1 ,6 - 2,5, steel ~ 0,5, water ~ 4,1 ). To heat the same mass of wood needs about twice the amount of heat required for concrete, four times as for steel, and about half as for water. This results in the warming behavior of wooden components compared to mineral substances. The Heat Storage Number (s [kJ/m3K]) specifies the amount of heat required for heating to a volume. It is proportional to the bulk density and the specific heat capacity. The higher the thermal conductivity and the lower bulk density and the specific heat capacity, the faster the temperature changes spread in a substance. This connection forms the Temperature Conductivity (a [m2/h]) (Solid wood ~ 0.00035, steel concrete ~ 0.0035, steel 0.057), which is e.g. the basis for the calculation of the phase shift. Thus, temperature changes spread in concrete ~ 10 times, in steel ~ 1 60 times as fast as in solid wood. Wood reacts slowly to warming and cooling, so it forms a slowly reacting heat storage mass. The Heat Penetration Coefficient (b [kJ/m2 h0,5 K] od. [Ws0,5/m0,5 K]) indicates how quickly a substance stores heat or removes it from the human body (wood materials ~ 10 - 35, steel concrete ~ 1 50, steel ~ 900, aluminum ~ 1 ,300). Materials with a heat penetration coefficient of up to 20 are superficially heated very quickly because the heat is only slowly directed inward (warming), at 20 - 50 a pleasant (warm) surface results the heat flow to the body is felt as unpleasant. Therefore, wood materials are good for floor and wall coverings as well as seating areas, metallic floor coverings should be separated from heat-dissipating substrates by wood materials or thermal insulation.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

Convection Heat Conduction

Thermal Radiation

002 Heatprotection: Building Physical Basics Heat is a physical quantity and that is a process variable. Heat can be transferred by: Thermal Radiation Heat flow (convection) Heat Conduction Thermal energy is transferred from the higher temperature system to the lower temperature system. According to the building this means: There are only thermal (heat) bridges through which heat flows, but never cold bridges, where cold penetrates. A measure of the heat conduction in a certain substance is the thermal conductivity λ [W / (mK)]. The reciprocal of the absolute thermal conductivity is the thermal resistance R with unit [K / W] (Kelvin per watt):

The heat transfer coefficient (U-value, formerly k-value) is a measure of the heat flow through a single or multi-layer material layer, if there are different temperatures on both sides. It indicates the amount of energy that flows through an area of 1 m² in one second, when the two-sided air temperatures differ by 1 K. Buildings and their users are to be protected against heat loss in winter and overheating in summer. The architectural design combines the requirements for interior design and design requirements in these points.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

003 Minimum required Heatprotection (e.g. Vienna): Basically, a distinction is made in building physics: technical heat protection (prevention of condensation) comfortable heat protection (reasonable room conditions) economical heat protection (heating or cooling)

The minimum required thermal protection is defined in the building codes of individual countries (example: Vienna). (1 ) New buildings with apartments or other common rooms must have structural thermal protection which corresponds to the specified maximum permissible energy index "specific transmission heat loss"; in the case of additions, conversions and structural changes, compliance with para. 6 is sufficient. (2) The specific transmission heat loss W / (m³K) is the calculated heat output requirement in Watt per cubic meter of the heated volume and per Kelvin temperature difference between the outside temperature and the room temperature. (3) The requirement classes take account of the different limitation of the requirements for the heated volume. The heated volume VB in m³ is the sum of the gross volumes of all heated rooms in the building. Heated rooms are all rooms of apartments as well as other common rooms. Sales rooms, restaurants and rooms with similar functions need not be included in the sum of the gross volumes of all heated rooms in the building.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

004 Avoidance of Thermal Bridges:

Due to the influence of structural and geometric thermal bridges, structural thermal protection must not be significantly impaired. Thermal bridges lead to a deterioration in the U-value of the entire construction due to the increased heat transfer. Thermal bridges increase the risk of condensate formation due to the lowering of the surface temperature in the interior of the room. Geometric thermal bridges: The inner heat-absorbing surface is smaller than the heat-emitting outer surface. For example: inside corners of exterior walls, connections of openable components, three-dimensional form changes, etc. Constructive thermal bridges: Penetration or partial penetration of components with higher thermal conductivity in low thermal conductivity components. For example: pillars and insulation, installation of balconies. Convective thermal bridges: Examples: Uninsulated fall formation over wall openings. Insulation layers with joints and cavities, lack of thermal separation of installations.

005 Avoidance of Summer Heat: Thermal Mass Storage In summer and in the transitional periods the following effective (technical) means avoid room overheating by sunlight - sunscreens - room ventilation, especially night ventilation - effective thermal mass of surrounding surfaces and components - orientation of the radiation-transmissive surfaces (for example windows) Saving of heating energy: Under winter conditions, the upper limit of the mass to be stored in non-continuously heated rooms can lead to savings in heating energy and / or shortening of the heating-up times. Increasing the solar heating energy requirement: increasing the amount of thermal mass - based on the solar energy permeable surface "SHB"- in regularily heated buildings with sunny favorable locations and orientations, leads to a significant increase in the solar heating energy contribution and thus to a reduction in heating energy requirements (eg fossil fuels).

The following limit temperatures should not be exceeded in summer: + 27 ° C during the day - + 25 ° C during the night

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S2: Heat Transfer

SESSION PLAN S2

Geometric thermal bridges: The inner heat-absorbing surface is smaller than the heat-emitting outer surface. For example: inside corners of exterior walls, connections of openable components, three-dimensional form changes, etc.

Constructive thermal bridges: Penetration or partial penetration of components with higher thermal conductivity in low thermal conductivity components. For example: pillars and insulation, installation of balconies.

Convective thermal bridges: Examples: Uninsulated fall formation over wall openings. Insulation layers with joints and cavities, lack of thermal separation of installations.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

outside temperature and inside temperature fluctuation

006 Amplitude attenuation and phase shift Amplitude attenuation is the ratio of outside temperature fluctuation to indoor temperature fluctuation. For example, if the outside temperature fluctuation is 30 °C and the inside temperature fluctuation is 3 °C, the value of the amplitude attenuation is 10 (30 °C / 3° C). The phase shift is the time between the occurrence of the highest outside temperature and the occurrence of the highest internal temperature - 1 2 hours in the example above. A goal of the summer heat protection is to delay the passage of temperature through a roof or a wall so that the highest temperature of the day reaches the room side, when it is already so cool outside, that you can counteract the room heating of the components by ventilation. The aim is a phase shift of 10 - 1 2 hours. Part of the heat stored in the component is then also discharged back to the outside. Therefore, the temperature of the room side of the construction doen't have the same temperature as on the outside. The relationship between the maximum occurring temperature difference on the outside and inside is called amplitude attenuation. Depending on the design, use and exposure a minimum amplitude damping of 10 to 1 5 is desired. If amplitude damping and phase shift are low with low thermal storage-effective masses, a "Barackenklima" (barn climate) arises.

007 Heatprotection through: air- and windtightness: For a good building-physical performance of a heatable (wooden) building, it is necessary to keep the air permeability of the building envelope as low as possible. Heat loss through leaks can thus be reduced, structural damage avoided and the comfort for the residents increased. Airtight construction is achieved by placing an air-tight layer on the warm inside and a wind-tight layer on the cold outside of the construction. Usually, the airtightness layer is also used as a vapor barrier or barrier to control the vapor diffusion through the component.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S2

Session Plan U6-S2: Heat Transfer

In pre-industrial times, heat was usually produced by means of wood (example: tiled stove). In the interior of the house was therefore a temperature gradient from the heat source to the outer wall. Although this was sealed as much as possible (moss in block construction, later newspapers as a windproof layer under shingles), an airtight shell could not be achieved. Leakage typically occurs at the following locations on the building envelope: Junctions between walls and other walls or floors Junctions between window frames and walls Electrical equipment Access doors and other wall penetrations Common leakage sites are listed in the Figure and explained below:

1 Junction lower floor / vertical wall 2 Junction window sill / vertical wall 3 Junction window lintel / vertical wall 4 Junction window reveal / vertical wall (horizontal view) 5 Vertical wall (Cross section) 6 Perforation vertical wall 7 Junction top floor / vertical wall 8 Penetration of top floor 9 Junction French window / vertical wall 10 Junction inclined roof / vertical wall 11 Penetration inclined roof 1 2 Junction inclined roof / roof ridge 1 3 Junction inclined roof / window 1 4 Junction rolling blind / vertical wall 1 5 Junction intermediate floor/vertical wall 1 6 Junction exterior door lintel / vertical wall 1 7 Junction exterior door sill / sill 1 8 Penetration lower floor / crawlspace or basement 19 Junction service shaft / access door 20 Junction internal wall/intermediate floor The layers must be seamless (!) over the entire building envelope. Joints must therefore be designed so that they remain permanently airtight. Heat loss through a joint: a 1 mm wide and 1 m long joint leads to a deterioration of the insulation value by 4.8 times. 800 g of moisture per day and square meter can get through this gap into the construction: With a dense vapor barrier only 0.5 g will penetrade the construction. General conditions: Indoor temperature: +20 ° C, Outdoor temperature: -10 ° C Pressure difference: 20 Pa = wind force 2-3 Measured values without joint: U-value = 0.3 W/m²K, with 1 mm joint: U-value = 1.44 W/m²K

With a blower door test and thermography the airtightness can be checked.

µ MÜ φ REL. T TAU w kg/(m²h ) 0,5

HUMIDITY FEUCHTE

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S3

Session Plan U6-S3: HumidityTransfer Objectives:

Humidity transfer (capillary, convective, liquid) and methods to prevent problems caused by excess humidity Influence of wind- and airtightness on humidity transfer Influence of physical characteristics and their succession of materials (Lambda, Rho, My, w, w24…) The conditions for mould growth (temperature, moisture, time of exposition) Humidity input by driving rain / driving snow on surfaces (w1 , w24) Flooding inside (leakages) or outside (surface water on slopes at excessive rainfalls or rivers and lakes overflowing) Input of humidity by building materials as green wood, pavements, plasters, concrete basement,... Input of water on plaster/render or pavements and walls per m² which has to be dried out during building process W1 , W24 as to bad storage conditions straw might drop into water on ground (better sort that bales out)

Methods:

Practice

Theory

Lectures Exercises Workshop Group work

Trainer:

Place:

Classroom Workshop

Duration:

3–4 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Documents:

Info Sheets: I1 HumidityTransfer Terms I2 Moisture protection constructive I3 CondensateI I4 Building diffusion-open Powerpoint: Moisture protection

Lectures, charts, presentations ...

Explain protection measures of building site with straw from storage to rising walls until rendering is finished and dried. Measuring humidity in straw bales with different tools Know about drying out (desiccating) time of different matters for plastering on straw per cm layer in average summer climate

Organization:

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

008 Moistureprotection: Terms Absolute humidity Φ = m/V [kg/m3] φ The atmospheric air always contains certain amount of water vapour. It is defined as amount of water in kg per 1 m3. The maximum possible mass of water which contains air depends on temperature o fair. The state with maximum content of water is called saturated state. Relative humidity φ [%] Absolute humidity does not inform us about how far it is from saturated state. That is why we use m max which is maximum mass of water in air for given temperature, compared to the actual amount of water in air in given temperature. The percentage represents the amount of saturation. Specific humidity / Water vapor content (g/kg, kg/kg) (Formula: s, q or x) indicates the mass of water that is in a certain mass of humid air. The numerical value range is 0 ≤ s ≤ 1 , where s = 0 for dry air and s = 1 for air-free steam or liquid water. Condensation is the transition of a substance from the gaseous to the liquid state. The product of a condensation is called condensate. The values for pressure and temperature prevailing during the condensation characterize the condensation point (dew point). During condensation, heat energy is released from the condensate to the environment. This heat of condensation has the same value as the heat of vaporization.

INFO S3

U6 – BUILDING PHYSICS AND SUSTAINABILITY

INFO S3

Session Plan U6-S3: HumidityTransfer

Dew-point temperature The usual temperature of air is too high to admit condensation of water vapour. If the condensation is to appear, the temperature must decrease to critical one. Dew point temperatures at a given temperature and relative humidity are shown in tables.

The Glaser procedure (also known as Glaser diagram ) is a process of building physics, with which it is determined whether and where in a building construction condensate accumulates. The Glaser procedure is named after its inventor Helmut Glaser. It was developed at a time when computer-aided analysis was not possible to the extent that is customary today and was therefore designed as a tabular-graphic method that delivers results quickly and with simple arithmetic operations. Vapor diffusion resistance (factor) The so-called μ value is a material constant and defines how often the diffusion conductivity is smaller than the diffusion resistance of air of the same thickness. In simple terms, the μ value of an air layer is 1. Water vapor diffusion equivalent Air layer thickness (sd, Sd value) is a building physics measure for the water vapor diffusion resistance of a component or a component layer and thus defines its property as a vapor barrier. In contrast to the water vapor diffusion resistance, this also takes into account the thickness of the component. (Sd = μ x thickness in m) Water absorption coefficien t (short w value) indicates how much water a substance absorbs within a certain time. A fabric with the base A is immersed in water. The substance is weighed at certain intervals and you get so each of the mass of absorbed water m as a function of time t. Saturation vapor pressure (Pa, hPa, kPa, bar) (also equilibrium vapor pressure) of a substance is the pressure at which the gaseous state of matter is in equilibrium with the liquid or solid state of matter. The saturation vapor pressure is dependent on the temperature.

The saturation vapor pressure curve (saturation vapor pressure line, vapor pressure curve, vapor pressure line) describes the saturation vapor pressure as a function of the temperature. It corresponds to the phase boundary line of the gaseous phase in the phase diagram. Dehumidification Dehumidifiers are often used to dry the building moisture in new buildings, to dry the walls and wet rooms where high levels of water vapor are generated (swimming pools). These condense the water vapor from aspirated rooms and air, which is leaving the device can then absorb moisture again. Water nipples (also known as drip edges or drip strips) are edges on the underside of projecting components - for example window sills, balconies or masonry tops - which improve the drainage and drainage of (rain) water and thus avoid the underside moisture penetration of components and dirt flags through running water from the facade.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

009 Protection against the following humidity loads must be given > Condensation > Rising moisture > Built-in moisture > wood material damaging influences (for example climate change) > Precipitation > Splash water > Capillary water

010 Constructive and structural Wood protection

Wood and wood-based materials as well as (organic) insulating materials such as bales of straw used in construction must be protected against prolonged exposure to moisture. A sustained relative humidity of more than 20% in combination with heat can lead to fungal infestation as well as deformations as a result of swelling and thus to considerable building damage. The following wood protection measures are used as protection against persistent moisture: constructive and chemical wood protection. Both work preventively. The chemical wood preservation can never replace the constructive wood protection, at most supplement it.

INFO S3

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

INFO S3

011 Constructive Wood- and humidity protection Structural wood/moisture protection includes all structural measures that serve to protect the built-in material against harmful and excessive water absorption as well as high and long-lasting moisture. They prevent the infestation or spreading of (wood) harmful fungi and insects. Already in the planning phase it is important to design the construction in such a way as to avoid the penetration of water into construction joints or the water remaining on the surface of the wood. This can e.g. be achieved by generous canopies, metal covers, bevels and spacers. Earth contacts should be avoided. Rising moisture may be prevented by moisture breaks like with bitumen paper. Attention should be paid to the avoidance of condensation in wall and ceiling structures. Recommended is also the ventilation of the outer cladding. For structural moisture protection measures, it is important to observe the moisture content of the material at the time of installation and to comply with the relevant guidelines. The expected ambient climate also plays a role, because in the wood/straw the socalled compensatory moisture sets in at the installation site in the course of time in accordance with the prevailing humidity. That means a certain humidity corresponds after some time with a certain moisture content. The aim of the moisture protection of the timber construction is to largely avoid cracks and fissures, which can be caused by shrinkage of the wood in case of excessive dehydration. Cracks and joints provide penetration for water and insects and are ideal places for storing their eggs. However, shrinkage cracks can not be avoided with larger cross sections. But they represent no shortage in terms of wood quality. In the case of constructively well-protected components, you should consider giving up entirely on chemical protective measures. A possibly occurring in a few decades, disposal of the wood will therefore be without problems. Especially with easily replaceable parts, such as cladding, this is ecological and economical. The standard for structural wood protection measures in building construction (DIN 68 800-2) shows exemplary wooden structures. Especially vertically installed wood can reach a very long life time even if left untreated, if it is considered that: it is situated completely outside of the foundation/basement area as well as above the splash water area of other horizontal surfaces such as window sills, canopies or balconies and their rain-affected areas are not shaded or covered by vegetation or other elements, so they are usually dried quickly by the sun and wind. In particular, wood joints and other close contact points are to be avoided, in which the rainwater enters and is retained by capillary forces.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

01 2 Physical Properties of various Materials

01 3 Moistureprotection: Condensation Water vapor condenses when the relative humidity exceeds 100% . This can happen in or on the surface of components that have spaces with different climatic conditions from each other. External components are the most exposed ones due to the different climates between inside and outside. In winter the warm air in the living room contains more moisture than the cold outside air. The water vapor therefore flows constantly from the inside through the construction to the outside. It cools down and condenses. Condensation can be prevented or reduced when a vapor-breaking component layer (mounting plate, e.g., OSB) is placed on the warm side of the structure. This reduces the amount of vapor entering the construction. These vapor barriers simultaneously take over the task of the air seal. Clay plaster with airtight connection has a similar effect due to its hygroscopic (water absorbing) properties. A small amount of condensate in the component is often unavoidable and leads only under certain conditions to structural damage. Condensation is harmful to the construction if:

> the accumulated water can not be stored > the water soaks a component layer so that its thermal resistance significantly drops by more than 10% > the building materials are damaged through the condensate, e.g. by fungal attack, corrosion, frost or similar > the occurring condensation water can not dry out in the following drying period and the moisture balance of the construction thereby steadily increases

INFO S3

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

INFO S3

Session Plan U6-S3: HumidityTransfer

The Austrian standard Ă&#x2013;NORM B 8110-2 defines condensate protection as follows: Under condensation protection in building construction all building measures, that secure a temperature on the inside surface of the outside components, must be understood, so that a) no water vapor condensation takes place and b) mold formation is hindered by hindering harmful water vapor condensation inside the outside components.

Reminder:Through a 1mm wide and 1m long fugue, up to 800 g ofmoisture can get into the construction per day. (see p. 19)

01 4 Moistureprotection: Diffusion-open Building ... this means that the vapor pressure resistance of the individual component layers from the warm inside decreases towards the cold outside and should generally be as low as possible. As a result, a high desiccation capacity for removal of (construction) moisture is given. The necessary difference of the vapor pressure resistance from the innermost layer to the outermost layer depends, among other things, on the level of relative humidity in the interior, the use of controlled ventilation in the living space and the moisture absorption capacity of the insulating materials used. For the use of vapor-retarding materials, a ratio of the innermost to the outermost component layer of approximately 1 : 5 to 1 :10 is recommended. For diffusion-open materials, in particular for the use of clay on the inside, it is also possible to calculate with a diffusion ratio close to 1 : 1. In summer, due to the changed climatic conditions, a vapor pressure gradient arises going from outside to inside (but it usually does not condensate). Steam flows through the components into the building. Using a vapor barrier on the inside with a high sd value will trap the moisture in the component. As a result, even in winter condensate can not diffuse out well. For this reason building biologists recommend not using vapor barriers (except where required by law: for example, as a seal to the foundation). Diffusion is a very slow process and involves only about 4% of the room air humidity. The remainder is usually vented away, stored in materials (e.g., plaster surfaces, furnishings, textiles, ...). The moisture entry by driving rain, e.g. is many times higher. However, diffusion must not be confused with leaks! If a house is leaking, a lot of room moisture is introduced into the structure and it can lead to moisture problems like mold formation. In addition, leaking houses always have a higher energy consumption because the insulation is only effective when the air is in the insulation. For these reasons, it is important to make the inside of the wall airtight on all connections (gluing, plastering without cracks, planking, ...) and also not to injure them later (for example, when installing sockets or ceiling spots).

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

01 5 SecundaryCondensation in ventilated roofs Here, the water vapor present in the outside air is reflected in the interior of the construction as a surface condensate. It is not dependant on the diffusion properties of the construction, but rather on the thermal processes in the ventilated structures and the temperatures at the interfaces of the ventilation space. It is recommended, not to leave straw exposed under noninsulated metal roofs.

01 6 Moistureprotection Condensate on Windows

Condensate is generated from the surrounding room climate, and this room climate has changed significantly with all the measures to reduce the heat demand. Two factors are decisive for condensation: the room air humidity and the surface temperature. Moisture comes into the building during construction and renovation and later more or less continuously during use. Sometimes moisture from the outside also penetrates when the air outside is more humid than inside, which can be the case particularly in the damp warmer season. All the moisture which comes in the construction must also be exhausted. Preventing unnecessary moisture is therefore contributing to the reduction of the risk of condensation. If too much moisture is introduced into the building and is not sufficiently ventilated, this

INFO S3

U6 – BUILDING PHYSICS AND SUSTAINABILITY

INFO S3

Session Plan U6-S3: HumidityTransfer

moisture is stored in the building by later added materials, furniture and textiles, which leads to a rapid supply of moisture from these "stores" after the impingement. This results in a high moisture level in the room and an increased risk of condensation. In addition to the moisture level, the temperature actually present on the surface is also important. This again depends on how much heat actually reaches the window and how much heat transfer the window construction and the window connection have. The concentration of condensation on windows, in contrast to the past, as condensation occurred in particular at the lower insulating glass edge and often together with mold formation in the lower region of the slurry, increasingly also shifted into the functional fold and into the joints. How does this happen?

Due to increased thermal insulation, reduced air permeability and the associated reduction of the heating load, but also by the change in the conditions of use and the site and / or external climatic conditions (use of damp valley areas, damp pastures, shaded areas, sloped windy areas for construction), which adversely affect the boundary conditions for the function of the building envelope in terms of condensation. The increased heat insulation results in lower temperatures for our heaters, instead of 60 to 70 ° C flow temperature the surface temperatures of our heating surfaces are often only around 30 ° C. The heat, which was formerly transported into the rooms through strong convection, is thus only released to a much lesser extent, above all, in the form of radiant heat. Areas which are not directly exposed to direct radiation exchange with the heating system are hardly heated. The consequence is a drastic change in convection in the room: while with a low heat insulation, a convection roller, rising from the convector on the outer wall upwards, the ceiling heats up and reaches the floor via the rear inner wall of the room this procedure changes completely, when Facades are insulated well and the surface of the heaters are lower: the glass surface acts as a heat exchanger, the air cools down on the glass surface, the heavier, cooler air falls to the ground. This reduces the temperature especially in the lower regions. If you sit there, a feeling of drafts can be the result, especially with higher windows. The higher the glass area, the more pronounced is this effect, but with higher U-values of the glazing, it decreases again. With increasing heat insulation of the outside wall and decreasing heating capacity, a separate climate zone forms at the window. Deep loops worsen the situation, since there is little heat, but room air humidity stays the same. In addition, multi-storey open constructions lead to increased thermal buoyancy and together with the dense outer sheath lead to higher internal pressures. Together with the wind there is a continuous transport of damp warmer air through the window joints, especially on the upper floors and on the windward side. Condensate in the fold is the consequence; ice formation can occur even if the weather is appropriate due to the fact that the thermally optimized window profiles are cooler in the outer regions.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

017 Moisturetransfer via airstream A particularly high risk of humidification is caused by air flows through leaks in the building envelope. As early as 1989, a laboratory study carried out by the Fraunhofer Institute for Building Physics (ibp) in Stuttgart showed that joints in room-side moisture barriers produce much higher moisture risks than pure moisture diffusion. Certain flow mechanisms are responsible for these moisture damage. Since these residual leakages are unavoidable, they must be tolerated by a fault tolerant construction.

Driving forces and flow direction The diagnosis of moisture damage caused by air leaks in the building envelope requires a detailed knowledge of the driving forces and flow patterns. Not every hole in the building envelope carries the same risk. Particularly when the airflow is directed from the room to the outside in winter, there is the possibility of condensation of water vapor in the construction. The thermal lift is the most critical flow drive. The greater the temperature difference between indoor and outdoor, the stronger the airflow and the greater the risk of condensation. Therefore, in the upper part of the building, typically in the attic, the most significant humidification potentials exist. Leaks in the area of the largest negative pressure (eg in the case of thresholds at entry and terrace doors or the pedestal point) are usually responsible for unpleasantly airflows and the formation of a "cold air lake" in the floor area of the ground floor. However, as a matter of humidification, this is to be assessed as uncritical, since the penetrating outside air always warms up on its way into the interior of the room and thus assumes a lower relative humidity. Since the equilibrium moisture content of all hygroscopic materials follows the relative

INFO S3

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S3: HumidityTransfer

INFO S3

humidity in their surroundings, no unacceptable material moisture can develop on this flow path. Particularly in the case of buildings with wooden beam ceilings, large air leaks are frequently found in the area of the ceiling cavities (eg in timber framework constructions or skeleton structures with many beam penetrations). Whether these leakages represent a moisture risk is also dependent on the leakage distribution. Depending on the position of the relevant ceiling in the building section and depending on the distribution of the leaks via the building envelope, a flow through from the inside to the outside or vice versa can occur. Conclusion: steam convection = risk • Convection usually results in far more moisture transport than diffusion. • Diffusion is large and evenly distributed. Convection forms locally concentrated moisture nests. • Diffusion accumulation water can be completely prevented or limited to a harmless degree. There is no "diffusion barrier" for the convection. As soon as air flows below the (room air-related!) Dew point temperature, condensation takes place. • There is a dehumidifying counter-process in the evaporation period for each moisture load caused by diffusion during the dew period. Convective condensation in the winter does not have a corresponding drying "backflow" in the summer half year. Dehumidification is only possible via diffusion and evaporation. How many reserves does a fault tolerant construction require? Convective moisture risks can best be avoided by careful planning and execution of the air tightness level. In the past twenty years, good conditions have been created for standardizing through publications and the development of innovative products from the producers of tarps and adhesives. But there remains a residual risk. Errors always happen, and to a tolerable extent they must be coped with by the planned design. The new German wood protection standard (DIN 68800-2: 201 2) requires an annual drying reserve of 250 g/m2 for the dew proofing by means of Glaser-calculations to dry the moisture loads from steam convection. By means of hygrothermal simulation methods, the influence of convective humidification can be planned according to the building density. On the basis of such simulations, validated by accompanying outdoor examinations on test buildings, also recommendations of Holzforschung Austria were developed into flat roofs in timber construction.

© 2017, proHolz Austria, Arbeitsgemeinschaft der österreichischen Holzwirtschaft, Text: Robert Borsch-Laaks Remark: The greater the wall thicknesses and the water absorption capacities of individual materials, the more the convection and diffusion moisture in the components is distributed. In addition, especially in straw bale construction with moisture-permeable materials such as loam, straw and lime and by the hygroscopic properties of clay on the inside of the wall (acts as a vapor barrier) moisture levels can dry out relatively well and quickly. Measurements of the GrAT with the "mobile test laboratory" directly after plastering (80 - 90% relative humidity in the wall) and after 1 week (equilibrium moisture content of 1 3-1 4%) have also confirmed this. Nevertheless, wherever possible air leaks should be avoided on the inside of the room!

Rw (dB)DECIBEL f (Hz)HERTZ p (Pa)PASCAL D nT,w LnT,w

SOUND SCHALL

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S4

Session Plan U6-S4: Acoustics Objectives:

Acoustic phenomena and principles of sound transmission by air, liquids and solid matter Difference between different phenomena (airborne noise and impact sound pressure) Protection against airborne noise and weighted normalized impact sound pressure level Effects of mass and decoupling of layers of building parts on noise reduction Examples for building parts and their sound reducing capacity

Methods:

Lectures Exercises Workshop

Trainer:

Place:

Classroom Workshop

Duration:

2–3 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Documents:

Practice

Theory

Lectures, charts, presentations ...

Working groups with 3–4 participants working on detail examples Finding sound reducing values for different building parts. Examine building regulations for acoustic measures. Compare measured straw building components with regulations valid in your country. Calculate the specific weight of building part (wall, roof) per m² to give indicator to good or bad acoustic performance. Calculating the density of straw bales

Info Sheets: I1 Sound-Protection-Basics Text Sheets: X1 Building Law Vienna and EU-national laws X2 Sound-Insulation Tests Powerpoint: Sound Protection

Organization:

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

INFO S4

Session Plan U6-S4: Acoustics

018 Sound Protection: Terms and Concepts Sound (Schall): is caused by mechanical vibrations in solid, liquid or gaseous bodies. It propagates from the source of the sound spherically, by vibrating the surrounding air or other media. The sound waves propagate in a straight line, but are impacted by reflection, absorption, diffraction or refraction when they encounter an obstacle. Airborne sound : Sound that spreads in the air. Structure-borne sound : Sound, which is caused by the excitation of solid bodies and is partially radiated again as airborne sound. Impact Sound: Noise generated by structure-borne sound excitation in an adjacent room caused by excitation of ceilings, e.g. jumping. For the excitation for measuring special, standardized devices are used (ISO tapping machine, rubber ball). Frequency f (Hz): Number of ocurrences of a complete oscillation per second. Vibrations can be perceived by the young human ear as sound when they have a frequency of about 20 to about 20,000 Hz and are above the hearing threshold. Decibel (dB): The decibel is a logarithmic scale. The sound intensity is recorded from the relative value 1 (hearing threshold) to the value 10 trillion (pain threshold) in figures from 0 to 1 30 dB(A). 10dB correspond to a doubling of the noise; hearing damage can occur from 85 dB(A). In combination with other stress factors, health damage is possible at much lower noise levels.

A-Rating : The human ear perceives deep and very high tones less loud than midrange tones. This is taken into account insofar that when measuring, the frequencies

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

INFO S4

contained in a sound are weighted differently in accordance with the "A-curve". If an A-rating is used, the measurements are given in dB (A). The A-rating is in the range of lower sound pressure levels (approx. 40dB), which are relevant for our everyday listening. For higher sound pressure levels the evaluation curves B (approx. 70dB) and C (approx. 100dB) apply. Resonance is the co-vibration of a vibrating material on the occurrence of sound waves. Resonating bodies (soundboxes) can be used e.g. for absorbing airborne sound (e.g., plate resonator in acoustics) or amplification of body sound (e.g., vibrating string). Resonance Phenomenon : In physics, resonance refers to the compliance of the frequency of an excitation with the natural frequency of a system. In soundproofing systems this leads to a significantly reduced sound insulation. A sound-insulating component should therefore be dimensioned so that resonance frequencies are as far outside the building acoustic frequency range as possible. Rated Sound Reduction Index Rw (dB): This depends on the frequency and is evaluated in the building construction for the frequency range between 100 and 31 50 Hz and measured in the extended frequency range between 50 to 5000 Hz (third octave band center frequencies). As a single value, the Sound Reduction Index is calculated by comparing the measured curve of the component with the reference curve. The value of the reference curve, which is shifted up to the permissible sum of the 32dB insulation values at 500 Hz, is the value of the Rated Sound Reduction Index. Sound Pressure p (Pa) The pressure fluctuations produced by vibrations, through which the eardrum is excited to resonate. A-weighted sound (pressure) level : Sound level which, taking into account the eva-luation curve A, takes into account the frequency-dependent sensitivity of the human ear. The range of the hearing threshold to the pain threshold ranges from 1 dB to about 1 20dB. Rated Standard-Sound Level Difference D nT,w (dB) is dependent on the frequency and is measured for the frequency range 100 to 31 50 Hz or 50 to 5000 Hz. The rated standard sound level difference is calculated as a singular value by comparing the measured curve of the component with the reference curve. The value of the reference curve, which is shifted to the measured curve to the permitted average value of 2dB at 500Hz, indicates the rated standard sound level difference. Impact Sound Insulation describes the ratio of the excitation to the emission of sound by walking, etc. on a ceiling. For the measurement, a standard hammering system is used in the transmitter space and the air sound level in the reception area is determined. Rated Standard-Impact Sound Level L’nT,w (dB) is a single figure for the evaluation of the impact sound protection in a building. If, like the rated sound insulation measure and the reated sound level, the frequency-dependent sensitivity of the hearing process is linked by means of a reference curve. Impact Sound Reduction ∆L (dB) of a floor or a suspended ceiling is the difference between the standard impact sound level of the unfinished floor and that of the unfinished floor with floor structure or suspended ceiling.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

019 Sound Protection: Building Acoustics The materials of the wooden / straw construction are lighter than those of the solid construction. High sound insulation can not be produced with single-shell, plateshaped timber construction (straw construction) elements in an acceptable component thickness due to lack of basis weight. The solution lies in the use of double to multi-shel l constructions with bend-soft shells. Regardless, it sometimes makes sense to use a heavy mass complementary. For the building acoustics approach, it is expedient to take into account the acoustic laws and the general sound insulation requirements. In the case of airborne and impact sound insulation , the "customary noises" or standard normal noises form the basis for the required minimum soundproofing dimensions which must be complied with in adjacent functional units or rooms. In addition, there is the standard "increased sound insulation". Even within a functional unit one can define "rooms to be protected" to meet these increased requirements. Typical of this is e.g. the bedroom of a family house.

Relevant frequency range For general sound insulation, the " building acoustically relevant frequency range" is currently decisive for the standard assessment. This range of pitch ranges from 100 Hz to 31 50 Hz and, together with the sound insulation values, is a compromise between reasonable subjective annoyance and current feasibility, both technically and cost-effectively. The ISO 71 7 (Ă&#x2013;NORM EN ISO 71 7) also provides spectrum adaptation values C for measurement and detection calculation in addition to the weighted sound attenuation measurements: They are clearly added as positive or negative correction

INFO S4

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

INFO S4

values to the airborne sound or impact sound insulation measure if the frequency range covered has been extended or if sound other than customary noise has to be soundproofed. Basic principles of acoustics With some knowledge of the following fundamental principles of acoustics, the various manifestations of building acoustics and constructs can be better understood and unnecessary errors avoided. Berger’s Law of Mass for Sound Insulation It is substantial for heavy solid walls and solid ceilings from a surface mass m 'of approx. 100 kg/m². According to this law, the air-sound insulation measure increases as the surface mass, ie the thickness of the components, increases. This results in the solid construction of the known thickness dimensioning of separating components for usual standard requirements, e.g. the required surface area m'= 400kg/m² (approx. 20 cm concrete wall thickness) for apartment walls. The lower density of wood construction materials would make a wall thickness of about 2 to 3 times the thickness necessary for walls and ceilings. Consequently, in wood construction, the required sound-absorbing dimensions must largely be produced using a different acoustic law, namely the resonance phenomenon. Resonance Phenomenon and Coincidence Effect This phenomenon pervades the entire building and room acoustics with its law. It is based on the fact that each spring-loaded mass has a system resonance with a defined natural frequency. Partly well-known examples of such oscillatory systems are e.g. elevator machine sets resting on elastic rubber elements. Such "spring / mass systems" behave like a weight attached to a coil spring. If you then let the weight vibrate vertically, it does so with the typical natural frequency, the resonant frequency per second in Hertz. At this natural frequency and in its vicinity, large, excessive oscillation widths are produced with only a slight impulse. It comes to a " resonance amplification " of vibrations. However, if the oscillation number of the excitation force, e.g. the engine speed per second, is well above the natural frequency, then the swinging is suppressed intensively, the vibrations will be transmitted in a much more reduced way to the supporting surface. The vibration suppression is already very pronounced when the excitation frequency is three times greater than the natural frequency.

Particularly problematic is the structure-borne sound energy, which - once penetrated into the timber structure - can experience significant reinforcements by resonance enhancements on various structural parts. Their propagation must be prevented already at the vibration source. Plate-shaped separating components are also excited by the impact of airborne sound to bending vibrations, which propagate in this component as water surface waves and on the other side of the component lead to a sound radiation. Now, if the airborne sound wave and the bending wave caused thereby run parallel on a wall at the same speed, then coincidence arises at a certain frequency, the coincidence limit frequency fG . About above the triple fG again the Berger mass law is decisive. It is important to keep this strong reduction in sound insulation outside the building acoustics relevant frequency range. This means that the coincidence limit frequency fG should be 31 50 Hz or higher or 100 Hz or less.

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

020 Minimum requirements for Soundinsulation in the walls § 99. External walls (Building Code Vienna)

(3) The non-transparent parts of the exterior walls of dwellings and living rooms shall have a rated sound reduction index Rw of at least 47 dB for each room and at least 38 dB for the transparent parts. In any case, for exterior walls of dwellings and lounges at each room must have a resulting weighted sound insulation measure R res,w of at least 43 dB. § 100. Interior walls (Building Code Vienna)

All partitions must have sufficient sound insulation. In the case of partitions between flats and operating units, sound insulation is considered to be ensured if the weighted sound reduction level R w is at least 65 dB, for other partitions, if the weighted sound reduction level R w is at least 58 dB. Apartment entrance doors must have a rated sound reduction index R w of at least 33 dB.

INFO S4

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

INFO S4

Session Plan U6-S4: Acoustics

Soundproofing tests (e.g., by FASBA, see above) have yielded sound insulation values between 42 and 44 dB for plastered single-shell straw bale walls.

Measurements/tests at theTechnical University of Ostrava (CZ), each with 25 mm clay plaster on both sides, gave a Rw = 54 dB, while the bare straw bale wall had an Rw = 28 dB. This indicates that sound insulation in straw bale building is essentially achieved by the (heavy) plaster surfaces. The minimum sound requirements demanded by the state building regulations can only be fulfilled in single-family homes, for multi-family or terraced houses, (see left), straw bale walls plastered on both sides are not enough; they must be constructed with multiple layers. Two examples of multi-layered walls were tested atTU Ostrava: on one side, the straw bale walls were plastered with 25 mm clay, on the other side, after a 4 cm air gap (on battens), a 1 5 mm sound protection panel and in the second wall a 58 mm Ecopanely (straw) was used: Both showed a Rw = 57 dB

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

021 Soundprotection: Outer walls single-shell and multi-shell Holzforschung Austria (HFA) has tested single-shell and double-shell walls (the wall structures are available in an online catalog on dataholz.com). Test single-shell Walls: •The impact of structural wood thickness on the singular details of airborne sound insulation is low. For example, in the case of a ventilated exterior wall, the superstructures with 1 20 mm and 240 mm thick construction wood differed only by DR w = 3 dB in the rated sound reduction index. •The effect of cavity attenuation in the installation level of timber frame walls on the singular number of airborne sound insulation is not detectable in the technically insulated construction level. • A variation of the fiber insulation materials used for cavity damping results in comparable bulk densities of the insulation material no change in the weighted sound reduction index R w of the wall construction. With regard to the lath arrangement, the following conclusions can be drawn for wooden facades: • If the battens are bolted or nailed directly to the construction wood, as is usual for structural reasons, this is extremely unfavorable in terms of sound insulation. By shifting the battens by 10 cm, so that the bolting of the battens only comes to rest in the wood-based panel, the weighted sound reduction index Rw increases by 4 dB to 5 dB. • If the battening is perpendicular to the structural timber and thus horizontal, the weighted sound reduction index Rw improves by 2 dB to 3 dB. • If the lathing is separated from the construction wood by a foam strip or a surfacebonded neoprene tape, this will only result in an improvement of 1 dB in the rated sound reduction index R w. Test double-shell Walls: Holzforschung Austria has investigated four different external thermal insulation composite systems (ETICS), whereby as plaster base panels facade polystyrene (EPS-F), elasticized polystyrene (EPS-FS), wood wool lightweight panels (WW-PT) and soft wood fiber boards (WF-PPTh) were used on wooden frame elements. The results can be summarized as follows: • ETICS with wood soft fiber and wood wool lightweight panels provide significantly better sound insulation dimensions R w (based on the single-number indication one notes improvements of 6 dB to 8 dB) as ETICS with polystyrene panels. • For ETICS with EPS-F, very different measurement results occur with the same construction set-ups. Cause is that crucial sound insulation characteristics, such as the dynamic rigidity is not a quality criterion in the production of facade panels. Scattering of up to 10 dB difference had to be determined.

INFO S4

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S4: Acoustics

INFO S4

022 Impact sound protection: Ceiling constructions In the case of impact sound insulation Ln,w timber construction is at a disadvantage due to its low component masses compared to mineral solid construction in the low frequency range. This can be compensated by the following measures: > Floating screed with high surface-related mass > Weighting of the construction by means of sand/gravel or heavy boards > Fixing of suspended ceilings [mass-spring] > Cavity insulation of beam ceilings with open-pore insulation materials Conclusion of the tests of the Holzforschung Austria: Installation levels with "closed shells" without insulation insert have a basically unfavorable effect on the airborne sound insulation as well as on the impact sound insulation. The best value with cavity insulation was achieved by an OSB planked soffit (Fig. 1 above). Similar or better impact sound insulation can be achieved even without suspended ceiling and cavity insulation ( 58 dB, see illustration below) See: dataholz.com

FIRE FEUER

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S5

Session Plan U6-S3: Flammability and Fire Resistance Objectives:

Flammability of straw Fire resistance of building components Fire tests, international & national examples

Methods:

Lectures Exercises Workshop

Trainer:

Place:

Classroom Workshop

Duration: 2 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Practice

Theory

Unterlagen: Lectures, charts, presentations ...

Incinerate lose straw in free area and compare with pressed matter. Find fire resistance values for different constructions in web, product declarations, etc. Compare different building regulations on aspects of fire resistance. Examine straw building regulations (German Strohballenbauregel, french,...) on aspects of fire resistance and security issues. Find admissions of your country relating to matters used in buildings.

Info Sheets: I1 Fire Resistance I2 Building Classes AT and EU (Fire Safety) Text Sheets: X1 Firetests X2 Zulassung von Bauteilen X3 Building Laws Powerpoint: Fire resistance & Regulations national and international Video/Bilder: FireTest

Organization:

U6 – BUILDING PHYSICS AND SUSTAINABILITY

INFO S5

Session Plan U6-S5: Flammability and Fire Resistance

023 Fire regulations: depending on the building class (GK)

The fire resistance class is given in accordance with the European REI classes of ÖNORM EN 1 3501 -2 for the calculation of the fire resistance of components: REI 30, REI 60 and REI 90, each number indicating the fire resistance in minutes which exposes a component to a fire after a unit temperature curve without failing. "R" is the criterion for the load bearing capacity, "E" for the area termination and "I" for the heat transfer through the component in the event of a fire. For straw bale walls, REI 30-90 can be achieved solely with the plaster thickness (F 30-B: 8 mm plaster on both sides, F 90-B, 30 mm plaster on both sides). Fire class: bales of straw correspond to Foire Class B2 (normally flammable) or building material class E, according to DIN EN ISO 11925-2) at a minimum density of 85 kg / m³ Fire regulations for Building Class 1 ( GK1 ) Floor Level (FOK) max. 7 m; max. 3 aboveground floors; max. 400 m2 total area; 1 apartment (WHG) or 1 building unit (BE); free standing In case of objects of GK1 for residential or office purposes, a fire resistance class of components (except basements, heating rooms, etc.) has been completely removed . This is due to the fact that, according to the statistical data, the safety of users of such objects does not depend on the fire resistance of the components used, but on the fact that they are warned in time. This circumstance was taken into account by the compulsory furnishing with smoke alarms (home smoke detectors, fire alarms). It will be of particular interest for timber constructions according to GK1 as well as for terraced houses which fall into GK2, for fireproof walls on the site or building site boundary (fire walls) a fire resistance duration of 60 min is enough. GK2: FOK max. 7 m; max. 3 aboveground floors; max. 400 m2 total area; max. 5 WHG or BE; terraced houses GK3 : FOK max. 7 m; max. 3 aboveground floors; max. 400 m2 total area; buildings, which are not GK1 –2 GK4: FOK max. 11 m; max. 4 aboveground floors; 1 BE or, if several WHG or BE, each max. 400 m2 total area In general, it should be noted that a fire resistance of 60 minutes was considered to be sufficient for objects of the GK2 and GK4, that is, up to an escape level of 11 meters (this means up to four above-ground floors) and thus an embodiment of combustible building materials should be economically possible, In some federal states, where the OIB directives have not yet been implemented, a limit of three floors above the ground is given here. GK5: FOK max. 22 m; buildings which are not GK1 –4; underground buildings For objects of GK5, ie up to the skyscraper limit, the respective top floor can be executed with a fire resistance duration of 60 min . In the case of building projects of up to six aboveground floors, the two uppermost floors can be executed in F 60, although 90 minutes are required. It should be noted here that a fire resistance class of 90 min may be required for stairs, escape ways, elevator, installation shafts and similar building parts. This has to be assessed project-related in planning. Only for buildings of building class 5 with more than six aboveground floors, the components must have a fire resistance of 90 minutes, with the exception of the uppermost floor, the essential load bearing components must be class A2 (nonflammable, no smoke, no falling down). Wooden constructions in buildings with more than six storeys are therefore only possible with additional compensatory measures; it is possible to use technical or structural measures such as an automatic fire extinguishing system (for example sprinkling ) or encapsulation of the wooden components.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S5: Flammability and Fire Resistance

INFO S5

Trittschallschutz: Deckenkonstruktionen

The MaterialprĂźfungsanstalt Braunschweig has issued a general building inspectorate test certificate for fire-retardant and fire-resistant, insulated exterior walls. Accordingly, layers of 8 mm clay or lime plaster are sufficient to achieve the fire resistance class "fire-retardant" F30-B according to DIN 4102. With 10 mm lime plaster on both sides, even the fire resistance class "fire-resistant" F90-B according to DIN 4102 can be achieved. Up to three-storey multi-family houses or office buildings with straw bale insulated walls can now be easily approved on the basis of this new general building inspectorate test certificate.

ROOM CLIMATE

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S6

Session Plan U6-S6: Health & Comfort in Indoor Climate Objectives:

Thermal comfort (radiation, temperature, air movement,...) Condition of personal thermal comfort due to activities and clothing (clo factor) Relative humidity comfort zone (winter, summer) The importance and principles of cold and heat protection in winter and summer Capacity of straw in thermal and humidity storage (advantage improving living comfort) Limits of acceptable amount of draft depending on temperature; Off-gassing of materials (VOC, MVOC) Relative humidity limits indoor to prevent organic matter from moulding

Methods:

Lectures Exercises Workshop

Practice

Theory

Lectures, charts, presentations ...

Trainer:

Place:

Classroom Workshop

Duration: 4 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Documents:

Info Sheets: I1 Health and comfortable Room Climate Powerpoint: Healthy Living and Room Climate

Working groups with 3â&#x20AC;&#x201C;4 participants working on detail examples Explain air-tightness measures on selected details. Measuring surface temperatures on different matters Measuring humidity Detecting leakages in building elements by simple methods Checking glass quality of windows by mirroring a flame

Organization:

Prepare workspace for participants with enough places and WiFi. Prepare copies of text sheets for multiple choice tests or have them online (e-learning). Prepare examples of details to work with in groups plus discussion Find different material resources for physical recognition (i.e. touching material with different Lambda value at same temperature (steel, insulation, wood, glass, etc.) radiation intensity examples.

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S6: Health & Comfort in Indoor Climate

SESSION PLAN S6

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S6

Session Plan U6-S6: Health & Comfort in Indoor Climate

024 Healthy Living and Room Climate

The main reason for the so popular and healthy indoor climate in straw bale houses is the clay plaster. It regulates the moisture balance (healthy room climate), stores heat (no large day and night fluctuations), cools in the summer by evaporation and is free of harmful outgassing , yes it even binds odors. Resdponsible for our well-being are also comfortable room temperatures ( good insulation , the lack of thermal bridges and well insulated windows as well as the airtightness of the building shell and the largest possible radiation heating (low temperature) and thus reduced convection in the room. In addition, with ideal planning ( solar architecture), solar radiation through windows also contributes (vice versa, outside shading must also be provided in summer). Natural building materials and surfaces (coatings) avoid (toxic or harmful) outgassing and electrostatic charges (such as plastic surfaces, vinyl, laminate, PVC) and vapor-permeable building materials ensure guaranteed mold-free constructions (assuming proper processing).

ENERGY

EFFICIENCE

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S7

Session Plan U6-S7: Energy Performance & Programs Objectives:

Energy performance declaration & programmes Discern between energy declaration, end-energy use, primary energy use. Alternative programmes like PHPP to calculate energy use more accurate and design in passive house or near zero energy standard and design houses also with better indoor climate (summer, ventilation, technical overheads, primary energy)

Methods:

Lectures Exercises Workshop

Trainer:

Place:

Classroom Workshop

Duration: 3 hours

Equipment:

Laptop Beamer (Projector) Flip chart Prepared examples

Practice

Theory

Documents: Lectures, examples, charts, presentations ...

Working groups with 3–4 participants working on detail examples Calculate U-values including Glaser (diagram) with programs (www.u-wert.net) Checking and understanding energy performance declarations See and understand a PHPP calculation example preferably compared with energy performance certificate of the same building. Finding freeware for EBPD Find your national regulations and compare with EU 2020 energy performance goals for buildings. What is still missing in that goals?

Info Sheets: I1 Energy Pass and Programs Text Sheets: X1 European Energy Code (Gebäude-Effizienz 2020) X2 EED X3 ENEV X4 PHPP X5 klima:aktiv Haus X6 Minergy (CH) Powerpoint: Energy Pass and Energy Efficiency

Organization:

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S7

Session Plan U6-S7: Energy Performance & Programs

025 Energy Pass and Energy Efficiency

The energy pass determines the assignment of a building to an energy class (A ++ to G). The classes differ with respect to the total energy requirements of a building. These include e.g. the electrical energy (light, operation of pumps ...) and gas, wood, coal depending on the heating system . When creating an energy certificate, the following is taken into account: The exact arrangement of all components enclosing the heated room - floor, ceiling, walls, windows, doors - is specified with its own heat transfer coefficient. At the same time, the components are assigned the standard U-values, so that one has actual and reference values of the building envelope. They are compared and result in the assignment to an energy class. The heat loss through these components is given in kWh/a . This measure based on the usable area plus wall base area excluding the insulating layer gives the energy consumption (heating demand) in kWh/mÂ˛a . The energy pass also provides information about the most important parameters such as primary energy demand , CO2 emissions and the total energy efficiency factor of a building (single-family house, multi-family house, school, office building, etc.) or part of a building (apartment, business premises, etc.).

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S7: Energy Performance & Programs

SESSION PLAN S7

required U-value (from 1974)

Energy Cost Comparison Straw Bale House and Massive Building according to ENEV

Source: lehmfinger.lima-city.de

SUSTAINABILITY

ENVIRONMENT

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S8

Session Plan U6-S8: Environmental Sustainability Objectives:

Embodied energy content (PEI) and CO 2 storage capacity of straw compared to other building matters (Baubook, acidification) Different land use caused by different traffic solutions plus energy consumption Ecological footprint for housing and traffic Importance of ecological performance in globalized world / climate Trainees can compare the ecological footprint of a straw building compared with conventional building techniques. Energy and material consumption for the building process Life cycle tools (i.e. eco2 soft)

Methods:

Practice

Theory

Lectures Exercises Workshop World Café Lectures, charts, ...

World Café Internet research Compare and evaluate PEI of different building methods CO 2 calculation of different matter Select and evaluate materials due to their ecological performance.

Trainer:

Place:

Classroom Workshop

Duration: 8 hours

Equipment:

Laptop Beamer (Projector) Flip chart Literature Prepared examples

Documents:

Info Sheets: I1 GWP of Baustroh/m³ I2 www.baubook.info I4 eco2soft LCA Powerpoint: GWP, UBP and Environmental Sustainability

Organization:

U6 – BUILDING PHYSICS AND SUSTAINABILITY

Session Plan U6-S8: Environmental Sustainability

U-Value and AP

Ökoindex (OI) and GWP

SESSION PLAN S8

U6 â&#x20AC;&#x201C; BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S8

Session Plan U6-S8: Environmental Sustainability

Primary Energy Demand (n.r.)

Difference PED in Heating years

SUSTAINABILITY

NACHHALTIGKEIT

U6 – BUILDING PHYSICS AND SUSTAINABILITY

SESSION PLAN S9

Session Plan U6-S9: Economical & Social Sustainability Objectives:

Economical type of buildings and housing schemes and their effect on different land use causing costs Energy levels of buildings plus their heating / cooling systems create different economic values and costs Sustainable economy and how straw bale buildings fit into it Regional, local, social and financial aspects of straw bale building Social cost of linear structured societies (covering every social affair with institutional or commercial providers instead of having community solutions) Time consumption of keeping a house in useable state

Methods:

Lectures Exercises Workshop World Café

Theory

Lectures, researches, ...

Place:

Classroom Workshop

Duration: 8 hours

Equipment:

Laptop Beamer (Projector) Flip chart Literature Prepared examples

Unterlagen:

Text Sheets: X1 Book tip: Günther Moewes, „Weder Hütten noch Paläste“ Powerpoint: Impulse Sustainability

Practice

World Café Internet research Workshop

Trainer:

Organization:

STEP – Straw Bale Training for European Professionals UNIT 6 – Building Physics & Sustaiability (201 7) Editor/Texts/Tips: Herbert Gruber (ASBN) Co-Workers: Helmuth Santler, Viktor Gach BuildStrawPro-Team (Erasmus+ Project), with texts from: TU Vienna, Institut für Architekturwissenschaften, ProHolz and FASBA (Dirk Scharmer, Burkhard Rüger). Design & Fotos: Herbert Gruber; more Fotos: Pexels, Illustrations/Icons: Michael Howlett (SBUK) This Handbook bases on the Handbook of the LeonardoTeam STEP (201 5)