Department of Building Structures, CTU in Prague, Veronika BUREŠOVÁ, Michal BUREŠ HYGROTHERMAL BEHAVIOR OF WOOD BASED STRUCTURES - FULL SCALE EXPERIMENT

CONTENT  Introduction  Design of the experiment  Experimental facade  Results of the measurement

MOTIVATION  OBJECTIVE  Verifying the real hygrothermal behavior of enclosing structures  QUESTIONS  What are the temperature and humidity conditions inside the structure?  Does the condensation occur and can the structure dry out?  What is the thermal inertia of the structure?  Do parametres change due to aging?  How can the structure deal with a moisture disorder, eg. leaking?  COMMON METHODS  Calculations  Measurements at a construction site - in situ  Laboratory measurements

BACKGROUND  Annual increase in the number of wooden buildings by 40 % in the Czech Republic  Diffusion-closed structures (nearly impermeable layers)  Diffusion-open structures (vapor retarders)  Devaluation of wood – biotic pests:  wood-destroying instects  wood-decaying fungi  wood –staining fungi  molds  bacteria Source:

EXPERIMENTAL FACADE  What's going on?  UCEEB ->  „Big climate chamber“:  Room with controlled indoor environment  Efficient air-conditioning keep steady indoor conditions  Put into operation in March 2015

EXPERIMENTAL FACADE  Real outdoor environment  West orientation, Location: Buštěhrad (near Prague)  Monitoring of external environment – 3 weather stations  6 experimental areas: size of 3 x 3 m -> up to 24 samples 1,5 x 1,5 m  This experiment:  1 area divided into 4 samples

CONSTRUCTIONAL SOLUTION  Modern wooden buildings  diffusion-open structures (3x) / diffusion-closed structure (1x),  contact structures with plaster (2x) / naturally ventilated structures with timber cladding (2x)  inner insulation mineral / celulose / natural  timber frame structures with OSB from the inner side, with a cavity for installations closed with gypsum boards  4 different compositions of building envelope

CONSTRUCTIONAL SOLUTION

MEASURING  Measuring equipment  Over 700 usable sensors in the all facade ->  64 pieces of sensors measuring 92 parameters in this area  Time step – 5 min.

CONSTRUCTIONAL SOLUTION

ONGOING MEASUREMENT  Moisture content in the wooden frame

ONGOING MEASUREMENT  Relative humidity in the thermal insulation between the frame

ONGOING MEASUREMENT  Heat flux  Phase shift (8-12 h)

ONGOING MEASUREMENT  Temperature and relative humidity in the outer layers of two compositions with plaster  P3: mineral wool x P4: EPS

CONCLUSIONS, DISCUSSION  continuation: other compositions (wood fiber board)  comparative experiment in climatic chamber  next step: moisture load  Just a beginning!

THANK YOU FOR ATTENTION!  