Status and current activity



Fundamentals of moisture buffering

Properties of hygroscopic materials

Diffusion enhanced materials and structures

Experimental: Sorption experiments

Experimental: Diffusion experiments

Diffusion rate discussion

Incorporating the buffer in the construction

Whole room simulations and experiments

Experiment in the Passys environmental room

Whole building considerations



Appendices - instruments and procedures
Tinman instructions and results

Bibliography and references

Page for discussion

Wiki howto

Live data from the environmental chamber measuring moisture buffer performance of materials and constructions

The chamber is currently idle. Its most recent activity was measuring vapour diffusion within absorbent insulation subjected to a temperature gradient and with a fixed RH at the cold side. The purpose was to determine the driving force for diffusion: is it driven by vapour pressure difference, by vapour concentration difference or by relative humidity, and is there an independent effect of temperature difference? The researcher is Thor Hansen. The results are reported as Moisture transport through a porous material in a temperature gradient.

This chamber is operating in the Civil Engineering Department of the Technical University of Denmark, Lyngby. It controls either the RH, or the water vapour flux, in a specimen chamber capable of containing sections of walls of buildings. Instead of weighing the specimen to measure water exchange, it weighs the water in a reservoir in the vapour tight enclosure.

Download filtered data as text file

Diagnostic information

Today's complete data stream at one minute interval, as text (earlier data are preserved on the server)

[Note: the image above is in higher resolution than is displayed. Right click (usually) to show full size image.]

This is a picture of the interior of the climate chamber with an earlier test subject - unfired bricks with perforations exposed to the chamber air. The shiny metal in the bottom half of the picture is the water vapour flux generator. The surrounding circular structure is a double walled, insulated chamber with temperature control by air circulating over cooling coil and heating coil within the annular space.

The purpose of this experiment is to evaluate the performance of water vapour reactive materials in a cyclic variation in RH.

Here is an article describing results from the previous set of experiments and the accompanying lecture.

Read the Discussion of results (pdf 5Mb)

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Page last modified on April 23, 2016, at 12:05 PM