Ingenieurbüro Arbeitsgestaltung und Baubiologie Peter Rauch
(This page was automatically translated from German. Wärmespeicher2)

Stored solar-energy at an outside-wall


Thermometry at a building-outside-wall in December 2002

In the measuring-protocol by February 2001, it will describe the setup and the implementation extensively. This measurement is used for the already achieved measuring results as comparison. In the time limit, the outside-temperatures lay with about in the night. -13 to -14 ºC. The measured outside-temperatures were grasped directly at the building-outside-wall.

Table

2-temperature-proceeds at an outside-wall-plain in the time of the 11.12. until

13.12.2002Wandaufbau: 2 cm of lime-finery, 25 cm of brick, 2 cm of inner-finery, inner-heat insulation, 2 cm of Styropor and gypsum-construction-plate

Remark

Time

Raumtemp.

Oberfl. Interior

10cm from outside

Oberfl. Outsides

A.-temp.

A.-temp.2

Sun

12.00

18,4

15,7

-4,4

1

-4,6

10

Sun until 14.30

14.00

19,5

16,5

-2,2

0

-4,4

8

 

15.00

21

17,8

-2,1

-3,8

-4,8

-3

 

17.00

18,8

18

-3

-4,5

-6

-5

 

 

 

 

 

 

 

 

 

8.30 o'clock

18,6

17,4

-5,7

-6,5

-8

-7

Sun from 8.45

10.00

19,3

17,9

-5,9

-4,8

-5,6

-2,5

 

12.00

21,2

19,2

-3,4

0,5

-3,8

11

 

14.00

20,7

18,6

-1,2

1,2

-2,9

11

Sun until 14.30

15.45

20,2

18,6

-0,5

-2,4

-2,9

-2

 

17.30

20,7

18,6

-1,7

-2,7

-4

-4

 

 

 

 

 

 

 

 

Sun from 8.45

9.00

19,2

17,6

-5,4

-5,8

-8

-8,8

 

12.00

18,4

17,3

-3,1

0,6

-4,8

9

 

13.45

18,6

17,6

-1,5

-2

 

10

Sun until 14.30

15.45

20,5

 

-1

-2,9

-4,3

-3

 

17.30

19,7

 

-1,7

-4

-5,3

4,5

The measured outside-temperature corresponds approximately (all influential factors don't let themselves turn off) to the temperature without direct sun-no-radiation. The 2. Outside-temperature is available with a direct irradiation through the sun.
The sun-no-radiation took place something covered through the branches of a tree until about 11.00 o'clock from 8.45 o'clock and then directly until 14.45 o'clock.


Temperature [in ºC]
Temperaturverlauf an einer Außenwand

Opposite the measuring-implementations in February 2001, the outside-air-temperature now was measured in the shadow. The temperature-alteration on the day is shown (4 to 5 K) by it lower. The temperature-alteration of the outside-air on the sun-page is with about. 20 K. The air-temperature increased directly at the building between 4 to 5 K on the day. The alteration of the surface temperature through sun-no-radiation is with 7,5 K. The temperature-increase 10 cm in the wall-inside lies with cirka's 5 K. In February, this value was with about. 8 to 11 K.
Now, essentially less measured values were grasped what leads to more inaccurate values. Still, the sun-stand is higher in February and the direct and indirect sun-no-radiation longer, so that also the solar energy-profit margins are bigger.

As was represented already in the protocol of February, this outside-wall is no optimal construction with reference to heat-storage and thermal conductivity. Nevertheless, a heat flux clearly is inwards recognizable from outside on the day.

For a clear evaluation of the solar energy-production of a massive outside-wall, long-temporal measurements are necessary preferably over the entire year. 4 different outside-temperatures (temperature outside the radiation-area of the building, air-temperature at the building with and without heliation, the surface temperature, outside) should on that occasion, 3 to 5 temperatures in the wall-cross section, that are grasped interior-temperature and the wall-surface temperature (interior). The measuring-consequence should take place at least 1/2 every hour. The measurement should include on that occasion as also as possible at different buildings and wall-constructions (massively Konstrutionen, easily-construction-constructions and dammed facades). Thermometries for the provision of heats flux are not simple and are subject to many undesirable sturgeon-sources. Here, the different measuring processes should be combined.
All previous measurements are limited in winter-months and on a massive wall-construction usually only on few hours. The temperature-course in the wall-cross section and the surface temperatures (contact-surface) were not grasped measuring-technically. Measured air-temperatures at the wall-surface don't result in any real picture over non-stationary heats flux. Add on top of this that is required not only in the winter of Heizenergie but also on less warm summer-days. There, already the stored solar heat often bridges the 2 to 3 cooler day. With longer direct and indirect sunshine, also the stored solar heat quantity changes. As well, the idea-corner is not to be underestimated. However, a calculated wall-construction after the glazier-law case can must work without fail in the practice. This completely simply has to do with it that only some values (usually also determines only in the laboratory) are taken into account with this method of computation. As well, non-stationary dampness-streams are not grasped, that emerge. A part of the cirka 50 influential factors remains unconsidered since these cannot be grasped measuring-technically or are not at all known.

Literature sources, links and further implementations


Ingenieurbuero Peter Rauch

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