Thermal measuring and testing – Determination of inherent thermal property – Thermal conductivity
Patent
1985-11-08
1987-03-03
Yasich, Daniel M.
Thermal measuring and testing
Determination of inherent thermal property
Thermal conductivity
374 30, G01K 1720, G01N 2518
Patent
active
046472215
DESCRIPTION:
BRIEF SUMMARY
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national phase application corresponding to PCT/CH85/00047 filed 20 Mar. 1985 and based in turn, upon a Swiss national application 1475/84-8 filed 23 Mar. 1984.
FIELD OF THE INVENTION
My present invention relates to a method of determining the thermal insulating properties of buildings, especially outer walls, by measuring the temperature drop between surfaces of the structure, particularly the inner surface and outer surface of the outer wall. The invention also relates to apparatus for this purpose.
BACKGROUND OF THE INVENTION
Increase in price and the foreseeable shortage of energy have drawn the problem of effective structural insulation against a loss of heat into the foreground. In these considerations, the dynamic heat transmission through the shell of the building is dominant; for this reason the thermal optimization of the shell of the building required as a central focus insulation against loss of heat, primarily by the reduction of heat transmission through the structural parts of the shell of the building by means of thermal insulation.
The areal thermal transmittance is characterized by the K-Value and mathematically determined according to present practice from the mathematical values of the thermal conductivity of the building materials. These values were, in turn, determined by numerous measurements. Note the article "Transmission of Heat By Conduction and Convection" by W. H. Adams in pages 92 and 93 of the Mechanical Engineers Handbook, Mc Graw Hill book Co., 6th Edition (1958).
The determination of the K-value can be an actual measurement from the thermal transmission of the structure. In construction engineering, one speaks, therefore, of the K-value measurement, which means precisely this thermal transmission measurement.
Since the K-value quantifies the thermal insulation capabilities of the structure, it can be defined by certain standards. The planner can follow these standard requirements accordingly. Inaccuracies in construction, alterations of the plans, utilization of building materials of different quality, uncoordinated working stretches etc. can, however, give rise to thermal insulation abilities (K-values) different from the original plan. The necessity for monitoring the heat transmission coefficient is therefore obvious.
The monitoring of the heat transmission of a building is particularly problematical because the measurement has to take place under non-steady state conditions, that is, under constantly changing temperatures and air currents as well as under changing thermal radiation conditions. The measuring of the K-value under these non-steady conditions takes place, then, by way of the heat flow measurement, whereby there are three prerequisites, namely: a constant heat flow direction over a long period a sufficient integration period in order to attain representative average values, and continual control of the measuring.
These three prerequisites lead to difficulties that make a routine execution of such measurments impossible because:
the known methods of measurement make measuring possible only in the cold season;
the natural mean temperature difference has to lie above 10 K.;
outside constructions bathed in sunshine connot be measured; and
an almost steady room temperature is required and only very long measuring times permit the determination of representative results.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to provide a method of measurement that can be generally and properly employed with the necessary accuracy of measurement, only slightly influenced by the boundary conditions.
Another object is to provide improved apparatus for this purpose.
SUMMARY OF THE INVENTION
This is achieved according to invention in that for generating a quasi steady or controlled non-steady condition in a measuring area, a temperature drop is forced thereupon so that, in comparison, the natural, non-steady state temperature drop can be disregarded.
In order to avoid imprec
REFERENCES:
patent: 3045473 (1962-07-01), Hager, Jr.
patent: 3075377 (1963-01-01), Lang
patent: 4059982 (1977-11-01), Bowman
patent: 4095454 (1978-01-01), Fisher
patent: 4236403 (1980-12-01), Poppendiek
patent: 4246785 (1981-01-01), Sellers et al.
"Transmission of Heat by Conduction and Connection" by W. H. McAdams, Mechanical Engineers Handbook 6th Edition, 1958, pp. 4-92 and 4-93.
Digana Ag
Dubno Herbert
Ross Karl F.
Yasich Daniel M.
LandOfFree
Method of and apparatus for the determination of the thermal ins does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of and apparatus for the determination of the thermal ins, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of and apparatus for the determination of the thermal ins will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1014449