Zbigniew Rymarczyk, Paweł Purgał – The Institute of Heating and Sanitary Technology in Radom

Mieczysław Dzierzgowski – The Warsaw University of Technology

2

Gable wall of a building

large slab system, the 70s (tex about –2 oC)

-2,0°C

7,0°C

-2

0

2

4

6

-2,0°C

7,0°C

-2

0

2

4

6

bad insulation of joints

reduced thickness of insulation

ceiling roof

lack of insulation in the prefabricated wall

inacurate placement of insulation material

3

Gable walls of buildings

large slab system, the 70s (tex about –2 oC)

-2,0°C

5,0°C

-2

-1

0

1

2

3

4

5

-2,0°C

5,0°C

-2

-1

0

1

2

3

4

5

the wall before warming up the wall after warming up

4

Test requirements– building envelopes of light construction, the Scandinavian conditions PN-EN 13 187-2001 standard: Thermal characteristics of buildings – Quality detection of heat faults in building walling – Infrared Method

The air temperature outside may change not more then 10 oC in comparison temperature at the beginning of the check for at least 24 hours since the beginning of tests,

The difference in air temperature on both sides of the building should not be smaller than 3/U, where U is a theoretical value of coefficient of heat permeability of building element, this difference cannot be smaller than 5º for at least 24 hrs before the beginning of tests and during it

It is recommended that the monitored wall surfaces should not be exposed directly to sun radiation for 12 hrs before the beginning of tests ,

During the check the air temperature outside should not change more than ± 5 º and the temperature inside not more than ± 2º in comparison to appropriate values at the beginning of tests

5

Air temperature inside and outside and difference between these two temperatures

Temperature of the air

-5,00

0,00

5,00

10,00

15,00

20,00

25,00

30,00

35,00

14:1

022

:55

0:10

1:25

2:40

3:55

5:10

6:25

7:40

8:55

10:1

011

:25

12:4

013

:55

15:1

016

:25

17:4

018

:55

20:1

021

:25

time

tem

pe

ratu

re [o

C]

tin oC

tex oC

Dt

6

„the air temperature outside may change not more than ± 10º in comparison to the temperature at the beginning of

the check for at least 24 hours since the beginning of tests”

The minimum temperature of the air outside in the period before the measurements was 1.8º C

The maximum temperature of the air outside in the period before the measurements was 10.8ºC

The temperature at the beginning of the measurements was 2.8ºC

The requirement was fulfilled

7

„The difference of air temperature on both sides of the building should not be smaller than 3/U, for at least 24 hrs

before the beginning of tests and during it”

The designed value of the coefficient of heat permeability = 0.55 W/m²K,

The difference between the air temperature inside and outside changed from 20.0ºC to 30.5ºC

The difference at the beginning of the test 27,4 oC

The requirement was fulfilled

8

„It is recommended that the monitored wall surfaces should not be exposed directly to sun radiation for 12 hrs before the beginning of tests ”

On the day before the measurement - there was overcast

the requirement was fulfilled

9

„During the check the air temperature outside should not change more than ± 5 º and the temperature inside not more than ± 2º in comparison to appropriate values at the beginning of tests ”

The air temperature during the check

0,00

5,00

10,00

15,00

20,00

25,00

30,00

35,00

22:1

022

:40

23:1

023

:40

0:10

0:40

1:10

1:40

2:10

2:40

3:10

3:40

4:10

4:40

5:10

5:40

6:10

time

tem

per

atu

re [o

C]

tin oC

tex oC

Serie10

10

„During the check the air temperature outside should not change more than ± 5 º and the temperature inside not more than ± 2º in comparison to appropriate values at the beginning of tests ”

The air temperature outside changed from 1.8ºC to 2.8ºC

The air temperature inside changed from 29.8ºC to 30.2ºC

the requirement was fulfilled

11

The device enabling the determination of heat resistance

of building envelopes

12

The basic technical data of the device

The frequency range of recording to memory – from 4 sec to 90 min

The maximum number of recorded measurements – 24 500

Channels 1 : 5 – heat sensors shaped as measurement plates of 120 mm x 120 mm

Channel 8 – converter of relative humidity, the measurement range 0...100% RH

Channels 9…18 – temperature sensors

13

The results of the device checkNumber of

chanelUnit Value Value of

referenceMeasured

value

k1 W/m2 10 mV 122,80 W/m2 122,9 W/m2

k2 W/m2 10 mV 115,10 W/m2 115,8 W/m2

k3 W/m2 10 mV 105,90 W/m2 105,5 W/m2

k4 W/m2 10 mV 113,90 W/m2 113,6 W/m2

k5 W/m2 10 mV 105,00 W/m2 105,3 W/m2

k8 % 12 mA 50,00 % 49,8 %

k9 oC 22 oC 22,0 oC 22,04 oC

k10 oC 22 oC 22,0 oC 22,05 oC

k11 oC 22 oC 22,0 oC 22,03 oC

k12 oC 22 oC 22,0 oC 22,05 oC

k13 oC 22 oC 22,0 oC 22,04 oC

k14 oC 22 oC 22,0 oC 22,05 oC

k15 oC 22 oC 22,0 oC 22,05 oC

k16 oC 22 oC 22,0 oC 22,05 oC

k17 oC 0 oC 0,0 oC -0,07 oC

k18 oC 0 oC 0,0 oC -0,07 oC

14

A photo and thermograms of a part of the wall with fitted sensors monitoring the heat flux density and the temperature on the inside

U3

U1 U4 U5

24,0°C

30,0°C

24

25

26

27

28

29

30

15

A photo and thermogram a part of the wall on the outside 

7,5°C

16,2°C

8

10

12

14

16

16

The changes of the heat flux density during the measurement

Changes heat flux density

0

5

10

15

20

25

30

35

40

45

50

22:1

022

:40

23:1

023

:40

0:10

0:40

1:10

1:40

2:10

2:40

3:10

3:40

4:10

4:40

5:10

Time

Hea

t fl

ux

den

sity

[W

/m2]

q1

q3

q4

q5

17

Thermal resistance of the parts of the wall

1,60 1,55

0,61

1,65 1,63

0,67

1,59

0,64

1,62

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

Place 1 Place 4 place 5

Th

erm

al r

esis

tan

ce (

m2. K

)/W

Rmin

Rmax

Rśr

18

Deviation of heat resistance from an average value in the place of measurement

-1,40

-2,40

-3,20

1,502,10

4,40

-4,00

-3,00

-2,00

-1,00

0,00

1,00

2,00

3,00

4,00

5,00

place 1 place 4 place 5

Dev

iati

n o

f h

eat

resi

stan

ce [

%]

Min. value.

Maks. value

19

Final remarks as regards the assessment of thermal insulation:

The research into thermal insulation of an object have practical significance for new erected and older buildings thermally modernized

It is recommended to combine classical measurement methods of the heat flux density and temperature with the thermography

20

Is it worth measuring the thermal resistance of building envelopes in real conditions? In the view of the C1152

standard: ”Determining heat resistance of building partitions on the basis of measurements conducted in situ” the answer

is positive:

For newly erected buildings — „the knowledge of thermal resistance of new buildings is important to determine whether the quality of constructin satisfies criteria set by the designer, by the owner, or by regulatory agency. Differences in quality of materials or workmanship may cause building components not to achieve design performance”

21

Is it worth measuring the thermal resistance of building envelopes in real conditions? In the view of the C1152

standard: ”Determining heat resistance of building partitions on the basis of measurements conducted in situ” the answer

is positive:

For the existing buildings – „knowledge of thermal resistance is important to the owners of older buildings to determine wheter the buildings should receive insulation or other energy – conserving improvements. Inadequate knowledge of the thermal properties of materials or heat flow paths within the construction or degradation of materials may cause inaccurate assumptions in calculations that use published date”

22

The use of thermography in the diagnosis of the central heating

installation

Determining the flow of water mass Other applications (pollution, the air

infection, hydraulic maladjustment, leak of heating element from the installation)

23

Application of thermography in the diagnosis of the central heating installation

The Water Mass Jet1. The mathematical calibration of a model of heat

exchange in the arrangement of “a heater – a heated room” on the basis of heat and thermographic research, at the stand for the research into heaters with an open type of chamber at The Warsaw University of Technology, including a calculation programme (radiator T1, 10 units)

2. Conducting the verification tests of heat and thermographic research of a heater at the stand for heat research into heaters with a closed type of chamber (radiator T1, 8 units)

24

3. Determining heat power of a heater and the water mass with the use of thermography and a computer software for a heater on the basis of the data acquired in point 2

4. Comparing the obtained results in accordance to points 2 and 3

Application of thermography in the diagnosis of the central heating installation

The Water Mass Jetcontinued

25

T-1 Heater – a photograph and construction

26

Technical data of T-1 heaterTotal height in mm 588

Fitting height between axis joints in mm

500

Width of a heater unit in mm 79,7

Building depth in mm 140

Outside surface area of 1 unit in m²

0,24

Water capacity of one cell in dm³ 1,18

Nominal mass of one cell in kilos 5,70

Number of units in the examined heater

8

27

The computer software designed at the Warsaw University of Technology makes it

possible to determine :

Temperature distribution along its height,

Heat power, [W] Average temperature of the surface, [oC]

28

Temperature of supply, return, air and mass jet in the function of time for a T1

heater in a chamber of an open type

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

80,0

90,0

00:00

:00

00:20

:00

00:40

:00

01:00

:00

01:20

:00

01:40

:00

02:00

:00

02:20

:00

02:40

:00

03:00

:00

03:20

:00

03:40

:00

04:00

:00

04:20

:00

04:40

:00

05:00

:00

05:20

:00

05:40

:00

06:00

:00

06:20

:00

06:40

:00

07:00

:00

07:20

:00

07:40

:00

08:00

:00

Time [h]

t[oC

]

0,000

0,005

0,010

0,015

0,020

0,025

0,030

0,035

M [

kg/

s]

t1

t2

ti

M

29

Thermograms of T1 heater a) flow 0.01409kg/sec b) flow 0.00638 kg/sec in an

open type of chamber

1. a)

IR - I0000000.028

89-05-01 05:00:20

50,0

90,0 °C

50

60

70

80

90

b)

IR - I0000000.027

89-05-01 04:08:23

50,0

90,0 °C

50

60

70

80

90

30

The test stand with a closed type of chamber – The Institute of Heating and

Sanitary Technology – Radom

Stand for research into heaters compatible with PN-EN 442-2:1999 standard

The Quality Assurance system in the laboratory in compliance with PN-EN ISO/IEC 17025:2001 standard “ General requirements as regards competence of research and standardization laboratories”.

31

The chart of a research

stand: 1 – circulation pump, 2 – tank, 3 – electric boiler, 4 – mixing device, 5 – overflow, 6 -valve, 7 –tested heater, 8 – flow regulating valve, 9 – heat exchanger, 10 –valve, 11 – valve, 12 – points of temperature measurements, 13 – measurement vessel

32

A thermogram obtained at the stand for heater tests with a closed chamber and the temperature profile obtained

experimentally and on the basis of a mathematical model

IR - I0 00 00 00 .0 05

1 90 0-02 -13 1 7:4 5:16

63 ,5

88 ,4 °C

6 5

7 0

7 5

8 0

8 5

0

100

200

300

400

500

600

700

40 50 60 70 80 90 100

temperatura [oC]

wys

oko

ść [

mm

]

wers ja I

termografia

33

Conclusion

Divergence between the water jet obtained on the basis of heat tests and the jet of mass obtained on the basis of a mathematical model and thermovision tests amounted to 4%

34

Heating – the water mass jet – real conditions

0,00485 kg/s – beafore cleaning 0,0435kg/s – after cleaning

1

2

3

4

IR - I0000000.004

97-02-05 20:57:48

20,0

50,0 °C

20

25

30

35

40

45

50

1

2

3

4

IR - I0000000.054

97-01-09 22:18:02

20,0

50,0 °C

20

25

30

35

40

45

50

35

35,0°C

55,0°C

36

38

40

42

44

46

48

50

52

54

35,0°C

55,0°C

36

38

40

42

44

46

48

50

52

54

SP01SP02

51,6 oC 40,9 oC

Heating – diagnostic of the central heating components - pollution

36

Heating – temperature distribution on the heater surface in the conditions of air infection of the central heating

installation

IR - I0 0 0 0 0 0 0 .0 2 6

2 4 -0 1 -9 7 1 5 :4 2 :2 1

4 0 , 0

9 0 , 0 ° C

4 0

5 0

6 0

7 0

8 0

9 0

IR - I0 0 0 0 0 0 0 .0 2 4

2 4 -0 1 -9 7 1 4 :2 8 :1 9

4 0 , 0

9 0 , 0 ° C

4 0

5 0

6 0

7 0

8 0

9 0

Heater with air infectonHeater after the process of

air removal

37

IR - I0000000.004

08-01-97 14:28:23

30,0

60,0 °C

30

35

40

45

50

55

60

30

35

40

45

50

55

60

0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4

długość grzejnika [m]

tem

pera

tura

[oC

]

IR - I0 0 0 0 0 0 0 .0 0 2

0 8 -0 1 -9 7 1 4 :2 4 :1 4

3 0 , 0

6 0 , 0 ° C

3 0

3 5

4 0

4 5

5 0

5 5

6 0

30

35

40

45

50

55

60

0,0 0,2 0,4 0,6 0,8 1,0

długość grzejnika [m]

tem

pera

tura

[oC

]

Heating – the distribution of temperature occurs in the

case of hydraulic deregulation

38

Heating- the central heating lines cause local increase in the surface temperature of the floor

IR - I0000000.013

97-01-08 15:26:23

23,0

33,0 °C

24

26

28

30

32

23,0

24,0

25,0

26,0

27,0

28,0

29,0

30,0

31,0

32,0

0 10 20 30 40 50 60 70

odległość [cm]

tem

per

atu

ra [

oC

]

39

Heating – leakage of the central heating components

out flow from the central heating installation

40

Final conclusion:

Simultaneously with insulation tests of building envelopes the theromgraphic method may be applied in heating for :

Estimating the water mass jet Preliminary diagnosis of units of the

central heating installation ( air infection, pollution, hydraulic deregulation, detection of installation leakage)