FLOOR HEATING ++ Lecture 2c

FLOOR HEATING ++ 

Lecture 2c 

• Bjarne W. Olesen, Ph.D. 

• Professor, 

• International Center for Indoor Environment 

and Energy 

15/02/2009 Bjarne W. Olesen, ICIEE-DTU 1 

Radiant surface heating 

and cooling systems 

Floor Wall 

Thermo Active Building Systems 

Floor 

Reinforcement 

Ceiling 

Room 

Window 

Concrete Room 

Pipes 

Room 

Pipes 

15/02/2009 Bjarne W. Olesen, ICIEE-DTU 2

Determination of Heating and 

Cooling Capacity 


STANDARDS 

• prEN 1264-2, 2007: Prove methods for the determination of the thermal 

output of floor eating systems using calculation and 

test methods 

– EN 1264-1, 1999: Floor heating: Systems and components - Part 1 : 

Definitions and symbols 

– EN 1264-3, 1999: Floor heating: Systems and components - Part 3 : 

Dimensioning 

– EN 1264-4, 2001: Floor heating: Systems and components - Part 4: 

Installation 

• prEN 1264-5, 2007: Heating and cooling surfaces embedded in floors, 

ceilings and walls — Determination of thermal output and 

cooling output 

• EN15377-1, 2007: Embedded water based surface heating and cooling 

systems: Determination of the design heating and 

cooling capacity 


systems: Design, Dimensioning and Installation 


systems: Optimizing for use of renewable energy sources 


SURFACE HEATING AND 

COOLING 

Heat transfer coefficient 

Heating 

Cooling 

11,0 

7,0 

Floor 

6,0 

11,0 


8,0 

Ceiling 

Floor heating and Ceiling cooling: q = 8,92 (θ S,m - θ i ) 1,1 

Wall heating and Wall cooling: q = 8 ( θ S,m - θ i ) 

Ceiling heating: q = 6 ( θ S,m - θ i ) 

Floor cooling q = 7 ( θ S,m - θ i ) 

Where 

q is the heat flux in W/m2 

θS,m is average surface temperature 

is room design temperature (operative) 

θ i 

8,0 

11,5 

10,5 

9,5 

8,5 

7,5 

6,5 

5,5 

Wall 


COOLING 

Heat transfer coefficient 


W/m 2 K


COOLING 

Max. - Min. Surface temperature 

Heating Cooling 

29 

20 

Floor 

35 

20 


27 

17 

Perimeter 

40 

17 

Ceiling 

45 

40 

35 

30 

25 

20 

15 

Wall 

MAXIMUM HEATING AND 

COOLING CAPACITY 

Heating 

Cooling 

99 

42 

Floor 

165 

42 


42 

99 

Perimeter 

160 

72 

Ceiling 

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

Wall 

o C 

W/m 2

Universal single power function 

(EN1264) 

FLOOR HEATING 

• CALCULATION OF THE HEAT OUTPUT W/m² 

• System factor B will depend on type of system and type of pipe 

System constant~ 6.5 - 6.7 Factors 

Temperature difference 

(Room - water) 

m 

B T 

m 

D 

T D u 

Ba aaat Floor covering Pipe spacing Pipe diameter Screed covering 



m 

u 

HEATING CAPACITY 

• Floor covering a B, spacing a T, and covering 

a D factors in tables 

• mT = 1- T/0.075 (T = Pipe spacing, m) 

• mu = 100 ( 0.045 - su )(su = covering thickness, m) 

• mD= 250 ( D-0.020 ) (D = Pipe diameter, m ) 

w

Table A.1 : Floor covering factor a B depending on the thermal resistance R ,B of the floor covering 

and the thermal conductivityE of the screed for type A and C systems 

R ,B 

(m2K/W) 0 0,05 0,10 0,15 

E 

(W/(m.K)) a B 

2,0 1,196 0,833 0,640 0,519 

1,5 1,122 0,797 0,618 0,505 

1,2 1,058 0,764 0,598 0,491 

1,0 1,000 0,734 0,579 0,478 

0,8 0,924 0,692 0,553 0,460 

0,6 0,821 0,632 0,514 0,433 

NOTE : The floor covering factor a B may be determined with 

the following equation: 

a 

B 

1 su,0 

 

u, 

0 

 

1 su, 

0 

R 

 

E 

, 

B 

where = 10,8 W/m2K;u,0 = 1 W/m.K; s u,0 = 0,045 m 



HEATING CAPACITY 

1.50 

1.00 

0.50 

0.00 

FACTOR FOR FLOOR COVERING, a B 

0.49 

0.46 

0.15 

0.1 

0.60 

0.55 

m 2 K/W 

0.76 

0.69 

0.05 

1.06 

0.92 

1.20 

0.80 

Screed 



• Total factor for the following example 

• 17 mm pipe 

• 45 mm concrete above pipes 

1 

• Concrete ~ 1,2 W/mK 

0,8 

0,6 

0,4 

0,2 

0 

300 

0,42 

0,52 

T, mm 

150 

0,57 


0,77 

0,66 

75 

0,96 

0 

0,01 

0,1 Rb, m 2 K/W


• Cooling capacity in W/m²for the following example 

• 17 mm PEX-pipe 

• 45 mm concrete above pipes 50 

• Concrete ~ 1,2 W/mK 

• Space temperature 26 °C 40 

• 

• 

Supply water temperature 14 °C 

30 

Return water temperature 19 W/m°C 20 

2 

10 

0 

300 

20 

25 


Heat exchange [W/m2] 

T mm 

150 

ALUMINUM HC device: Floor Heating & Cooling (type B), R=0.01~0.1, 

T=150 & 300 

160 

140 

120 

100 

80 

60 

40 

20 

0 

T=150, R=0.01 

T=150, R=0.1 

T=300, R=0.01 

T=300, R=0.1 

27 

37 

75 

32 

46 

0,1 

0,01 

R b m 2 K/W 

Heating/ cooling capacity, EN1264 

and EN 15377 

-15 -10 -5 0 5 10 15 20 25 30 

Heating/cooling medium differential temperature ΔθH=θH-θi [°C] 

Figure 4.17 Heat exchange between the surface (with ceramic tiles, wooden 

parquets or carpet R?B=0.1 and no covering R?B=0) and the space when aluminium 

heat conductive device used 


Thermal resistance methods 


Pipes embedded in a 

massive concrete layer 


Thermal resistance method 

 

v 

R t 

R 1 

R 2 



 

 

c 

q 1 

q 2 

s 1 

s 2 

Capillar tubes

v R t 

Thermal resistance 

methods 

R 1 

R 2 


 



 

 

 

c 

s 

2



q K Δθ 

i 

K H 

Thermal resistance 

methods 

H 

H H i 

H 

W/m 

² 

is the differential temperature of the heating/cooling 

medium 

equivalent coefficient of thermal 

conductivity 

/( RHC 

R ) W/m² 

C 

KH 1 

i 

Total thermal resistance between the heat source and the 

conducting layer 

m² °C/W 

T 

RHC T 

RR 

T 

RR 

, con RU 

R 

2 


R HC 

CL 

R i 

R e


Finite Element Method 


Laboratory testing 


UNIFORMITY OF FLOOR SURFACE 

TEMPERATURE 

Maximum 

Mean 

Minimum 


W/ 2 m 

RADIANT FLOOR COOLING 


155 

135 

115 

95 

75 

55 

35 

15 


CALCULATED CAPACITY IN AN ATRIUM 

WITH DIRECT SUNSHINE ON THE FLOOR 

107 


129 

148 

25 20 15 

Supply water temperature, o C

Floor surface temperature 

Heating/ cooling capacity, EN1264 and EN 15377 

Heat exchange [W/m2] 

ALUMINUM HC device: Floor Heating & Cooling (type B), R=0.01~0.1, 

T=150 & 300 

160 

140 

120 

100 

80 

60 

40 

20 

0 

T=150, R=0.01 

T=150, R=0.1 

T=300, R=0.01 

T=300, R=0.1 

-15 -10 -5 0 5 10 15 20 25 30 

Heating/cooling medium differential temperature ΔθH=θH-θi [°C] 

Figure 4.17 Heat exchange between the surface (with ceramic tiles, wooden 

parquets or carpet R?B=0.1 and no covering R?B=0) and the space when aluminium 

heat conductive device used 


Floor covering 

Heat supply 

Pipe distance 

T water-average –t room 

Diagram for 

17x2 mm pipe 

45 mm screed 

= 1,2 W/mK 


Water flow rate 

Pressure drop 

Water 


The design supply water 

temperature is determined 

according to the room with the 

highest heat load or with the highest 

heat resistance of the floor covering. 


Calculation of the water supply temperature 

Heat resistance of the floor covering R ,B = 0,15 m 2 K/W 

Pipe spacing 15 cm 

Design heat loss 80 W/m 2 

From the dimensioning diagram 

Difference between average water temperature and room: 

H = 28,9 K 

Average water temperature: 

HM= 20°C + 28,9 K = 48,9 °C 

Temperature difference (supply-return) for the critical room: EN1264 = 5 K 

Design supply water temperature: 

Vdim = HM + /2 = 48,9°C +2,5 K = 51,4 °C 


80 W/m 2 

FB= 27,3 °C 

0,15m 2 K/W 

Diagram for 

dimensioning 

H 

HM 

= 28,9°C 

= 48,9 °C 

Vausl = 51,4 °C 

Boundary 

conditions 

S å = 45 mm 

å = 1,2 W/mK 


DIMENSIONING AND 

DESIGN 

• Pipe diameter 

• Pipe spacing 

• Pipe layout 

• Water flow rate 

• Pipe circuits 


Kombizone 


RL 

VL

Perimeter and occupied space 


Occupied space 


RL 

VL 

RL 

VL 

RL 

VL

VL 

RL 

Cover as much surface as possible 

Possible solution 




Joints in the concrete 


R 

L 

V 

L

Example 


Correction for covered 

surface 

Floor area 

Korrektur af 

Normvarmetabet 

Største varmestrøm 

Bad tages ikke med 


Tilslutningsledninger 

Varmeafgivel se [W/m] 

egen varmekreds 

gennemgående 

Total rørlængde 


15 

14 

13 

12 

11 

10 

9 

Forbindelses rör 

45 46 47 48 49 50 51 52 53 54 55 56 57 58 

Dimensionerende fremlöbstemperatur [°C] 

45 mm Beton, Ü = 1,2 W/mK 


q 

r 

Vandstrøm: 

Water flow 

 

0, 

86 

c 

TFTR TF 

TR 

qr: Water Vandstrøm flow l/h 


 

 

c: Vands varmefylde Wh/kgC 

Specific heat capacity 

Φ: Heat Varmeydelse supply W 

Tryktabsdiagramdiagram 

for 17 x 2 mm rør 


14 

Water flow rate 

Pressure drop 14 x 2 mm 

pipe 

Pressure drop 

Water 


5 1 / 4 

Valve 

position 


Valve position 


INSTALLATION 

• Floor systems 

• Wall systems 

•Ceilingsystems 

• TABS Thermo Active Building Systems 

• Pre-fabrication 


1. Screed-concrete 2. Pipe 

3. Plastic foil 

4. Insulation 5. Acoustic insulation 

6. PE foil 

7. covering 8. Concrete slab 





Radiant surface heating 

and cooling systems 

Floor Wall 

Thermo Active Building Systems 

Floor 

Reinforcement 

Ceiling 

Room 

Window 

Concrete Room 

Pipes 

Room 

Pipes 



Calculation methods 

1. Rough sizing method based on a standard 

calculation of the cooling load (accuracy 20-30%). 

To be used based on the knowledge of the peak 

value for heat gains (section 5.1) 

2. Simplified method using diagrams for sizing 

based on 24 hours values of heat gains (accuracy 

15-20%, section 5.2). 

3. Simplified model based on finite difference 

method (accuracy 10-15%). Detailed dynamic

FLOOR HEATING ++ Lecture 2c

Create successful ePaper yourself

Delete template?

Save as template?