COOLING AND HEATING OF BUILDINGS BY ACTIVATING THE THERMAL MASS WITH EMBEDDED HYDRONIC PIPE SYSTEMS • Bjarne W. Olesen, Ph.D., • Head of R&D, Wirsbo-VELTA, Germany • Professor, Technical University of Denmark EMBEDDED PIPE SYSTEMS Max. - Min. surface temperatures 40 17 27 17 35 20 29 20 15 20 25 30 35 40 45 Floor Ceiling Wall o C Heating Cooling Perimeter SURFACE HEATING AND COOLING Heat transfer coefficient 8,0 8,0 6,0 11,0 11,0 7,0 5,5 6,5 7,5 8,5 9,5 10,5 11,5 Floor Ceiling Wall W/m 2 K Heating Cooling COOLING CAPACITY • Cooling capacity in W/m²for the following example • 17 mm PEX-pipe • 45 mm concrete above pipes • Concrete ~ 1,2 W/mK • Space temperature 26 °C • Supply water temperature 14 °C • Return water temperature 19 °C 75 150 300 0,01 0,1 25 37 46 20 27 32 0 10 20 30 40 50 W/m 2 T mm R b m 2 K/W Max. heating-cooling-capacity 160 72 42 99 165 42 99 42 0 20 40 60 80 100 120 140 160 180 200 Floor ceiling wall Heating Cooling Perimeter W/m 2
Transcript
Seite 1
COOLING AND HEATING OF BUILDINGSBY ACTIVATING THE THERMAL MASS
WITH EMBEDDED HYDRONIC PIPE SYSTEMS
• Bjarne W. Olesen, Ph.D.,• Head of R&D, Wirsbo-VELTA, Germany• Professor, Technical University of Denmark
EMBEDDED PIPE SYSTEMS
Max. - Min. surface temperatures
40
17
27
17
35
20
29
20
15
20
25
30
35
40
45
Floor
Ceiling Wall
oC
HeatingCooling
Perimeter
SURFACE HEATING AND COOLINGHeat transfer coefficient
8,08,0
6,0
11,011,0
7,0
5,56,5
7,5
8,5
9,5
10,5
11,5
Floor
Ceiling
Wall
W/m2K
HeatingCooling
COOLING CAPACITY• Cooling capacity in W/m²for the following example• 17 mm PEX-pipe• 45 mm concrete above pipes• Concrete ~ 1,2 W/mK• Space temperature 26 °C• Supply water temperature 14 °C• Return water temperature 19 °C
75150300
0,01
0,1
25
3746
2027 32
0
10
20
30
40
50
W/m2
T mm
Rb m2K/W
Max. heating-cooling-capacity
160
72
42
99
165
42
99
42
020406080100120140160180200
Floor
ceiling wall
HeatingCooling
Perimeter
W/m2
Seite 2
RADIANT FLOOR COOLING
No cooling - decreased performance Low energy costs Low operation costs
Constant temperature Draught Noise SBS High energy costs High operation costs
Temperature ramps Reasonable energy costs Low operation costs
• Offices, schools, commercial buildings• Heat storage/transfer between day and
night• Heat transfer between south and north
facing rooms ?• Use of dynamic computer simulations ?
Seite 7
COMPUTER-SIMULATION COMPUTER-SIMULATION
COMPUTER-SIMULATION
CONTROL OF A COMBINED FLOOR HEATING-COOLING SYSTEM
Boiler Chiller
Room temp.-Humidity
Outside temp.
SupplyLimiter
ReturnMixing valve
Valves
VIVALDI
Operation time
Mai to SeptemberMean water temperature according to
outside temperatureOperation 24 hours
090518 – 60901
22-60902
°C % % %
<20 0,0 0,0 0,0
20-22 11,3 3,9 1,8
22-25 88,0 87,6 91,6
25-26 0,7 6,3 5,1
26-27 0,0 1,7 1,3
Temperatureinterval
>27 0,0 0,5 0,1
hours 1217 515 412Pump running
% 33 14 11
ART MUSEUMBREGENZ
Seite 8
ART MUSEUM IN BREGENZ
• Design requirements– Air temperature variations during a day within 4 K– Relative humidity variations less than 6 % during a day.– Seasonal variations between 48 and 58 %– Room temperature in winter 18 oC to 22 oC– Room temperature in summer 22 oC to 26 oC, occasional up to 28 oC
4th floor window west 4th floor window south 5th floor window west5th floor window east 5th floor middle meeting roomall offices except middle
STUTTGARTBUILDING 3
0
10
20
30
40
50
60
70
80
<1 (1-2) (2-3) (3-4) (4-5) (5-6) >6chan
ge in
ope
rativ
e te
mpe
ratu
re d
urin
g a
day
(8-1
8) [%
]
4th floor window west 4th floor window south 5th floor window west5th floor window east 5th floor middle meeting roomall offices except middle
Office building in Hamburg
• 2000• 14.000 m²• 7.500 m² slab cooling• Baseboard heaters• 2 ach, 18 °C• Operable windows
Transportation of modules
Seite 11
INSTALLATION
PRE-FABRICATION
PRE-FABRICATION
CONCLUSIONS
• Hydraulic heating/cooling system with pipesembedded in the building structure is aninteresting alternative to full air conditioning
– High temperature cooling-low temperature heating– No noise– No draught– Low installation and running costs– Lower peak load and reduced equipment size– Lower building height– Combined with mechanical ventilation– Reduced capacity?– Acoustic?– Latent load?
