EMBEDDED PIPE SYSTEMS. SURFACE HEATING AND COOLING Heat transfer coefficient COOLING CAPACITY. Max. heating-cooling-capacity

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1 COOLING AND HEATING OF BUILDINGS BY ACTIVATING THE THERMAL MASS WITH EMBEDDED HYDRONIC PIPE SYSTEMS EMBEDDED PIPE SYSTEMS Bjarne W. Olesen, Ph.D., Head of R&D, Wirsbo-VELTA, Germany Professor, Technical University of Denmark Max. - Min. surface temperatures SURFACE HEATING AND COOLING Heat transfer coefficient Heating Cooling 29 Floor Perimeter 17 Ceiling Wall o C Heating Cooling 11, 7, Floor 6, 11, 8, Ceiling 8, 11,5 1,5 9,5 8,5 7,5 6,5 5,5 Wall W/m 2 K COOLING CAPACITY Cooling capacity in W/m²for the following example 17 mm PEX-pipe 45 mm concrete above pipes Concrete ~ 1,2 W/mK 5 Space temperature 26 C Supply water temperature 14 C 37 Return water temperature 19 C 27 W/m T mm 46 32,1,1 R b m 2 K/W Max. heating-cooling-capacity wall ceiling Perimeter Heating Cooling Floor W/m 2

2 RADIANT FLOOR COOLING COMFORT-PERFORMANCE 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 COMFORT-PERFORMANCE THERMAL COMFORT People 1 Energy 1 OPERATIVE TEMPERATURE -,5 < PMV < +,5 ; PPD < 1 % SPACES WITH MAINLY SEDENTARY OCCUPANTS : SUMMER CLOTHING,5 clo ACTIVITY LEVEL 1,2 met 23 C < t o < 26 C. EN-ISO 77 COMFORT CRITERIA Definition of comfort conditions according to DIN 1946 CR 1752 Class Comfort requirements Temperature range PPD PMV Winter Summer 1. clo clo 1.2 met met [%] [/] [ C] [ C] Allowed temperatures Optimal range A < < PMV < B < < PMV < C < <PMV < Allowed temperatures

3 Airport Bangkok Airport Bangkok Figure 2 Figure 1 Temperature in C Figure 3 SBIA Concourse Case 1 East-West oriented, Fritted Glass 76% -> % constant temperature of 13 C for floor cooling realistic schedules for occupancy Ambient Air (Conditioned Levels) Air (Lower Unconditioned Zone) Air (Higher Unconditioned Zone) Floor Cooling Inlet Floor Cooling Outlet Surface of Cooled Floor Operative Temperature Cooling Power in kw Figure 4 SBIA Concourse Case 2 East-West oriented, Fritted Glass 76% -> % constant inlet temperature of 13 C for floor cooling realistic schedules for occupancy Total Sensible + Latent Load Total Sensible Cooling Load Floor Cooling Fluid Sensible Cooling Recirculating Air Sensible Cooling Supply Air Dehumidifcation Supply Air

4 Figure 5 Figure 6 Cooling Power in kw SBIA Terminal Building Cooling loads for Terminal Building realistic schedules for occupancy Total Sensible + Latent Load Total Sensible Cooling Load Floor Cooling Fluid Sensible Cooling Recirculating Air Sensible Cooling Supply Air Dehumidifcation Supply Air Temperature in C SBIA Terminal Building upper level, check in realistic schedules for occupancy Ambient [ C] Air (Conditioned Levels) [ C] Air (Lower Unconditioned Zone) [ C] Air (Higher Unconditioned Zone) [ C] Floor Cooling Inlet [ C] Floor Cooling Outlet [ C] Surface of Cooled Floor [ C] Operative Temperature [ C] Figure 7 FIGURE 8 Airport Bangkok OPEN AIR THEATER BREGENZ

5 OPEN AIR THEATER BREGENZ BREGENZ Sky-light Window ROOM 4 Pipes Hall Window ROOM 4 Steel support OPEN AIR THEATER BREGENZ BREGENZ Operative Temperatur Aussentemperatur Büro 4 To Flur To Büro 4 To Temperatur [ C] : : : : : : : : Zeit BUILDING 1 Hallway Room 4 Room 4 Room 414 Total for rooms 4, 4, 414 CONCRETE SLAB COOLING/HEATING Percentage of operative temperature according to DIN 1946 [%] < >27 Floor Insulation Concrete Reinforcement Room Room Window Pipe

6 CALCULATED TEMPERATURES CALCULATED TEMPERATURES Calculated cooling-heating capacity CALCULATED TEMPERATURES Cooling Heating Supply water temperature: 16 C C Return water temperature: C Space temperature: 26 C C Floor : 9 W/m 2 5 W/m 2 Ceiling : 39 W/m 2 14 W/m 2 Totat: 48 W/m 2 19 W/m 2 Floor : 9 W/m 2 5 W/m 2 Ceiling : 47 W/m 2 16 W/m 2 Total 56 W/m 2 21 W/m 2 Floor : 26 W/m 2 15 W/m 2 Ceiling : 37 W/m 2 14 W/m 2 Total : 63 W/m 2 29 W/m 2 CONCRETE SLAB COOLING/HEATING Building requirements Well insulated Window U-values < 1,2 W/m 2 K Solar shielding Cooling load ~-5 W/m 2 Heat load < W/m 2 only system W/m 2 < Heat load < W/m 2 optimal control W/m 2 < Heat load, additional system CONCRETE SLAB COOLING/HEATING Heating and cooling of multi-storey buildings Offices, schools, commercial buildings Heat storage/transfer between day and night Heat transfer between south and north facing rooms? Use of dynamic computer simulations?

7 COMPUTER-SIMULATION COMPUTER- SIMULATION COMPUTER- SIMULATION CONTROL OF A COMBINED FLOOR HEATING- COOLING SYSTEM Room temp. -Humidity Supply Limiter Outside temp. Mixing valve Return VIVALDI Boiler Chiller Valves Operation Temperature interval Pump running Operation time Mai to September Mean water temperature according to outside temperature 24 hours C % % % <,,, ,3 3,9 1, , 87,6 91,6-26,7 6,3 5, , 1,7 1,3 >27,,5,1 hours % ART MUSEUM BREGENZ

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 o C to 22 o C Room temperature in summer 22 o C to 26 o C, occasional up to 28 o C Design load persons pr. day, 2 hours Displacement ventilation <,2 h -1 Floor area 2.8 m², 4 floors 28. m plastic pipes embedded in walls and floor slabs ART MUSEUM BREGENZ 3.75 m² floor area 4.7 m² embedded pipes Condensing boiler Ventilation 75 m 3 /h per floor (first design was. m 3 /h ART MUSEUM IN BREGENZ ART MUSEUM BREGENZ C Okt 3. Okt ART MUSEUM BREGENZ - Measurements V 2 5-1G??? -R!! V Air Temp. 4. Okt 5. Okt 6. Okt 7. Okt 8. Okt 9. Okt 1. Okt 11. Okt 12. Okt t-luft-5min-mean t-boden-5min-mean rf-5min-mean Humidity Floor Temp 13. Okt 14. Okt 15. Okt 1 % Office building Stuttgart m² 3-4 floors Operable windows Co-generation Solar collectors Absorption cooling Free cooling Compressor cooling Displacement ventilation

9 Air supply Integrated convector for heating Displacement ventilation Data transmission Air temperature sensor Operative temperature sensor Stuttgart Data transmission Stuttgart Luft Operative Taupunkt Außen 35 Operative temperatursensor Temperatur [ C] Zeit

10 Stuttgart Stuttgart , O1-Operative Büro 4. Stock Fenster-Ost O-Operative Büro 5. Stock Fenster-West F1-Fläche 4. Stock Rucklauf O6-Operative Büro 5. Stock Fenster-Ost Stuttgart BUILDING 3 4th floor window west 4th floor window south 5th floor window west 5th floor window east 5th floor middle meeting room all offices except middle 26 1 Temperatur [ C] Jul 24. Jul. Jul. Jul 26. Jul Zeit 26. Jul 27. Jul 27. Jul 28. Jul 28. Jul 29. Jul percentage in operative temperature ranges according to DIN < >27 change in operative temperature during a day (8-18) [%] STUTTGART BUILDING 3 4th floor window west 4th floor window south 5th floor window west 5th floor window east 5th floor middle meeting room all offices except middle <1 (1-2) (2-3) (3-4) (4-5) (5-6) >6 Office building in Hamburg 14. m² 7.5 m² slab cooling Baseboard heaters 2 ach, 18 C Operable windows Transportation of modules

11 INSTALLATION PRE- FABRICATION PRE-FABRICATION CONCLUSIONS Hydraulic heating/cooling system with pipes embedded in the building structure is an interesting 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?