Application of Radiant Cooling Systems. Professor Bjarne W. Olesen, Ph.D Department of Civil Engineering. Technical University of Denmark

Transcription

1 Application of Radiant Cooling Systems Professor Bjarne W. Olesen, Ph.D Department of Civil Engineering. Technical University of Denmark Seminar outline Basics for Radiant systems System types, Comfort Standards for Radiant Heating and Cooling Systems Determination of Heating and Cooling Capacity Control of radiant cooling systems Construction and Installation Technologies Examples Q&A

2 Frank Lloyd Wright's Usonian Houses 1930 s HISTORY A lightweight floor slab was used and the traditional basement was dispensed with. By using steam or hot water piping, it became possible to heat the floor, therefore eliminating the need for radiators. The overall result was heat without a draft or temperature variation of the most comfort - cool head and warm feet. c. 10,000 B.C., China c. 10,000 B.C., China, the word kang, can be traced back to the 11th century B.C. and originally meant, to dry before it became known as a heated bed. c. 5,000 B.C., evidence of baked floors are found foreshadowing early forms of kang and dikang (heated floor) later ondol (warm stone) in China and Korea, respectively. HISTORY c. 1904, Liverpool Cathedral heated with system based on the hypocaust principles. Hypocausts were used from the third century B.C. in ancient Europe.

3 1. Screed 2. Pipes 3. Plastic foil 4. Insulation 5. Levelling 6. Concrete COMFORT-PERFORMANCE No cooling decreased performance Low energy costs Low operation costs Full Air-Conditioning Constant temperature Draught, Noise, SBS High energy costs High operation costs Thermo-Active-Building-Systems Temperature ramps Reasonable energy costs Low operation costs

4 What is Low Temperatur Heating/ High Temperature Cooling? Heat exchange through large surfaces (floor, ceiling, walls) Supply water temperatures: Heating: C ( F) Cooling: C (61 74 F) temperature limited by dew-point to avoid condensation) Wide range of systems, solutions both for residential and non-residential buildings 7 COMBINATION WITH LOW ENERGY SOURCES Day Cooling method Heating supply temp. : C heat pumps condensing boiler ground coupling waste heat solar energy Cooling supply temp. : C reversible heat pump ground coupling free cooling air cooled chillers Night Ground water Geothermal heat/coolth Night air Cooling unit 8

5 CONCEPTS OF RADIANT HEATING AND COOLING SYSTEMS Heating - Cooling panels Surface systems Embedded systems Suspended cooled ceilings

6 Suspended cooled ceilings Capillary Tubes Radiant surface heating and cooling systems Floor Wall Ceiling Thermo Active Building Systems Floor Room Window Reinforcement Concrete Room Pipes

7 GENERAL THERMAL COMFORT Personal factors Clothing Activity Environmental factors Air temperature Mean radiant temperature Air velocity Humidity

8 Mean Radiant Temperature t r = ΣF p-i t si F p-i = Angle factor from person to surface i t si = Surface temperature of surface i ΣF p-i = 1 Mean Radiant Temperature Figure 2.2 Mean value of angle factor between a seated person and a) horizontal rectangle b) vertical rectangle Figure 2.3 mean value of angle factor between a standing person and a) horizontal rectangle b) vertical rectangle

9 GENERAL THERMAL COMFORT FLOOR TEMPERATURE OPERATIVE TEMPERATURE t o = (h c t a + h r t r )/(h c + h r ) t o = 0.5t a + 0.5t r ( low air velocity) t a = Air temperature t r = Mean radiant temperature h c = Convective heat exchange coefficient h r = Radiative heat exchange coefficient 1 (1.8F) degree change of floor temperature will change operative temperature 0.2 (0.4F) degree

10 MODERATE ENVIRONMENTS GENERAL THERMAL COMFORT PMV / PPD, OPERATIVE TEMPERATURE LOCAL THERMAL DISCOMFORT Radiant temperature asymmetry Draught Vertical air temperature difference Floor surface temperature Determination of Heating and Cooling Capacity

11 SURFACE HEATING AND COOLING Heat transfer coefficient 11,5 11,0 11,0 8,0 8,0 10,5 9,5 8,5 7,5 W/m 2 K 6,5 Heating Cooling 7,0 Floor 6,0 Ceiling 5,5 Wall SURFACE HEATING AND COOLING Max. - Min. Surface temperature o C Heating Cooling Floor Ceiling Perimeter Wall

12 MAXIMUM HEATING AND COOLING CAPACITY Heating Cooling Floor Ceiling Perimeter Wall W/m 2 Heating/ cooling capacity, ISO ALUMINUM HC device: Floor Heating & Cooling (type B), R=0.01~0.1, T=150 & 300 Heat exchange [W/m2] T=150, R=0.01 T=150, R=0.1 T=300, R=0.01 T=300, R= Heating/cooling medium differential temperature θh=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

13 Method for verification of FEM and FDM calculation programs Method for verification of FEM and FDM calculation programs

14 Radiant Floor Cooling More than 100 W/m 2 or 32 Btu/ft 2 h TABS Thermo Active Building Systems Room Window Floor Insulation Concrete Pipe Reinforcement Room

15 Control of radiant heating and cooling systems

16 CONTROL OF A COMBINED FLOOR HEATING-COOLING SYSTEM Room temp. -Humidity Supply Limiter Outside temp. Mixing valve Return VIVALDI Boiler Chiller Valves CONTROL COOLING C 30 degc F 18 64, , , , , , , , , , Operative Temperature 15 2-Floor temperature 5 3-Min. Floor temp. t4-water temperature t 5-Dewpoint temp TIME hours

17 Control of a combined floor heating-cooling system with individual room control Room sensor Control unit Valve Temperature -Humidity Manifold Floor temp. Mixing valve Supply Pump Limiter Return Control Outside temperature Boiler Chiller Shut off valves SELF CONTROL Floortemperature at 20 C Roomtemperature degc F 18 64, , , , , , , , , , C ,3 80 W/m? 31,9 Heat load 38,4 23,9 40 W/m? 26,2 29,4 22,1 20 W/m? 23,3 24,9 10 W/m? 22,5 21,7 21,1 Heat. level temp. carpet Heat. level temp. tiles Floortemperature

18 SELF CONTROL % decrease in heat output by 1 K room temperature increase % W/m? Heat load W/m? W/m? W/m? Floor temperature Heat. level temp. tiles Radiant surface heating and cooling systems Floor Wall Ceiling Thermo Active Building Systems (TABS) Window Floor Room Reinforcement Concrete Room Pipes

19 The analysed building West room Office building Width of the room: 3.6 m Window portion of the outside wall: 50%

20 Internal heat sources Monday to Friday 600 heat production [W] W = 27.8 W/m² 8.6Btu/ft2 50% Radiation 50% Konvection 100g/h moisture daytime [h] Time of operation Four different schedules 24 hour 8:00-17:00 18:00-06:00 22:00-06:00

21 Intermittent operation of circulation pump Pump on for 1 hour Pump off for 1 hour Pump on for ½ hour Pump off for ½ hour Pump on for ¼ hour - Pump off for ¾ hour Control of water temperature degc F 18 64, , , , , , , , , , Supply water temperature equal to internal dew point temperature. Supply water temperature a function of outside temperature according to the equation: t supply 1,3*0,4* 20 t 20 external Average water temperature a function of outside temperature according t average 1,3*0,4* to: 20 texternal 20 Supply water temperature constant equal to: 18 C, 20 C and 22 C Average water temperature constant equal to: 18 C, 20 C and 22 C

22 Evaluation parameters Range of operative temperatures Pump running time Energy consumption Operative temperature range, May to September Different control concepts for water temperature, Time of operation 18:00-6:00 Uhr >27 Operative temperature range [%] Tsup = Tdp 38 Pump Tsup = F(ext) 33 Pump Tavg = F(ext) 14 Pump Tavg = 22 C Control of water temperature Pump Tavg = 20 C Pump Tavg = 18 C <20 Pump % degc F 18 64, , , , , , , ,6 Pump 28 82, ,

23 Energy consumption and pump running hours, May to September Different control concepts for water temperature, Time of operation 18:00-6:00 Uhr 2000 Energy consumption, kwh (Hours) Heating Cooling Pump hours degc F 18 64, , , , , , , , , , Tsup = Tdp Pump Tsup = F(ext) Pump Tavg = F(ext) Pump Tavg = 22 C Pump Tavg = 20 C Pump Tavg = 18 C Pump Control of water temperature Construction and Installation Technologies Examples

24 Transportation of modules

25 Installation pressure test 49 Prefabrication 50

26 Thermo active hollow-core slab ThermoMax Produced in Denmark by Spæncom 1.2 m wide, thicknes 220, 270, 320 and 400 mm 20 mm PEX-pipes PSO-ELFORSK/COWI (2012) 51 Industry

27 Radiant Floor Cooling Airport Bangkok

28 Airport Bangkok Airport Bangkok

29 Airport Bangkok Installation of PEX pipes June

30 Terminal building June T supplyw = 13 o C T a = 16 o C T d = 10 o C

31 ART MUSEUM BREGENZ 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 250 persons pr. day, 2 hours Displacement ventilation < 0,2 h -1 Floor area m², 4 floors m plastic pipes embedded in walls and floor slabs

32 ART MUSEUM BREGENZ m² floor area m² embedded pipes Condensing boiler Ventilation 750 m 3 /h per floor (first design was m 3 /h ART MUSEUM IN BREGENZ

33 ART MUSEUM BREGENZ ART MUSEUM BREGENZ

34 Balanced Office Building (BOB.1) Aachen, Germany Gross floor area 2,151 m² 4 storeys Efficiently insulated external envelope Ground-coupled heating and cooling with TABS Ventilation system with heat recovery Daylight-controlled lighting Rainwater collection for use in toilet flushing Energy concept in BOB.1

35 cooling period in BOB.1 Dockland, Hamburg

36 6 storeys, central open space m 2 Natural & mechanical ventilation Combined radiant floor heating/cooling and convectors under windows Viborg Town Hall Photo: Henning Larsen Architects 72

37 Viborg Town Hall 73 Graphics: Viborg Townhall brochure & COWI m2 IDOM Company Headquaters, Madrid, Spain Natural & Mechanical ventilation External solar shading & green facade TABS combinned with free cooling (covers kwh/m2) Energy use (kwh/m²y) IDOM HQ CTE - MADRID % Heating + DHW 27,35 77,00-64,5 Cooling 12,58 85,00-85,2 Lighting 11,37 34,00-66,6 Total 51,30 196,00-73,8 74

38 IDOM Company Headquaters, Madrid, Spain 75 Radiant Floor Cooling OPERA HOUSE SHOPPING CENTER MUSEUM

39 Technical University of Denmark Yearly indoor comfort evaluation and energy consumption, and assessment of thermal activated building systems in Middelfart Sparekasse.

40 Opera House in Copenhagen Summer indoor climate in Foyer Radiant floor cooling with stone cover down the structural slabs to reduce peak cooling load High air change by displacement ventilation system. Humidity control prevents condensation on floor. Slide 79 References / South, West Europe Modern Old Port of Savona, NW coast of Italy Underfloor heating for 140 high-end residential apartments and shopping area at ground level Dolce Vita Tejo, Lisbon, Portugal one of Europe s largest shopping centres to be built, heating and cooling by Uponor

41 References / Nordic The world s most modern opera house in Oslo, Norway Uponor ventilation ducts and floor heating Nupurinkartano, Espoo, Finland first turnkey bedrock heating/cooling in Finland Renovation with underfloor heating and tap water in Västerås, Sweden a 1978 office building turned into 50 apartments and 13 unique terraced houses on the rooftop Industrial heating/cooling application: BWM World Munich, Germany m² of floor, glass and steel, architecture in the BWM museum 5,000 m² of industrial radiant cooling and heating with PE-Xa pipes integrated into the hall floor = massive invisible cooling or heating panel Full architectural freedom provided: An experience which appeals to all senses, allowing visitors to experience the fascination of mobility Energy-saving and environmentally friendly operation

42 Sun shading and daylight penetration RADIANT VAV

43 Energy Thermal Comfort

44 DOE-USA

45 DOE-USA DOE-USA

46 COOPER UNION NEW YORK First costs

47 REHVA GUIDEBOOK NO: 7 Jan Babiak-Bjarne W. Olesen-Dusan Petras Low Exergy Hydronic Radiant Heating and Cooling Why? Water based systems Low temperature heating - High temperature cooling More economical to move heat by water: Greater heat capacity than air Much smaller diameter pipes than air-ducts Electrical consumption for circulation pump is lower than for fans Lower noise level Less risk for draught Lower building height Higher efficiency of energy plant But Reduced capacity? Acoustic? Latent load?