COMFORT-PRODUCTIVITY Building costs COMFORT-PERFORMANCE. Radiant Heating and Cooling Systems for Better Comfort and Energy Efficiency INDOOR - OUTDOOR

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1 Radiant Heating and Cooling Systems for Better Comfort and Energy Efficiency Professor Bjarne W. Olesen, PhD Director International Centre for Indoor Environment and Energy Department of Civil Engineering Technical University of Denmark INDOOR - OUTDOOR Highest exposure to the indoor environment People spend ~90 % of the time indoors during work, during transportation and at home International Centre for Indoor Environment And Energy 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 COMFORT-PRODUCTIVITY Building costs People 100 Maintenance 10 Financing 10 Energy 1 Thermo-Active-Building-Systems Temperature ramps Reasonable energy costs Low operation costs

2 CONCEPTS OF RADIANT HEATING AND COOLING SYSTEMS Suspended cooled ceilings Heating - cooling panels Surface systems Embedded systems Floor Radiant surface heating and cooling systems Wall Ceiling Embedded piping systems Thermo Active Building Systems Floor Room Window Free use of space No cleaning Safety Comfort Energy Reinforcement Concrete Room Pipes

3 OPERATIVE TEMPERATURE SURFACE HEATING AND COOLING Heat transfer coefficient 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 11,0 7,0 6,0 11,0 8,0 8,0 11,5 10,5 9,5 8,5 7,5 6,5 5,5 Wall W/m 2 K Heating Cooling Floor Ceiling

4 Types of systems, heating cooling capacity 1. Screed 2. Pipes 3. Plastic foil 4. Insulation 5. Levelling 6. Concrete Heat exchange coefficient between surface and space Total heat exchange coefficient W/m².K Acceptable surface temperature C Maximum capacity W/m² Heating Cooling Max. Heating Min. Cooling Heating Cooling Floor Perimeter Occupied Zone Wall 8 8 ~ Ceiling ~ Thermal resistance method System modules

5 Heating/ cooling capacity, EN1264 and EN 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 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 Heat exchange [W/m2] Floor Heating (& Cooling) (type G), R=0.01 ~0.1, T=150, 300 qi (T=150, R=0) 70 qe (T=150, R=0) qi (T=300, R=0) qe (T=300, R=0) qi (T=150, R=0.1) qe (T=150, R=0.1) qi (T=300, R=0.1) qe (T=300, R=0.1) Control of a combined floor heating-cooling system with individual room control Room sensor Mixing valve Valve Manifold Supply Pump Control unit Limiter Return Floor temp. Control Temperature -Humidity Outside temperature Heating/cooling medium differential temperature ΔθH=θH-θi [ C] Figure 4.21 Heat exchange between the surface (with ceramic tiles, wooden parquets or carpet and no covering) and the space when steel heat conductive device used. Thermal insulation of 3cm from back side. Boiler Shut off valves Chiller

6 Radiant Floor Cooling Airport Bangkok Airport Bangkok Airport Bangkok

7 Airport Bangkok Lisboa Dolce Vita Tejo

8 Lisboa Dolce Vita Tejo FLOOR COOLING IN SOUTHERN EUROPE Computer Simulation (IDA Indoor Climate and Energy 3.0) Simulation period from April 20th to November 15th Variation of one parameter at a time Variation of the location Parameter Study Location Study Dwelling Types Room Orientation Control Strategy Air Handling Unit Internal Loads Shading Levels Floor Covering Floor System Reference conditions Rome T s T pd limits cooling 0.8 h -1 8 to 23h else 0.3 h -1 Int. Loads from 8 to 23h No Dehumidification 50% Shading Santander Braganca Porto Madrid Faro Sevilla Barcelona Torino Venice Rome Palermo

9 Location Study Representative Cities No dehum. TABS Thermo Active Building Systems Room Window Floor Insulation Concrete Pipe Reinforcement Room Concept of Thermo Active Building Systems

10 The analysed building West room Office building CONTROL OF WATERTEMPERATURE Supply water temperature is a function of outside temperature according to the equation: t 0,52 * 20 t 20 1,6 * ( t 22) C (case 801) sup ply external o Width of the room: 3.6 m Window portion of the outside wall: 50% Average water temperature is a function of outside temperature according to: t average 0,52 * 20 texternal 20 1,6 * ( to 22) C (case 901) Average water temperature is constant and equal to: 22 C in summer and 25 C in winter. Supply water temperature is a function of outside temperature according to the equation: t sup ply 0,35 * 18 texternal 18 C summer (case 1401) t 0,45 * 18 t 18 C winter (case 1401) sup ply external PERFORMANCE EVALUATION Range of operative temperature Pump running time Energy consumption Operative temperature range [%] Operative temperature range, May to September Different control concepts for water temperature, Time of operation 18:00-6:00 Uhr > <20 Pump % Tsup = Tdp Pump Tsup = F(ext) Pump Tavg = F(ext) Pump Tavg = 22 C Control of water temperature Pump Tavg = 20 C Pump Tavg = 18 C Pump

11 CONTROL OF WATER TEMPERATURE SUMMER Operative temperature May to September Water temperature control. Time of operation 6 pm to 6 am ART MUSEUM BREGENZ Venezia Würzburg Range of operative temperature % > < Tsup= f(ti,te) Tave= f(ti,te) Tave= 22 C Tsup= f(te) Tsup= f(ti,te) Tave= f(ti,te) Tave= 22 C Tsup= f(te) Control methods 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 ART MUSEUM BREGENZ m² floor area m² embedded pipes Condensing boiler Ventilation 750 m 3 /h per floor (first design was m 3 /h

12 ART MUSEUM IN BREGENZ ART MUSEUM BREGENZ ART MUSEUM BREGENZ M+W Zander Stuttgart, Germany - TABS - in m 2 Offices

13 MW-Zander Measurements during normal operation Transmitters Air temperature sensor Operative temperature sensor Stuttgart Stuttgart , 2000 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 Temperatur [ C] Jul 24. Jul 25. Jul 25. Jul 26. Jul Zeit 26. Jul 27. Jul 27. Jul 28. Jul 28. Jul 29. Jul

14 Energy concept in BOB.1 Temperatures for one year in BOB.1 coolingperiodin BOB.1 Heating period in BOB.1

15 Yearly energie costs [ /m²a] Bestand BOB.1 Energy efficiency of BOB.1 60 % energy saving for lighting by daylight steering 94 % energy saving compared with conventional cooling The need of energy for heating, cooling, airventilation lighting and warm water is 27,8 kwh/m² per year 6. Energy sources Energy costs per m², per year: 2,7 EUR, per month 22,5 Cent Heizung Kühlung Lüftung Beleuchtung Pumpen Warmwasser Summe Developing Low Exergy Systems in the Tropics MECM LEO 125 kwh/m 2 year 100 ENERGY-10 Optimisation Super Low E. Building 100 (Malaysia, Singapore, Thailand, Indonesia) Climates where : Evaporative cooling is not possible Earth coupling is not useful Dehumidification is necessary Ambient temperatures are above internal comfort temperature Cooling is 100% and heating is zero Cooling Lights Other Total 51

16 ZEO Building (Zero Energy Office) Trickling PV roof : PV Powerplant and Cooling Tower High temp. cooling Supply temp. for concrete slab cooling is 18 C resulting in high COP of Chiller Concrete slab cooling Thermal comfort with C and ceiling/ 23 C 100% daylighting Light guiding façade and max. 8 meters deep offices Self-shading facade Set-back façade shades against direct solar radiation Section, Office B, version 3 Off coil temperature of chiller in increased from 7 o C to 18 o C increased COP of Chiller Embedded water pipes 23 C Outdoor Atrium 20 C Transm. 0.8 Lightshelf Blind reflecting light upwards Highly reflective ceiling Air ducts 22 C 23 C Transm. 0.5 No direct sky view 20 C Evaporator 15 C 20 C 15 C AHU

17 Trickling Cool Roof ~ 25 o C ~ 95% RH Sky Radiant Temperature o Cat night ~ 30 o C PV Roof Radiation Convection Evaporation 15 o ~ 25 o C Chiller Pump Chiller Condenser ( heat rejection ) Microsoft Excel Worksheet

18 PRE- FABRICATION PRE-FABRICATION 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?

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