Heating and Cooling 1 • • Coordinator: Karel Kabele, kabele@fsv.cvut.cz, CTU in Prague • • • Contributors: Eric Willems, Erwin Roijen, Peter Op 't Veld, P.OpTVeld@chri.nl Camilla Brunsgaard, cbru@create.aau.dk & Mary-Ann Knudstrup, mak@create.aau.dk, Aalborg University, Per Kvols Heiselberg, ph@civil.aau.dk, Tine S. Larsen, Olena K. Larsen, Rasmus Lund Jensen (AAU) Arturas Kaklauskas, Arturas.kaklauskas@st.vgtu.lt, Audrius Banaitis, Audrius.banaitis@vgtu.lt , Vilnius Geniminas Technical University (VGTU) Marco Perino, marco.perino@polito.it, Gianvi Fracastoro, Stefano Corgnati, Valentina Serra (POLITO) Werner Stutterecker, werner.stutterecker@fh-burgenland.at, (FH-B) Mattheos Santamouris, msantam@phys.uoa.gr, Margarita Asimakopoulos, Marina Laskari, marlaskari@googlemail.com, (NKUA) Zoltan Magyar, zmagyar@invitel.hu, Mihaly Baumann, Aniko Vigh, idesedu.pte@gmail.com (PTE) Manuela Almeida, malmeida@civil.uminho.pt, Sandra Silva, sms@civil.uminho.pt , Ricardo Mateus, ricardomateus@civil.uminho.pt, University of Minho (UMINHO) Piotr Bartkiewicz, piotr.bartkiewicz@is.pw.edu.pl, Piotr Narowski, piotr.narowski@is.pw.edu.pl (WUT) Matthias Haase, matthias.Haase@sintef.no, (NTNU) Karel Kabele, kabele@fsv.cvut.cz, Pavla Dvořáková, pavla.dvorakova@fsv.cvut.cz, (CTU – FCE) • • • • • • • • • 2 LECTURE 3 ACTIVE SPACE HEATING AND COOLING 3 Heat emitters (radiators, convectors, tubular, radiant heating (stripes, panels), dark and light infrared radiant pipes, stoves). 4 Heating equipment • Heat source - heat transfer medium - heat emitter • Classification of the systems – local – floor – central – district 5 Heat emitters Heat emitters Convectors Radiators Banks of Pipes Fan convectors Natural Off peak storage Columns Radiant panels Panels 6 Convectors Natural Fan-convectors Floor Wall 7 Radiators 8 Control limits Large mass = heating unresponsive low mass = responsive heating Mass = storage Responsive heating control important to make use of solar gains Water content radiator G radiator G Panel radiator P today Heat insulation (old buildings) Heat insulation standard 1995 (new buildings) Steel radiator S Heat insulation Standard 2000 9 Thermal output * radiator temperature, 200C room temperature Convection share Radiation share Single panel radiator, without convector Radiator (modular) Double panel radiator, with three convectors Finned tube convector 10 Off-peak storage • Static • Dynamic • Convector • Radiator 11 Air flow patterns prof.Ing.Karel Kabele,CSc. 12 Radiant panels • Low temperature • heaters max 110 °C (water, steam, el.power) • High temperature • dark - about 350°C - radiant tube heating system (gas) • light - about 800 °C - flameless surface gas combustion 13 Heat emitters • Design principles – Heating output – Location – Covering - furniture – Connection to the pipe system – Type 14 Heat emitters design • Covering = changes in the output 100% 95% 110% 87% Connection to the piping system 100% 100% 90% 85% 15 SPACE HEATING AND COOLING 16 Low-temperature radiant heating High-temperature radiant cooling • Underfloor, wall and/or ceiling heating/cooling • Embeded surfaces • TABS • Snowmelt systems 17 Low - temperature radiant heating • floor, wall and/or ceiling with embedded pipes or el.wires in concrete slab – Temperature distribution Underfloor heating Radiators Ideal temper ature Ideal temper ature Underfloor heating 125BEE1_2008/2009 prof.Ing.Karel Kabele,CSc. 18 Radiators Radiant heating/cooling • Output – Limited surface temperature limited output cca 100 W.m-2 • Energy savings – Lower air temperature lower heat losses • Control – Low temperature difference autocontrol effect 19 Underfloor heating • History 20 Low/high - temperature radiant heating/cooling • Floor structure Insulating strip between wall and flooring Finished flooring Concrete slab min 65mm Reinforcement Pipes Thermal insulation 20-80mm Supporting floor structure Humidity seal 21 Underfloor heating - structure TYP B TYP A TYP C 22 Low - temperature radiant heating • Technical solution – Pipe layout 23 Underfloor heating - examples 24 Wall heating • Embedded pipes - inner wall side • Higher surface temperature on both sides • Furniture layout • Rooms with given use of space: swimming pools, entrance areas, corridors • not possible or desirable to use conventional heating surfaces: prisons, hospitals,… • Possibility to use the system for cooling 25 Wall heating - Design process • determination of the areas, applicable to this type of heating; • determine the desired maximum surface temperature; • calculate the heat loss room analogy for underfloor heating without losing the wall with wall heating; • verification of the achievable performance of surfaces and temperature • compared to heat loss, or draft supplementary heating surfaces. • select the type of wall heating, wet or dry system, pipe or capillaries; • design spacing and temperature parameters of heat transfer fluid; • hydraulic calculation. 26 Wall heating - temperatures • From the point of thermal comfort it is like radiators heating • Maximum surface temperature 35 - 50 °C according to local conditions. • For surface temperatures above 42 ° C can be painful contact. • size of losses to the outside, impact on the neighboring room • Some manufacturers recommend and design system for the surface temperature of 35 ° C 27 Technical solution A – pipes diameter 10-14 mm • Wet • Dry B – capillary mats Pipes diameter 6 mm , rozteč 30-50 mm • Wet 28 Thermally Activated Building Structures (TABS) • With or without phase change material • Cooling capacity can limit the use of system • Control of room conditions? 29 Thermal activation of building structure (TABS) - National technical library (Prague) foto: Václav Nývlt, Technet.cz 30 Special case HEATING OF THE BASEMENT OF ICE SURFACE 31 Realization 32 „Floor“ structure Ice 50 mm Concrete 240 mm Cooling -16/-12°C; 160 W/m2 EPS 250 mm Concrete 250 mm 33 34 „Floor“ structure with heating system Ice 50 mm Concrete 240 mm Cooling -16/-12°C 160 W/m2 EPS 250 mm Concrete 250 mm Heating 10/8 °C; cca 10 W/m2 35 36 Heating of outdoor surfaces Snowmelt system Pipe spacing 15-50cm Temperature 50-80°C Use of antifreeze Thermal output according to the amout of snow and outdoor temperature Large thermal inertia Mechanical resistance 37 • Air heating/cooling systems – circulating, ventilating. • Integration of heating/cooling systems. 38