Heating and Cooling 1
Coordinator: Karel Kabele, CTU in Contributors: Eric Willems, Erwin Roijen, Peter Op 't Veld, Camilla Brunsgaard, & Mary-Ann Knudstrup, Aalborg University, Per Kvols Heiselberg, Tine S. Larsen, Olena K. Larsen, Rasmus Lund Jensen Arturas Kaklauskas, Audrius Banaitis, Vilnius Geniminas Technical University Marco Perino, Gianvi Fracastoro, Stefano Corgnati, Valentina Serra Werner Stutterecker, Mattheos Santamouris, Margarita Asimakopoulos, Marina Laskari, Zoltan Magyar, Mihaly Baumann, Aniko Vigh, Manuela Almeida, Sandra Silva, Ricardo Mateus, University of Minho Piotr Bartkiewicz, Piotr Narowski, Matthias Haase, Karel Kabele, Pavla Dvořáková, (CTU – 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 6
Convectors 7 Natural Fan-convectors Floor Wall
Radiators 8
9 Control limits Panel radiator P Steel radiator S today Heat insulation (old buildings) Heat insulation standard 1995 (new buildings) Heat insulation Standard 2000 Water content radiator Large mass = heating unresponsive low mass = responsive heating G radiator G Mass = storage Responsive heating control important to make use of solar gains
10 * radiator temperature, 20 0 C room temperature Radiation share Convection share Single panel radiator, without convector Radiator (modular) Double panel radiator, with three convectors Finned tube convector Thermal output
Off-peak storage Static Dynamic Convector Radiator 11
12 Air flow patterns prof.Ing.Karel Kabele,CSc.
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 %87%110%95% 100% 90%85% l Connection to the piping system
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
18 Low - temperature radiant heating floor, wall and/or ceiling with embedded pipes or el.wires in concrete slab floor, wall and/or ceiling with embedded pipes or el.wires in concrete slab – Temperature distribution 125BEE1_2008/2009prof.Ing.Karel Kabele,CSc. Ideal temper ature Radiators Underfloor heating Ideal temper ature Underfloor heating 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 21 Insulating strip between wall and flooring Finished flooring Concrete slab min 65mm Thermal insulation 20-80mm Pipes Humidity seal Reinforcement Supporting floor structure
Underfloor heating - structure 22 TYP A TYP B TYP C
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 °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 mm Wet Dry B – capillary mats Pipes diameter 6 mm, rozteč mm Wet 28
With or without phase change material Cooling capacity can limit the use of system Control of room conditions? Thermally Activated Building Structures (TABS) 29
Thermal activation of building structure (TABS) - National technical library (Prague) 30 foto: Václav Nývlt, Technet.czTechnet.cz
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/m 2 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/m 2 EPS 250 mm Concrete 250 mm Heating 10/8 °C; cca 10 W/m 2 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